Convert HA Guide to XML
This patch does the initial conversion of the High Availability Guide to XML from ASCIIdoc. No changes to the structure have been made; this is simply the XML that gets generated by asciidoc. This patch includes the following changes to the original HA Guide: - Content now appears in a single Docbook XML file, to be broken out in the next patch - Original ASCIIDoc files have been removed - pom.xml has been updated to reflect the new source - .gitignore has been updated so that it no longer ignores bk-ha-guide.xml This patch is simply to establish the new structure. To prevent front-end disruptions it includes all of the existing content, but the content hasn't been audited or broken out into individual files. For ease of review, that will be done in the next patch(es). (This patch also includes the corrections and changes that were originally part of https://review.openstack.org/#/c/93856/2, corrected so that list appears properly.) Implements: blueprint convert-ha-guide-to-docbook Change-Id: I0455716c037b5e6e698bfca72162aba29f339e8a
This commit is contained in:
Nicholas Chase
Andreas Jaeger
parent
fb21219680
commit
0d21ce440d
1
.gitignore
vendored
1
.gitignore
vendored
@ -4,7 +4,6 @@
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# Build results
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target/
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bk-ha-guide.xml
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publish-docs/
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generated/
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/build-*.log.gz
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@ -1,41 +0,0 @@
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This directory contains what's eventually intended to become reference
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documentation for OpenStack High Availability.
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Contrary to the rest of the documentation which is straight-up
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DocBook, this guide is being maintained, at least for the time being,
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in AsciiDoc. AsciiDoc processing is supported by the OpenStack Jenkins
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CI infrastructure, but not by the Maven toolchain. So as a stop-gap
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measure until such support becomes available, please do this if you
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want to build offline before you send a patch:
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1. Make your change to the AsciiDoc source file (.txt). The syntax
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should be self explanatory-and intuitive to anyone who's ever used
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something like Markdown or RST. The AsciiDoc cheatsheet is an
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extremely useful resource: http://powerman.name/doc/asciidoc
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2. Pipe your stuff through AsciiDoc. Here's one catch: AsciiDoc
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currently doesn't fully support DocBook 5, but the Maven toolchain
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requires it. So you'll have to run your AsciiDoc output through the
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"db4upgrade.xsl" stylesheet that ships with DocBook 5.
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3. Finally, indent your resulting XML with two spaces. This should
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produce a clean patch against bk-ha-guide.xml which you can then
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submit to Gerrit along with your .txt file patch.
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4. Add an "xml:id" attribute on the root <book> element. The Maven
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toolchain requires this.
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Here's a command line you can use with AsciiDoc, xsltproc, xmllint and
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sed to achieve all of the above:
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asciidoc -b docbook -d book -o - ha-guide.txt | \
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xsltproc -o - /path/to/db4-upgrade.xsl - | \
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xmllint --format - | \
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sed -e 's,^<book ,<book xml:id="bk-ha-guide" ,' \
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> bk-ha-guide.xml
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Admittedly, the sed hack is particularly ugly, but it does get the job
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done.
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After that, you should be able to build with "mvn clean
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generate-sources" as you normally would.
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@ -1,4 +0,0 @@
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[[ha-aa-automated-deployment]]
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=== Automate deployment with Puppet
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(Coming soon)
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@ -1,4 +0,0 @@
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[[ha-aa-computes]]
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=== OpenStack compute nodes
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(Coming soon)
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@ -1,66 +0,0 @@
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[[ha-aa-controllers]]
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=== OpenStack controller nodes
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OpenStack controller nodes contain:
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* All OpenStack API services
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* All OpenStack schedulers
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* Memcached service
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==== Run OpenStack API and schedulers
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===== API services
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All OpenStack projects have an API service for controlling all the resources in the Cloud.
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In Active / Active mode, the most common setup is to scale-out these services on at least two nodes
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and use load-balancing and virtual IP (with HAproxy & Keepalived in this setup).
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*Configure API OpenStack services*
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To configure our Cloud using Highly available and scalable API services, we need to ensure that:
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* You use Virtual IP when configuring OpenStack Identity endpoints.
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* All OpenStack configuration files should refer to Virtual IP.
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*In case of failure*
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The monitor check is quite simple since it just establishes a TCP connection to the API port. Comparing to the
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Active / Passive mode using Corosync & Resources Agents, we don’t check if the service is actually running).
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That’s why all OpenStack API should be monitored by another tool (i.e. Nagios) with the goal to detect
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failures in the Cloud Framework infrastructure.
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===== Schedulers
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OpenStack schedulers are used to determine how to dispatch compute, network and volume requests. The most
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common setup is to use RabbitMQ as messaging system already documented in this guide.
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Those services are connected to the messaging backend and can scale-out :
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* nova-scheduler
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* nova-conductor
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* cinder-scheduler
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* neutron-server
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* ceilometer-collector
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* heat-engine
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Please refer to the RabbitMQ section for configure these services with multiple messaging servers.
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==== Memcached
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Most of OpenStack services use an application to offer persistence and store ephemeral data (like tokens).
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Memcached is one of them and can scale-out easily without specific trick.
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To install and configure it, read the http://code.google.com/p/memcached/wiki/NewStart[official documentation].
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Memory caching is managed by oslo-incubator so the way to use multiple memcached servers is the same for all projects.
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Example with two hosts:
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----
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memcached_servers = controller1:11211,controller2:11211
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----
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By default, controller1 handles the caching service but if the host goes down, controller2 does the job.
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For more information about memcached installation, see the OpenStack
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Cloud Administrator Guide.
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@ -1,189 +0,0 @@
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[[ha-aa-db]]
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=== Database
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The first step is installing the database that sits at the heart of the
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cluster. When we talk about High Availability, we talk about several databases (for redundancy) and a
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means to keep them synchronized. In this case, we must choose the
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MySQL database, along with Galera for synchronous multi-master replication.
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The choice of database isn’t a foregone conclusion; you’re not required
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to use MySQL. It is, however, a fairly common choice in OpenStack
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installations, so we’ll cover it here.
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[[ha-aa-db-mysql-galera]]
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==== MySQL with Galera
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Rather than starting with a vanilla version of MySQL, and then adding
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Galera, you will want to install a version of MySQL patched for wsrep
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(Write Set REPlication) from https://launchpad.net/codership-mysql/0.7.
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The wsrep API is suitable for configuring MySQL High Availability in
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OpenStack because it supports synchronous replication.
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Note that the installation requirements call for careful attention. Read
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the guide https://launchpadlibrarian.net/66669857/README-wsrep
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to ensure you follow all the required steps.
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Installing Galera through a MySQL version patched for wsrep:
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1. Download Galera from https://launchpad.net/galera/+download, and
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install the *.rpms or *.debs, which takes care of any dependencies
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that your system doesn’t already have installed.
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2. Adjust the configuration:
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In the system-wide +my.conf+ file, make sure mysqld isn’t bound to
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127.0.0.1, and that +/etc/mysql/conf.d/+ is included.
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Typically you can find this file at +/etc/my.cnf+:
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----
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[mysqld]
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...
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!includedir /etc/mysql/conf.d/
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...
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#bind-address = 127.0.0.1
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----
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When adding a new node, you must configure it with a MySQL account that
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can access the other nodes. The new node must be able to request a state
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snapshot from one of the existing nodes:
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3. Specify your MySQL account information in +/etc/mysql/conf.d/wsrep.cnf+:
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----
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wsrep_sst_auth=wsrep_sst:wspass
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----
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4. Connect as root and grant privileges to that user:
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|
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----
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$ mysql -e "SET wsrep_on=OFF; GRANT ALL ON *.* TO wsrep_sst@'%' IDENTIFIED BY 'wspass'";
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----
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5. Remove user accounts with empty usernames because they cause problems:
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----
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$ mysql -e "SET wsrep_on=OFF; DELETE FROM mysql.user WHERE user='';"
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----
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6. Set up certain mandatory configuration options within MySQL itself.
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These include:
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|
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----
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query_cache_size=0
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binlog_format=ROW
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default_storage_engine=innodb
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innodb_autoinc_lock_mode=2
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innodb_doublewrite=1
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----
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7. Check that the nodes can access each other through the firewall.
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Depending on your environment, this might mean adjusting iptables, as in:
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|
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----
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# iptables --insert RH-Firewall-1-INPUT 1 --proto tcp --source <my IP>/24 --destination <my IP>/32 --dport 3306 -j ACCEPT
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# iptables --insert RH-Firewall-1-INPUT 1 --proto tcp --source <my IP>/24 --destination <my IP>/32 --dport 4567 -j ACCEPT
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----
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This might also mean configuring any NAT firewall between nodes to allow
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direct connections. You might need to disable SELinux, or configure it to
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allow mysqld to listen to sockets at unprivileged ports.
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|
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Now you’re ready to create the cluster.
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===== Create the cluster
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In creating a cluster, you first start a single instance, which creates
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the cluster. The rest of the MySQL instances then connect to
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that cluster:
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An example of creating the cluster:
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1. Start on +10.0.0.10+ by executing the command:
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|
||||
----
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# service mysql start wsrep_cluster_address=gcomm://
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----
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2. Connect to that cluster on the rest of the nodes by referencing the
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address of that node, as in:
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|
||||
----
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# service mysql start wsrep_cluster_address=gcomm://10.0.0.10
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||||
----
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||||
|
||||
You also have the option to set the +wsrep_cluster_address+ in the
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+/etc/mysql/conf.d/wsrep.cnf+ file, or within the client itself. (In
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||||
fact, for some systems, such as MariaDB or Percona, this may be your
|
||||
only option.)
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|
||||
An example of checking the status of the cluster.
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||||
|
||||
1. Open the MySQL client and check the status of the various parameters:
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|
||||
----
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||||
mysql> SET GLOBAL wsrep_cluster_address='<cluster address string>';
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mysql> SHOW STATUS LIKE 'wsrep%';
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||||
----
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||||
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||||
You should see a status that looks something like this:
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||||
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||||
----
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mysql> show status like 'wsrep%';
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+----------------------------+--------------------------------------+
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| Variable_name | Value |
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+----------------------------+--------------------------------------+
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||||
| wsrep_local_state_uuid | 111fc28b-1b05-11e1-0800-e00ec5a7c930 |
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||||
| wsrep_protocol_version | 1 |
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||||
| wsrep_last_committed | 0 |
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||||
| wsrep_replicated | 0 |
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||||
| wsrep_replicated_bytes | 0 |
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||||
| wsrep_received | 2 |
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||||
| wsrep_received_bytes | 134 |
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| wsrep_local_commits | 0 |
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||||
| wsrep_local_cert_failures | 0 |
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||||
| wsrep_local_bf_aborts | 0 |
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||||
| wsrep_local_replays | 0 |
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||||
| wsrep_local_send_queue | 0 |
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||||
| wsrep_local_send_queue_avg | 0.000000 |
|
||||
| wsrep_local_recv_queue | 0 |
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||||
| wsrep_local_recv_queue_avg | 0.000000 |
|
||||
| wsrep_flow_control_paused | 0.000000 |
|
||||
| wsrep_flow_control_sent | 0 |
|
||||
| wsrep_flow_control_recv | 0 |
|
||||
| wsrep_cert_deps_distance | 0.000000 |
|
||||
| wsrep_apply_oooe | 0.000000 |
|
||||
| wsrep_apply_oool | 0.000000 |
|
||||
| wsrep_apply_window | 0.000000 |
|
||||
| wsrep_commit_oooe | 0.000000 |
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||||
| wsrep_commit_oool | 0.000000 |
|
||||
| wsrep_commit_window | 0.000000 |
|
||||
| wsrep_local_state | 4 |
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||||
| wsrep_local_state_comment | Synced (6) |
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| wsrep_cert_index_size | 0 |
|
||||
| wsrep_cluster_conf_id | 1 |
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||||
| wsrep_cluster_size | 1 |
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||||
| wsrep_cluster_state_uuid | 111fc28b-1b05-11e1-0800-e00ec5a7c930 |
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| wsrep_cluster_status | Primary |
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| wsrep_connected | ON |
|
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| wsrep_local_index | 0 |
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| wsrep_provider_name | Galera |
|
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| wsrep_provider_vendor | Codership Oy |
|
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| wsrep_provider_version | 21.1.0(r86) |
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||||
| wsrep_ready | ON |
|
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+----------------------------+--------------------------------------+
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38 rows in set (0.01 sec)
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----
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||||
|
||||
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[[ha-aa-db-galera-monitoring]]
|
||||
==== Galera monitoring scripts
|
||||
|
||||
(Coming soon)
|
||||
|
||||
==== Other ways to provide a highly available database
|
||||
|
||||
MySQL with Galera is by no means the only way to achieve database HA.
|
||||
MariaDB (https://mariadb.org/) and Percona (http://www.percona.com/)
|
||||
also work with Galera. You also have the option to use Postgres, which
|
||||
has its own replication, or another database HA option.
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||||
@ -1,156 +0,0 @@
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[[ha-aa-haproxy]]
|
||||
=== HAproxy nodes
|
||||
|
||||
HAProxy is a very fast and reliable solution offering high availability, load balancing, and proxying
|
||||
for TCP and HTTP-based applications. It is particularly suited for web sites crawling under very high loads
|
||||
while needing persistence or Layer 7 processing. Supporting tens of thousands of connections is clearly
|
||||
realistic with today's hardware.
|
||||
|
||||
For installing HAproxy on your nodes, you should consider its http://haproxy.1wt.eu/#docs[official documentation].
|
||||
Also, you have to consider that this service should not be a single point of failure, so you need at least two
|
||||
nodes running HAproxy.
|
||||
|
||||
Here is an example for HAproxy configuration file:
|
||||
----
|
||||
global
|
||||
chroot /var/lib/haproxy
|
||||
daemon
|
||||
group haproxy
|
||||
maxconn 4000
|
||||
pidfile /var/run/haproxy.pid
|
||||
user haproxy
|
||||
|
||||
defaults
|
||||
log global
|
||||
maxconn 8000
|
||||
option redispatch
|
||||
retries 3
|
||||
timeout http-request 10s
|
||||
timeout queue 1m
|
||||
timeout connect 10s
|
||||
timeout client 1m
|
||||
timeout server 1m
|
||||
timeout check 10s
|
||||
|
||||
listen dashboard_cluster
|
||||
bind <Virtual IP>:443
|
||||
balance source
|
||||
option tcpka
|
||||
option httpchk
|
||||
option tcplog
|
||||
server controller1 10.0.0.1:443 check inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.2:443 check inter 2000 rise 2 fall 5
|
||||
|
||||
listen galera_cluster
|
||||
bind <Virtual IP>:3306
|
||||
balance source
|
||||
option httpchk
|
||||
server controller1 10.0.0.4:3306 check port 9200 inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.5:3306 check port 9200 inter 2000 rise 2 fall 5
|
||||
server controller3 10.0.0.6:3306 check port 9200 inter 2000 rise 2 fall 5
|
||||
|
||||
listen glance_api_cluster
|
||||
bind <Virtual IP>:9292
|
||||
balance source
|
||||
option tcpka
|
||||
option httpchk
|
||||
option tcplog
|
||||
server controller1 10.0.0.1:9292 check inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.2:9292 check inter 2000 rise 2 fall 5
|
||||
|
||||
listen glance_registry_cluster
|
||||
bind <Virtual IP>:9191
|
||||
balance source
|
||||
option tcpka
|
||||
option tcplog
|
||||
server controller1 10.0.0.1:9191 check inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.2:9191 check inter 2000 rise 2 fall 5
|
||||
|
||||
listen keystone_admin_cluster
|
||||
bind <Virtual IP>:35357
|
||||
balance source
|
||||
option tcpka
|
||||
option httpchk
|
||||
option tcplog
|
||||
server controller1 10.0.0.1:35357 check inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.2.42:35357 check inter 2000 rise 2 fall 5
|
||||
|
||||
listen keystone_public_internal_cluster
|
||||
bind <Virtual IP>:5000
|
||||
balance source
|
||||
option tcpka
|
||||
option httpchk
|
||||
option tcplog
|
||||
server controller1 10.0.0.1:5000 check inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.2:5000 check inter 2000 rise 2 fall 5
|
||||
|
||||
listen nova_ec2_api_cluster
|
||||
bind <Virtual IP>:8773
|
||||
balance source
|
||||
option tcpka
|
||||
option tcplog
|
||||
server controller1 10.0.0.1:8773 check inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.2:8773 check inter 2000 rise 2 fall 5
|
||||
|
||||
listen nova_compute_api_cluster
|
||||
bind <Virtual IP>:8774
|
||||
balance source
|
||||
option tcpka
|
||||
option httpchk
|
||||
option tcplog
|
||||
server controller1 10.0.0.1:8774 check inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.2:8774 check inter 2000 rise 2 fall 5
|
||||
|
||||
listen nova_metadata_api_cluster
|
||||
bind <Virtual IP>:8775
|
||||
balance source
|
||||
option tcpka
|
||||
option tcplog
|
||||
server controller1 10.0.0.1:8775 check inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.2:8775 check inter 2000 rise 2 fall 5
|
||||
|
||||
listen cinder_api_cluster
|
||||
bind <Virtual IP>:8776
|
||||
balance source
|
||||
option tcpka
|
||||
option httpchk
|
||||
option tcplog
|
||||
server controller1 10.0.0.1:8776 check inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.2:8776 check inter 2000 rise 2 fall 5
|
||||
|
||||
listen ceilometer_api_cluster
|
||||
bind <Virtual IP>:8777
|
||||
balance source
|
||||
option tcpka
|
||||
option httpchk
|
||||
option tcplog
|
||||
server controller1 10.0.0.1:8774 check inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.2:8774 check inter 2000 rise 2 fall 5
|
||||
|
||||
listen spice_cluster
|
||||
bind <Virtual IP>:6082
|
||||
balance source
|
||||
option tcpka
|
||||
option tcplog
|
||||
server controller1 10.0.0.1:6080 check inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.2:6080 check inter 2000 rise 2 fall 5
|
||||
|
||||
listen neutron_api_cluster
|
||||
bind <Virtual IP>:9696
|
||||
balance source
|
||||
option tcpka
|
||||
option httpchk
|
||||
option tcplog
|
||||
server controller1 10.0.0.1:9696 check inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.2:9696 check inter 2000 rise 2 fall 5
|
||||
|
||||
listen swift_proxy_cluster
|
||||
bind <Virtual IP>:8080
|
||||
balance source
|
||||
option tcplog
|
||||
option tcpka
|
||||
server controller1 10.0.0.1:8080 check inter 2000 rise 2 fall 5
|
||||
server controller2 10.0.0.2:8080 check inter 2000 rise 2 fall 5
|
||||
----
|
||||
|
||||
After each change of this file, you should restart HAproxy.
|
||||
@ -1,39 +0,0 @@
|
||||
[[ha-aa-network]]
|
||||
=== OpenStack network nodes
|
||||
|
||||
OpenStack network nodes contain:
|
||||
|
||||
* neutron DHCP agent
|
||||
* neutron L2 agent
|
||||
* Neutron L3 agent
|
||||
* neutron metadata agent
|
||||
* neutron lbaas agent
|
||||
|
||||
NOTE: The neutron L2 agent does not need to be highly available. It has to be
|
||||
installed on each Data Forwarding Node and controls the virtual networking
|
||||
drivers as Open vSwitch or Linux Bridge. One L2 agent runs per node
|
||||
and controls its virtual interfaces. That's why it cannot be distributed and
|
||||
highly available.
|
||||
|
||||
|
||||
==== Run neutron DHCP agent
|
||||
|
||||
OpenStack Networking service has a scheduler that
|
||||
lets you run multiple agents across nodes. Also, the DHCP agent can be natively
|
||||
highly available. For details, see http://docs.openstack.org/trunk/config-reference/content/app_demo_multi_dhcp_agents.html[OpenStack Configuration Reference].
|
||||
|
||||
==== Run neutron L3 agent
|
||||
|
||||
The neutron L3 agent is scalable thanks to the scheduler
|
||||
that allows distribution of virtual routers across multiple nodes.
|
||||
But there is no native feature to make these routers highly available.
|
||||
At this time, the Active / Passive solution exists to run the Neutron L3
|
||||
agent in failover mode with Pacemaker. See the Active / Passive
|
||||
section of this guide.
|
||||
|
||||
==== Run neutron metadata agent
|
||||
|
||||
There is no native feature to make this service highly available.
|
||||
At this time, the Active / Passive solution exists to run the neutron
|
||||
metadata agent in failover mode with Pacemaker. See the Active /
|
||||
Passive section of this guide.
|
||||
@ -1,2 +0,0 @@
|
||||
[[ha-using-active-active]]
|
||||
== HA using active/active
|
||||
@ -1,127 +0,0 @@
|
||||
[[ha-aa-rabbitmq]]
|
||||
=== RabbitMQ
|
||||
|
||||
RabbitMQ is the default AMQP server used by many OpenStack services. Making the RabbitMQ service
|
||||
highly available involves the following steps:
|
||||
|
||||
* Install RabbitMQ
|
||||
* Configure RabbitMQ for HA queues
|
||||
* Configure OpenStack services to use Rabbit HA queues
|
||||
|
||||
|
||||
==== Install RabbitMQ
|
||||
|
||||
This setup has been tested with RabbitMQ 2.7.1.
|
||||
|
||||
===== On Ubuntu / Debian
|
||||
|
||||
RabbitMQ is packaged on both distros:
|
||||
----
|
||||
apt-get install rabbitmq-server rabbitmq-plugins
|
||||
----
|
||||
|
||||
http://www.rabbitmq.com/install-debian.html[Official manual for installing RabbitMQ on Ubuntu / Debian]
|
||||
|
||||
===== On Fedora / RHEL
|
||||
|
||||
RabbitMQ is packaged on both distros:
|
||||
----
|
||||
yum install erlang
|
||||
----
|
||||
|
||||
http://www.rabbitmq.com/install-rpm.html[Official manual for installing RabbitMQ on Fedora / RHEL]
|
||||
|
||||
|
||||
==== Configure RabbitMQ
|
||||
|
||||
Here we are building a cluster of RabbitMQ nodes to construct a RabbitMQ broker.
|
||||
Mirrored queues in RabbitMQ improve the availability of service since it will be resilient to failures.
|
||||
We have to consider that while exchanges and bindings will survive the loss of individual nodes, queues
|
||||
and their messages will not because a queue and its contents is located on one node. If we lose this node,
|
||||
we also lose the queue.
|
||||
|
||||
We consider that we run (at least) two RabbitMQ servers. To build a broker, we need to ensure that all nodes
|
||||
have the same erlang cookie file. To do so, stop RabbitMQ everywhere and copy the cookie from rabbit1 server
|
||||
to other server(s):
|
||||
----
|
||||
scp /var/lib/rabbitmq/.erlang.cookie \
|
||||
root@rabbit2:/var/lib/rabbitmq/.erlang.cookie
|
||||
----
|
||||
|
||||
Then, start RabbitMQ on nodes.
|
||||
If RabbitMQ fails to start, you can’t continue to the next step.
|
||||
|
||||
Now, we are building the HA cluster. From rabbit2, run these commands:
|
||||
----
|
||||
rabbitmqctl stop_app
|
||||
rabbitmqctl cluster rabbit@rabbit1
|
||||
rabbitmqctl start_app
|
||||
----
|
||||
|
||||
To verify the cluster status :
|
||||
----
|
||||
rabbitmqctl cluster_status
|
||||
|
||||
Cluster status of node rabbit@rabbit2 ...
|
||||
[{nodes,[{disc,[rabbit@rabbit1]},{ram,[rabbit@rabbit2]}]},{running_nodes,[rabbit@rabbit2,rabbit@rabbit1]}]
|
||||
----
|
||||
|
||||
If the cluster is working, you can now proceed to creating users and passwords for queues.
|
||||
|
||||
|
||||
*Note for RabbitMQ version 3*
|
||||
|
||||
Queue mirroring is no longer controlled by the _x-ha-policy_ argument when declaring a queue. OpenStack can
|
||||
continue to declare this argument, but it won't cause queues to be mirrored.
|
||||
We need to make sure that all queues (except those with auto-generated names) are mirrored across all running nodes:
|
||||
----
|
||||
rabbitmqctl set_policy HA '^(?!amq\.).*' '{"ha-mode": "all"}'
|
||||
----
|
||||
|
||||
http://www.rabbitmq.com/ha.html[More information about High availability in RabbitMQ]
|
||||
|
||||
|
||||
==== Configure OpenStack services to use RabbitMQ
|
||||
|
||||
We have to configure the OpenStack components to use at least two RabbitMQ nodes.
|
||||
|
||||
Do this configuration on all services using RabbitMQ:
|
||||
|
||||
RabbitMQ HA cluster host:port pairs:
|
||||
----
|
||||
rabbit_hosts=rabbit1:5672,rabbit2:5672
|
||||
----
|
||||
|
||||
How frequently to retry connecting with RabbitMQ:
|
||||
----
|
||||
rabbit_retry_interval=1
|
||||
----
|
||||
|
||||
How long to back-off for between retries when connecting to RabbitMQ:
|
||||
----
|
||||
rabbit_retry_backoff=2
|
||||
----
|
||||
|
||||
Maximum retries with trying to connect to RabbitMQ (infinite by default):
|
||||
----
|
||||
rabbit_max_retries=0
|
||||
----
|
||||
|
||||
Use durable queues in RabbitMQ:
|
||||
----
|
||||
rabbit_durable_queues=false
|
||||
----
|
||||
|
||||
Use H/A queues in RabbitMQ (x-ha-policy: all):
|
||||
----
|
||||
rabbit_ha_queues=true
|
||||
----
|
||||
|
||||
If you change the configuration from an old setup which did not use HA queues, you should interrupt the service:
|
||||
----
|
||||
rabbitmqctl stop_app
|
||||
rabbitmqctl reset
|
||||
rabbitmqctl start_app
|
||||
----
|
||||
|
||||
Services currently working with HA queues: OpenStack Compute, OpenStack Block Storage, OpenStack Networking, Telemetry.
|
||||
@ -1,6 +0,0 @@
|
||||
[[ha-aa-storage]]
|
||||
=== Storage back ends for OpenStack Image Service and Block Storage
|
||||
|
||||
(Coming soon)
|
||||
|
||||
|
||||
@ -1,13 +0,0 @@
|
||||
[[ch-api]]
|
||||
=== API node cluster stack
|
||||
|
||||
The API node exposes OpenStack API endpoints onto external network (Internet).
|
||||
It must talk to the cloud controller on the management network.
|
||||
|
||||
include::ap-api-vip.txt[]
|
||||
include::ap-keystone.txt[]
|
||||
include::ap-glance-api.txt[]
|
||||
include::ap-cinder-api.txt[]
|
||||
include::ap-neutron-server.txt[]
|
||||
include::ap-ceilometer-agent-central.txt[]
|
||||
include::ap-api-pacemaker.txt[]
|
||||
@ -1,8 +0,0 @@
|
||||
[[s-api-pacemaker]]
|
||||
==== Configure Pacemaker group
|
||||
|
||||
Finally, we need to create a service +group+ to ensure that virtual IP is linked to the API services resources:
|
||||
|
||||
----
|
||||
include::includes/pacemaker-api.crm[]
|
||||
----
|
||||
@ -1,10 +0,0 @@
|
||||
[[s-api-vip]]
|
||||
==== Configure the VIP
|
||||
|
||||
First, you must select and assign a virtual IP address (VIP) that can freely float between cluster nodes.
|
||||
|
||||
This configuration creates +p_ip_api+, a virtual IP address for use by the API node (192.168.42.103) :
|
||||
|
||||
----
|
||||
include::includes/pacemaker-api_vip.crm[]
|
||||
----
|
||||
@ -1,64 +0,0 @@
|
||||
[[s-ceilometer-agent-central]]
|
||||
==== Highly available Telemetry central agent
|
||||
|
||||
Telemetry (ceilometer) is the metering and monitoring service in
|
||||
OpenStack. The Central agent polls for resource utilization
|
||||
statistics for resources not tied to instances or compute nodes.
|
||||
|
||||
NOTE: Due to limitations of a polling model, a single instance of this agent
|
||||
can be polling a given list of meters. In this setup, we install this service
|
||||
on the API nodes also in the active / passive mode.
|
||||
|
||||
|
||||
Making the Telemetry central agent service highly available in active / passive mode involves
|
||||
managing its daemon with the Pacemaker cluster manager.
|
||||
|
||||
NOTE: You will find at http://docs.openstack.org/developer/ceilometer/install/manual.html#installing-the-central-agent[this page]
|
||||
the process to install the Telemetry central agent.
|
||||
|
||||
|
||||
===== Add the Telemetry central agent resource to Pacemaker
|
||||
|
||||
First of all, you need to download the resource agent to your system:
|
||||
|
||||
----
|
||||
cd /usr/lib/ocf/resource.d/openstack
|
||||
wget https://raw.github.com/madkiss/openstack-resource-agents/master/ocf/ceilometer-agent-central
|
||||
chmod a+rx *
|
||||
----
|
||||
|
||||
You may then proceed with adding the Pacemaker configuration for
|
||||
the Telemetry central agent resource. Connect to the Pacemaker cluster with +crm
|
||||
configure+, and add the following cluster resources:
|
||||
|
||||
----
|
||||
include::includes/pacemaker-ceilometer_agent_central.crm[]
|
||||
----
|
||||
|
||||
This configuration creates
|
||||
|
||||
* +p_ceilometer-agent-central+, a resource for manage Ceilometer Central Agent service
|
||||
|
||||
+crm configure+ supports batch input, so you may copy and paste the
|
||||
above into your live pacemaker configuration, and then make changes as
|
||||
required.
|
||||
|
||||
Once completed, commit your configuration changes by entering +commit+
|
||||
from the +crm configure+ menu. Pacemaker will then start the Ceilometer Central Agent
|
||||
service, and its dependent resources, on one of your nodes.
|
||||
|
||||
===== Configure Telemetry central agent service
|
||||
|
||||
Edit +/etc/ceilometer/ceilometer.conf+ :
|
||||
----
|
||||
# We use API VIP for Identity Service connection :
|
||||
os_auth_url=http://192.168.42.103:5000/v2.0
|
||||
|
||||
# We send notifications to High Available RabbitMQ :
|
||||
notifier_strategy = rabbit
|
||||
rabbit_host = 192.168.42.102
|
||||
|
||||
[database]
|
||||
# We have to use MySQL connection to store data :
|
||||
sql_connection=mysql://ceilometer:password@192.168.42.101/ceilometer
|
||||
----
|
||||
@ -1,74 +0,0 @@
|
||||
[[s-cinder-api]]
|
||||
==== Highly available Block Storage API
|
||||
|
||||
Making the Block Storage (cinder) API service highly available in active / passive mode involves
|
||||
|
||||
* Configure Block Storage to listen on the VIP address,
|
||||
* managing Block Storage API daemon with the Pacemaker cluster manager,
|
||||
* Configure OpenStack services to use this IP address.
|
||||
|
||||
NOTE: Here is the
|
||||
http://docs.openstack.org/trunk/install-guide/install/apt/content/ch_cinder.html[documentation]
|
||||
for installing Block Storage service.
|
||||
|
||||
|
||||
===== Add Block Storage API resource to Pacemaker
|
||||
|
||||
First of all, you need to download the resource agent to your system:
|
||||
|
||||
----
|
||||
cd /usr/lib/ocf/resource.d/openstack
|
||||
wget https://raw.github.com/madkiss/openstack-resource-agents/master/ocf/cinder-api
|
||||
chmod a+rx *
|
||||
----
|
||||
|
||||
You can now add the Pacemaker configuration for
|
||||
Block Storage API resource. Connect to the Pacemaker cluster with +crm
|
||||
configure+, and add the following cluster resources:
|
||||
|
||||
----
|
||||
include::includes/pacemaker-cinder_api.crm[]
|
||||
----
|
||||
|
||||
This configuration creates
|
||||
|
||||
* +p_cinder-api+, a resource for manage Block Storage API service
|
||||
|
||||
+crm configure+ supports batch input, so you may copy and paste the
|
||||
above into your live pacemaker configuration, and then make changes as
|
||||
required. For example, you may enter +edit p_ip_cinder-api+ from the
|
||||
+crm configure+ menu and edit the resource to match your preferred
|
||||
virtual IP address.
|
||||
|
||||
Once completed, commit your configuration changes by entering +commit+
|
||||
from the +crm configure+ menu. Pacemaker will then start the Block Storage API
|
||||
service, and its dependent resources, on one of your nodes.
|
||||
|
||||
===== Configure Block Storage API service
|
||||
|
||||
Edit +/etc/cinder/cinder.conf+:
|
||||
----
|
||||
# We have to use MySQL connection to store data:
|
||||
sql_connection=mysql://cinder:password@192.168.42.101/cinder
|
||||
|
||||
# We bind Block Storage API to the VIP:
|
||||
osapi_volume_listen = 192.168.42.103
|
||||
|
||||
# We send notifications to High Available RabbitMQ:
|
||||
notifier_strategy = rabbit
|
||||
rabbit_host = 192.168.42.102
|
||||
----
|
||||
|
||||
|
||||
===== Configure OpenStack services to use highly available Block Storage API
|
||||
|
||||
Your OpenStack services must now point their Block Storage API configuration to
|
||||
the highly available, virtual cluster IP address -- rather than a
|
||||
Block Storage API server's physical IP address as you normally would.
|
||||
|
||||
You must create the Block Storage API endpoint with this IP.
|
||||
|
||||
NOTE: If you are using both private and public IP, you should create two Virtual IPs and define your endpoint like this:
|
||||
----
|
||||
keystone endpoint-create --region $KEYSTONE_REGION --service-id $service-id --publicurl 'http://PUBLIC_VIP:8776/v1/%(tenant_id)s' --adminurl 'http://192.168.42.103:8776/v1/%(tenant_id)s' --internalurl 'http://192.168.42.103:8776/v1/%(tenant_id)s'
|
||||
----
|
||||
@ -1,7 +0,0 @@
|
||||
[[ch-controller]]
|
||||
=== Cloud controller cluster stack
|
||||
|
||||
The cloud controller runs on the management network and must talk to all other services.
|
||||
|
||||
include::ap-mysql.txt[]
|
||||
include::ap-rabbitmq.txt[]
|
||||
@ -1,84 +0,0 @@
|
||||
[[s-glance-api]]
|
||||
==== Highly available OpenStack Image API
|
||||
|
||||
OpenStack Image Service offers a service for discovering, registering, and retrieving virtual machine images.
|
||||
To make the OpenStack Image API service highly available in active / passive mode, you must:
|
||||
|
||||
* Configure OpenStack Image to listen on the VIP address.
|
||||
* Manage OpenStack Image API daemon with the Pacemaker cluster manager.
|
||||
* Configure OpenStack services to use this IP address.
|
||||
|
||||
NOTE: Here is the http://docs.openstack.org/trunk/install-guide/install/apt/content/ch_installing-openstack-image.html[documentation] for installing OpenStack Image API service.
|
||||
|
||||
|
||||
===== Add OpenStack Image API resource to Pacemaker
|
||||
|
||||
First of all, you need to download the resource agent to your system:
|
||||
|
||||
----
|
||||
cd /usr/lib/ocf/resource.d/openstack
|
||||
wget https://raw.github.com/madkiss/openstack-resource-agents/master/ocf/glance-api
|
||||
chmod a+rx *
|
||||
----
|
||||
|
||||
You can now add the Pacemaker configuration for
|
||||
OpenStack Image API resource. Connect to the Pacemaker cluster with +crm
|
||||
configure+, and add the following cluster resources:
|
||||
|
||||
----
|
||||
include::includes/pacemaker-glance_api.crm[]
|
||||
----
|
||||
|
||||
This configuration creates
|
||||
|
||||
* +p_glance-api+, a resource for manage OpenStack Image API service
|
||||
|
||||
+crm configure+ supports batch input, so you may copy and paste the
|
||||
above into your live pacemaker configuration, and then make changes as
|
||||
required. For example, you may enter +edit p_ip_glance-api+ from the
|
||||
+crm configure+ menu and edit the resource to match your preferred
|
||||
virtual IP address.
|
||||
|
||||
Once completed, commit your configuration changes by entering +commit+
|
||||
from the +crm configure+ menu. Pacemaker will then start the OpenStack Image API
|
||||
service, and its dependent resources, on one of your nodes.
|
||||
|
||||
===== Configure OpenStack Image Service API
|
||||
|
||||
Edit +/etc/glance/glance-api.conf+:
|
||||
----
|
||||
# We have to use MySQL connection to store data:
|
||||
sql_connection=mysql://glance:password@192.168.42.101/glance
|
||||
|
||||
# We bind OpenStack Image API to the VIP:
|
||||
bind_host = 192.168.42.103
|
||||
|
||||
# Connect to OpenStack Image Registry service:
|
||||
registry_host = 192.168.42.103
|
||||
|
||||
# We send notifications to High Available RabbitMQ:
|
||||
notifier_strategy = rabbit
|
||||
rabbit_host = 192.168.42.102
|
||||
----
|
||||
|
||||
|
||||
===== Configure OpenStack services to use high available OpenStack Image API
|
||||
|
||||
Your OpenStack services must now point their OpenStack Image API configuration to
|
||||
the highly available, virtual cluster IP address -- rather than an
|
||||
OpenStack Image API server's physical IP address as you normally would.
|
||||
|
||||
For OpenStack Compute, for example, if your OpenStack Image API service IP address is
|
||||
192.168.42.104 as in the configuration explained here, you would use
|
||||
the following line in your +nova.conf+ file:
|
||||
|
||||
----
|
||||
glance_api_servers = 192.168.42.103
|
||||
----
|
||||
|
||||
You must also create the OpenStack Image API endpoint with this IP.
|
||||
|
||||
NOTE: If you are using both private and public IP addresses, you should create two Virtual IP addresses and define your endpoint like this:
|
||||
----
|
||||
keystone endpoint-create --region $KEYSTONE_REGION --service-id $service-id --publicurl 'http://PUBLIC_VIP:9292' --adminurl 'http://192.168.42.103:9292' --internalurl 'http://192.168.42.103:9292'
|
||||
----
|
||||
@ -1,97 +0,0 @@
|
||||
[[s-keystone]]
|
||||
==== Highly available OpenStack Identity
|
||||
|
||||
OpenStack Identity is the Identity Service in OpenStack and used by many services.
|
||||
Making the OpenStack Identity service highly available in active / passive mode involves
|
||||
|
||||
* Configure OpenStack Identity to listen on the VIP address,
|
||||
* managing OpenStack Identity daemon with the Pacemaker cluster manager,
|
||||
* Configure OpenStack services to use this IP address.
|
||||
|
||||
NOTE: Here is the http://docs.openstack.org/trunk/install-guide/install/apt/content/ch_installing-openstack-identity-service.html[documentation] for installing OpenStack Identity service.
|
||||
|
||||
|
||||
===== Add OpenStack Identity resource to Pacemaker
|
||||
|
||||
First of all, you need to download the resource agent to your system:
|
||||
|
||||
----
|
||||
cd /usr/lib/ocf/resource.d
|
||||
mkdir openstack
|
||||
cd openstack
|
||||
wget https://raw.github.com/madkiss/openstack-resource-agents/master/ocf/keystone
|
||||
chmod a+rx *
|
||||
----
|
||||
|
||||
You can now add the Pacemaker configuration for
|
||||
OpenStack Identity resource. Connect to the Pacemaker cluster with +crm
|
||||
configure+, and add the following cluster resources:
|
||||
|
||||
----
|
||||
include::includes/pacemaker-keystone.crm[]
|
||||
----
|
||||
|
||||
This configuration creates +p_keystone+, a resource for managing the OpenStack Identity service.
|
||||
|
||||
+crm configure+ supports batch input, so you may copy and paste the
|
||||
above into your live pacemaker configuration, and then make changes as
|
||||
required. For example, you may enter +edit p_ip_keystone+ from the
|
||||
+crm configure+ menu and edit the resource to match your preferred
|
||||
virtual IP address.
|
||||
|
||||
Once completed, commit your configuration changes by entering +commit+
|
||||
from the +crm configure+ menu. Pacemaker will then start the OpenStack Identity
|
||||
service, and its dependent resources, on one of your nodes.
|
||||
|
||||
===== Configure OpenStack Identity service
|
||||
|
||||
You need to edit your OpenStack Identity configuration file (+keystone.conf+) and change the bind parameters:
|
||||
|
||||
On Havana:
|
||||
----
|
||||
bind_host = 192.168.42.103
|
||||
----
|
||||
|
||||
On Icehouse, the +admin_bind_host+ option lets you use a private network for the admin access.
|
||||
----
|
||||
public_bind_host = 192.168.42.103
|
||||
admin_bind_host = 192.168.42.103
|
||||
----
|
||||
|
||||
To be sure all data will be highly available, you should be sure that you store everything in the MySQL database (which is also highly available):
|
||||
----
|
||||
[catalog]
|
||||
driver = keystone.catalog.backends.sql.Catalog
|
||||
...
|
||||
[identity]
|
||||
driver = keystone.identity.backends.sql.Identity
|
||||
...
|
||||
----
|
||||
|
||||
|
||||
===== Configure OpenStack services to use the highly available OpenStack Identity
|
||||
|
||||
Your OpenStack services must now point their OpenStack Identity configuration to
|
||||
the highly available, virtual cluster IP address -- rather than a
|
||||
OpenStack Identity server's physical IP address as you normally would.
|
||||
|
||||
For example with OpenStack Compute, if your OpenStack Identity service IP address is
|
||||
192.168.42.103 as in the configuration explained here, you would use
|
||||
the following line in your API configuration file
|
||||
(+api-paste.ini+):
|
||||
|
||||
----
|
||||
auth_host = 192.168.42.103
|
||||
----
|
||||
|
||||
You also need to create the OpenStack Identity Endpoint with this IP.
|
||||
|
||||
NOTE : If you are using both private and public IP addresses, you should create two Virtual IP addresses and define your endpoint like this:
|
||||
----
|
||||
keystone endpoint-create --region $KEYSTONE_REGION --service-id $service-id --publicurl 'http://PUBLIC_VIP:5000/v2.0' --adminurl 'http://192.168.42.103:35357/v2.0' --internalurl 'http://192.168.42.103:5000/v2.0'
|
||||
----
|
||||
|
||||
If you are using the horizon dashboard, you should edit the +local_settings.py+ file:
|
||||
----
|
||||
OPENSTACK_HOST = 192.168.42.103
|
||||
----
|
||||
@ -1,177 +0,0 @@
|
||||
[[s-mysql]]
|
||||
==== Highly available MySQL
|
||||
|
||||
MySQL is the default database server used by many OpenStack
|
||||
services. Making the MySQL service highly available involves
|
||||
|
||||
* Configure a DRBD device for use by MySQL,
|
||||
* Configure MySQL to use a data directory residing on that DRBD
|
||||
device,
|
||||
* selecting and assigning a virtual IP address (VIP) that can freely
|
||||
float between cluster nodes,
|
||||
* Configure MySQL to listen on that IP address,
|
||||
* managing all resources, including the MySQL daemon itself, with
|
||||
the Pacemaker cluster manager.
|
||||
|
||||
NOTE: http://codership.com/products/mysql_galera[MySQL/Galera] is an
|
||||
alternative method of Configure MySQL for high availability. It is
|
||||
likely to become the preferred method of achieving MySQL high
|
||||
availability once it has sufficiently matured. At the time of writing,
|
||||
however, the Pacemaker/DRBD based approach remains the recommended one
|
||||
for OpenStack environments.
|
||||
|
||||
===== Configure DRBD
|
||||
|
||||
The Pacemaker based MySQL server requires a DRBD resource from
|
||||
which it mounts the +/var/lib/mysql+ directory. In this example,
|
||||
the DRBD resource is simply named +mysql+:
|
||||
|
||||
.+mysql+ DRBD resource configuration (+/etc/drbd.d/mysql.res+)
|
||||
----
|
||||
include::includes/mysql.res[]
|
||||
----
|
||||
|
||||
This resource uses an underlying local disk (in DRBD terminology, a
|
||||
_backing device_) named +/dev/data/mysql+ on both cluster nodes,
|
||||
+node1+ and +node2+. Normally, this would be an LVM Logical Volume
|
||||
specifically set aside for this purpose. The DRBD +meta-disk+ is
|
||||
+internal+, meaning DRBD-specific metadata is being stored at the end
|
||||
of the +disk+ device itself. The device is configured to communicate
|
||||
between IPv4 addresses 10.0.42.100 and 10.0.42.254, using TCP port
|
||||
7700. Once enabled, it will map to a local DRBD block device with the
|
||||
device minor number 0, that is, +/dev/drbd0+.
|
||||
|
||||
Enabling a DRBD resource is explained in detail in
|
||||
http://www.drbd.org/users-guide-8.3/s-first-time-up.html[the DRBD
|
||||
User's Guide]. In brief, the proper sequence of commands is this:
|
||||
|
||||
----
|
||||
drbdadm create-md mysql <1>
|
||||
drbdadm up mysql <2>
|
||||
drbdadm -- --force primary mysql <3>
|
||||
----
|
||||
|
||||
<1> Initializes DRBD metadata and writes the initial set of metadata
|
||||
to +/dev/data/mysql+. Must be completed on both nodes.
|
||||
|
||||
<2> Creates the +/dev/drbd0+ device node, _attaches_ the DRBD device
|
||||
to its backing store, and _connects_ the DRBD node to its peer. Must
|
||||
be completed on both nodes.
|
||||
|
||||
<3> Kicks off the initial device synchronization, and puts the device
|
||||
into the +primary+ (readable and writable) role. See
|
||||
http://www.drbd.org/users-guide-8.3/ch-admin.html#s-roles[Resource
|
||||
roles] (from the DRBD User's Guide) for a more detailed description of
|
||||
the primary and secondary roles in DRBD. Must be completed _on one
|
||||
node only,_ namely the one where you are about to continue with
|
||||
creating your filesystem.
|
||||
|
||||
===== Creating a file system
|
||||
|
||||
Once the DRBD resource is running and in the primary role (and
|
||||
potentially still in the process of running the initial device
|
||||
synchronization), you may proceed with creating the filesystem for
|
||||
MySQL data. XFS is the generally recommended filesystem:
|
||||
|
||||
----
|
||||
mkfs -t xfs /dev/drbd0
|
||||
----
|
||||
|
||||
You may also use the alternate device path for the DRBD device, which
|
||||
may be easier to remember as it includes the self-explanatory resource
|
||||
name:
|
||||
|
||||
----
|
||||
mkfs -t xfs /dev/drbd/by-res/mysql
|
||||
----
|
||||
|
||||
Once completed, you may safely return the device to the secondary
|
||||
role. Any ongoing device synchronization will continue in the
|
||||
background:
|
||||
|
||||
----
|
||||
drbdadm secondary mysql
|
||||
----
|
||||
|
||||
===== Prepare MySQL for Pacemaker high availability
|
||||
|
||||
In order for Pacemaker monitoring to function properly, you must
|
||||
ensure that MySQL's database files reside on the DRBD device. If you
|
||||
already have an existing MySQL database, the simplest approach is to
|
||||
just move the contents of the existing +/var/lib/mysql+ directory into
|
||||
the newly created filesystem on the DRBD device.
|
||||
|
||||
WARNING: You must complete the next step while the MySQL database
|
||||
server is shut down.
|
||||
|
||||
----
|
||||
node1:# mount /dev/drbd/by-res/mysql /mnt
|
||||
node1:# mv /var/lib/mysql/* /mnt
|
||||
node1:# umount /mnt
|
||||
----
|
||||
|
||||
For a new MySQL installation with no existing data, you may also run
|
||||
the +mysql_install_db+ command:
|
||||
|
||||
----
|
||||
node1:# mount /dev/drbd/by-res/mysql /mnt
|
||||
node1:# mysql_install_db --datadir=/mnt
|
||||
node1:# umount /mnt
|
||||
----
|
||||
|
||||
Regardless of the approach, the steps outlined here must be completed
|
||||
on only one cluster node.
|
||||
|
||||
===== Add MySQL resources to Pacemaker
|
||||
|
||||
You can now add the Pacemaker configuration for
|
||||
MySQL resources. Connect to the Pacemaker cluster with +crm
|
||||
configure+, and add the following cluster resources:
|
||||
|
||||
----
|
||||
include::includes/pacemaker-mysql.crm[]
|
||||
----
|
||||
|
||||
This configuration creates
|
||||
|
||||
* +p_ip_mysql+, a virtual IP address for use by MySQL
|
||||
(192.168.42.101),
|
||||
* +p_fs_mysql+, a Pacemaker managed filesystem mounted to
|
||||
+/var/lib/mysql+ on whatever node currently runs the MySQL
|
||||
service,
|
||||
* +ms_drbd_mysql+, the _master/slave set_ managing the +mysql+
|
||||
DRBD resource,
|
||||
* a service +group+ and +order+ and +colocation+ constraints to ensure
|
||||
resources are started on the correct nodes, and in the correct sequence.
|
||||
|
||||
+crm configure+ supports batch input, so you may copy and paste the
|
||||
above into your live pacemaker configuration, and then make changes as
|
||||
required. For example, you may enter +edit p_ip_mysql+ from the
|
||||
+crm configure+ menu and edit the resource to match your preferred
|
||||
virtual IP address.
|
||||
|
||||
Once completed, commit your configuration changes by entering +commit+
|
||||
from the +crm configure+ menu. Pacemaker will then start the MySQL
|
||||
service, and its dependent resources, on one of your nodes.
|
||||
|
||||
===== Configure OpenStack services for highly available MySQL
|
||||
|
||||
Your OpenStack services must now point their MySQL configuration to
|
||||
the highly available, virtual cluster IP address -- rather than a
|
||||
MySQL server's physical IP address as you normally would.
|
||||
|
||||
For OpenStack Image, for example, if your MySQL service IP address is
|
||||
192.168.42.101 as in the configuration explained here, you would use
|
||||
the following line in your OpenStack Image registry configuration file
|
||||
(+glance-registry.conf+):
|
||||
|
||||
----
|
||||
sql_connection = mysql://glancedbadmin:<password>@192.168.42.101/glance
|
||||
----
|
||||
|
||||
No other changes are necessary to your OpenStack configuration. If the
|
||||
node currently hosting your database experiences a problem
|
||||
necessitating service failover, your OpenStack services may experience
|
||||
a brief MySQL interruption, as they would in the event of a network
|
||||
hiccup, and then continue to run normally.
|
||||
|
||||
@ -1,139 +0,0 @@
|
||||
[[ch-network]]
|
||||
=== Network controller cluster stack
|
||||
|
||||
The network controller sits on the management and data network, and needs to be connected to the Internet if a VM needs access to it.
|
||||
|
||||
NOTE: Both nodes should have the same hostname since the Networking scheduler will be
|
||||
aware of one node, for example a virtual router attached to a single L3 node.
|
||||
|
||||
==== Highly available neutron L3 agent
|
||||
|
||||
The neutron L3 agent provides L3/NAT forwarding to ensure external network access
|
||||
for VMs on tenant networks. High availability for the L3 agent is achieved by
|
||||
adopting Pacemaker.
|
||||
|
||||
NOTE: Here is the http://docs.openstack.org/trunk/config-reference/content/section_adv_cfg_l3_agent.html[documentation] for installing neutron L3 agent.
|
||||
|
||||
|
||||
===== Add neutron L3 agent resource to Pacemaker
|
||||
First of all, you need to download the resource agent to your system:
|
||||
|
||||
----
|
||||
cd /usr/lib/ocf/resource.d/openstack
|
||||
wget https://raw.github.com/madkiss/openstack-resource-agents/master/ocf/neutron-agent-l3
|
||||
chmod a+rx neutron-l3-agent
|
||||
----
|
||||
|
||||
You may now proceed with adding the Pacemaker configuration for
|
||||
neutron L3 agent resource. Connect to the Pacemaker cluster with +crm
|
||||
configure+, and add the following cluster resources:
|
||||
|
||||
----
|
||||
include::includes/pacemaker-network-l3.crm[]
|
||||
----
|
||||
|
||||
This configuration creates
|
||||
|
||||
* +p_neutron-l3-agent+, a resource for manage Neutron L3 Agent service
|
||||
|
||||
+crm configure+ supports batch input, so you may copy and paste the
|
||||
above into your live pacemaker configuration, and then make changes as
|
||||
required.
|
||||
|
||||
Once completed, commit your configuration changes by entering +commit+
|
||||
from the +crm configure+ menu. Pacemaker will then start the neutron L3 agent
|
||||
service, and its dependent resources, on one of your nodes.
|
||||
|
||||
NOTE: This method does not ensure a zero downtime since it has to recreate all
|
||||
the namespaces and virtual routers on the node.
|
||||
|
||||
|
||||
==== Highly available neutron DHCP agent
|
||||
|
||||
Neutron DHCP agent distributes IP addresses to the VMs with dnsmasq (by
|
||||
default). High availability for the DHCP agent is achieved by adopting
|
||||
Pacemaker.
|
||||
|
||||
NOTE: Here is the http://docs.openstack.org/trunk/config-reference/content/section_adv_cfg_dhcp_agent.html[documentation] for installing neutron DHCP agent.
|
||||
|
||||
|
||||
===== Add neutron DHCP agent resource to Pacemaker
|
||||
First of all, you need to download the resource agent to your system:
|
||||
|
||||
----
|
||||
cd /usr/lib/ocf/resource.d/openstack
|
||||
wget https://raw.github.com/madkiss/openstack-resource-agents/master/ocf/neutron-agent-dhcp
|
||||
chmod a+rx neutron-dhcp-agent
|
||||
----
|
||||
|
||||
You may now proceed with adding the Pacemaker configuration for
|
||||
neutron DHCP agent resource. Connect to the Pacemaker cluster with +crm
|
||||
configure+, and add the following cluster resources:
|
||||
|
||||
----
|
||||
include::includes/pacemaker-network-dhcp.crm[]
|
||||
----
|
||||
|
||||
This configuration creates
|
||||
|
||||
* +p_neutron-dhcp-agent+, a resource for manage Neutron DHCP Agent
|
||||
service
|
||||
|
||||
+crm configure+ supports batch input, so you may copy and paste the
|
||||
above into your live pacemaker configuration, and then make changes as
|
||||
required.
|
||||
|
||||
Once completed, commit your configuration changes by entering +commit+
|
||||
from the +crm configure+ menu. Pacemaker will then start the neutron DHCP
|
||||
agent service, and its dependent resources, on one of your nodes.
|
||||
|
||||
|
||||
==== Highly available neutron metadata agent
|
||||
|
||||
Neutron metadata agent allows Compute API metadata to be reachable by VMs on tenant
|
||||
networks. High availability for the metadata agent is achieved by adopting
|
||||
Pacemaker.
|
||||
|
||||
NOTE: Here is the http://docs.openstack.org/trunk/config-reference/content/networking-options-metadata.html[documentation] for installing Neutron Metadata Agent.
|
||||
|
||||
|
||||
===== Add neutron metadata agent resource to Pacemaker
|
||||
First of all, you need to download the resource agent to your system:
|
||||
|
||||
----
|
||||
cd /usr/lib/ocf/resource.d/openstack
|
||||
wget https://raw.github.com/madkiss/openstack-resource-agents/master/ocf/neutron-metadata-agent
|
||||
chmod a+rx neutron-metadata-agent
|
||||
----
|
||||
|
||||
You may now proceed with adding the Pacemaker configuration for
|
||||
neutron metadata agent resource. Connect to the Pacemaker cluster with +crm
|
||||
configure+, and add the following cluster resources:
|
||||
|
||||
----
|
||||
include::includes/pacemaker-network-metadata.crm[]
|
||||
----
|
||||
|
||||
This configuration creates
|
||||
|
||||
* +p_neutron-metadata-agent+, a resource for manage Neutron Metadata Agent
|
||||
service
|
||||
|
||||
+crm configure+ supports batch input, so you may copy and paste the
|
||||
above into your live pacemaker configuration, and then make changes as
|
||||
required.
|
||||
|
||||
Once completed, commit your configuration changes by entering +commit+
|
||||
from the +crm configure+ menu. Pacemaker will then start the neutron metadata
|
||||
agent service, and its dependent resources, on one of your nodes.
|
||||
|
||||
|
||||
==== Manage network resources
|
||||
You can now add the Pacemaker configuration for
|
||||
managing all network resources together with a group.
|
||||
Connect to the Pacemaker cluster with +crm configure+, and add the following
|
||||
cluster resources:
|
||||
|
||||
----
|
||||
include::includes/pacemaker-network.crm[]
|
||||
----
|
||||
@ -1,78 +0,0 @@
|
||||
[[s-neutron-server]]
|
||||
==== Highly available OpenStack Networking server
|
||||
|
||||
OpenStack Networking is the network connectivity service in OpenStack.
|
||||
Making the OpenStack Networking Server service highly available in active / passive mode involves
|
||||
|
||||
* Configure OpenStack Networking to listen on the VIP address,
|
||||
* managing OpenStack Networking API Server daemon with the Pacemaker cluster manager,
|
||||
* Configure OpenStack services to use this IP address.
|
||||
|
||||
NOTE: Here is the http://docs.openstack.org/trunk/install-guide/install/apt/content/ch_installing-openstack-networking.html[documentation] for installing OpenStack Networking service.
|
||||
|
||||
|
||||
===== Add OpenStack Networking Server resource to Pacemaker
|
||||
|
||||
First of all, you need to download the resource agent to your system:
|
||||
----
|
||||
cd /usr/lib/ocf/resource.d/openstack
|
||||
wget https://raw.github.com/madkiss/openstack-resource-agents/master/ocf/neutron-server
|
||||
chmod a+rx *
|
||||
----
|
||||
|
||||
You can now add the Pacemaker configuration for
|
||||
OpenStack Networking Server resource. Connect to the Pacemaker cluster with +crm
|
||||
configure+, and add the following cluster resources:
|
||||
----
|
||||
include::includes/pacemaker-neutron_server.crm[]
|
||||
----
|
||||
|
||||
This configuration creates +p_neutron-server+, a resource for manage OpenStack Networking Server service
|
||||
|
||||
+crm configure+ supports batch input, so you may copy and paste the
|
||||
above into your live pacemaker configuration, and then make changes as
|
||||
required. For example, you may enter +edit p_neutron-server+ from the
|
||||
+crm configure+ menu and edit the resource to match your preferred
|
||||
virtual IP address.
|
||||
|
||||
Once completed, commit your configuration changes by entering +commit+
|
||||
from the +crm configure+ menu. Pacemaker will then start the OpenStack Networking API
|
||||
service, and its dependent resources, on one of your nodes.
|
||||
|
||||
===== Configure OpenStack Networking server
|
||||
|
||||
Edit +/etc/neutron/neutron.conf+ :
|
||||
----
|
||||
# We bind the service to the VIP:
|
||||
bind_host = 192.168.42.103
|
||||
|
||||
# We bind OpenStack Networking Server to the VIP:
|
||||
bind_host = 192.168.42.103
|
||||
|
||||
# We send notifications to Highly available RabbitMQ:
|
||||
notifier_strategy = rabbit
|
||||
rabbit_host = 192.168.42.102
|
||||
|
||||
[database]
|
||||
# We have to use MySQL connection to store data:
|
||||
connection = mysql://neutron:password@192.168.42.101/neutron
|
||||
----
|
||||
|
||||
|
||||
===== Configure OpenStack services to use highly available OpenStack Networking server
|
||||
|
||||
Your OpenStack services must now point their OpenStack Networking Server configuration to
|
||||
the highly available, virtual cluster IP address -- rather than an
|
||||
OpenStack Networking server's physical IP address as you normally would.
|
||||
|
||||
For example, you should configure OpenStack Compute for using highly available OpenStack Networking server in editing +nova.conf+ file:
|
||||
----
|
||||
neutron_url = http://192.168.42.103:9696
|
||||
----
|
||||
|
||||
You need to create the OpenStack Networking server endpoint with this IP.
|
||||
|
||||
NOTE: If you are using both private and public IP addresses, you should create two Virtual IP addresses and define your endpoint like this:
|
||||
----
|
||||
keystone endpoint-create --region $KEYSTONE_REGION --service-id $service-id --publicurl 'http://PUBLIC_VIP:9696/' --adminurl 'http://192.168.42.103:9696/' --internalurl 'http://192.168.42.103:9696/'
|
||||
----
|
||||
@ -1,2 +0,0 @@
|
||||
[[ha-using-active-passive]]
|
||||
== HA using active/passive
|
||||
@ -1,210 +0,0 @@
|
||||
[[ch-pacemaker]]
|
||||
=== The Pacemaker cluster stack
|
||||
|
||||
OpenStack infrastructure high availability relies on the
|
||||
http://www.clusterlabs.org[Pacemaker] cluster stack, the
|
||||
state-of-the-art high availability and load balancing stack for the
|
||||
Linux platform. Pacemaker is storage and application-agnostic, and is
|
||||
in no way specific to OpenStack.
|
||||
|
||||
Pacemaker relies on the http://www.corosync.org[Corosync] messaging
|
||||
layer for reliable cluster communications. Corosync implements the
|
||||
Totem single-ring ordering and membership protocol. It also provides UDP
|
||||
and InfiniBand based messaging, quorum, and cluster membership to
|
||||
Pacemaker.
|
||||
|
||||
Pacemaker interacts with applications through _resource agents_ (RAs),
|
||||
of which it supports over 70 natively. Pacemaker can also easily use
|
||||
third-party RAs. An OpenStack high-availability configuration uses
|
||||
existing native Pacemaker RAs (such as those managing MySQL
|
||||
databases or virtual IP addresses), existing third-party RAs (such as
|
||||
for RabbitMQ), and native OpenStack RAs (such as those managing the
|
||||
OpenStack Identity and Image Services).
|
||||
|
||||
==== Install packages
|
||||
|
||||
On any host that is meant to be part of a Pacemaker cluster, you must
|
||||
first establish cluster communications through the Corosync messaging
|
||||
layer. This involves Install the following packages (and their
|
||||
dependencies, which your package manager will normally install
|
||||
automatically):
|
||||
|
||||
* +pacemaker+ Note that the crm shell should be downloaded separately.
|
||||
* +crmsh+
|
||||
* +corosync+
|
||||
* +cluster-glue+
|
||||
* +fence-agents+ (Fedora only; all other distributions use fencing
|
||||
agents from +cluster-glue+)
|
||||
* +resource-agents+
|
||||
|
||||
==== Set up Corosync
|
||||
|
||||
Besides installing the +corosync+ package, you must also
|
||||
create a configuration file, stored in
|
||||
+/etc/corosync/corosync.conf+. Most distributions ship an example
|
||||
configuration file (+corosync.conf.example+) as part of the
|
||||
documentation bundled with the +corosync+ package. An example Corosync
|
||||
configuration file is shown below:
|
||||
|
||||
.Corosync configuration file (+corosync.conf+)
|
||||
----
|
||||
include::includes/corosync.conf[]
|
||||
----
|
||||
|
||||
<1> The +token+ value specifies the time, in milliseconds, during
|
||||
which the Corosync token is expected to be transmitted around the
|
||||
ring. When this timeout expires, the token is declared lost, and after
|
||||
+token_retransmits_before_loss_const+ lost tokens the non-responding
|
||||
_processor_ (cluster node) is declared dead. In other words,
|
||||
+token+ × +token_retransmits_before_loss_const+ is the maximum
|
||||
time a node is allowed to not respond to cluster messages before being
|
||||
considered dead. The default for +token+ is 1000 (1 second), with 4
|
||||
allowed retransmits. These defaults are intended to minimize failover
|
||||
times, but can cause frequent "false alarms" and unintended failovers
|
||||
in case of short network interruptions. The values used here are
|
||||
safer, albeit with slightly extended failover times.
|
||||
|
||||
<2> With +secauth+ enabled, Corosync nodes mutually authenticate using
|
||||
a 128-byte shared secret stored in +/etc/corosync/authkey+, which may
|
||||
be generated with the +corosync-keygen+ utility. When using +secauth+,
|
||||
cluster communications are also encrypted.
|
||||
|
||||
<3> In Corosync configurations using redundant networking (with more
|
||||
than one +interface+), you must select a Redundant Ring Protocol (RRP)
|
||||
mode other than +none+. +active+ is the recommended RRP mode.
|
||||
|
||||
<4> There are several things to note about the recommended interface
|
||||
configuration:
|
||||
* The +ringnumber+ must differ between all configured interfaces,
|
||||
starting with 0.
|
||||
* The +bindnetaddr+ is the _network_ address of the interfaces to bind
|
||||
to. The example uses two network addresses of +/24+ IPv4 subnets.
|
||||
* Multicast groups (+mcastaddr+) _must not_ be reused across cluster
|
||||
boundaries. In other words, no two distinct clusters should ever use
|
||||
the same multicast group. Be sure to select multicast addresses
|
||||
compliant with http://www.ietf.org/rfc/rfc2365.txt[RFC 2365,
|
||||
"Administratively Scoped IP Multicast"].
|
||||
* For firewall configurations, note that Corosync communicates over
|
||||
UDP only, and uses +mcastport+ (for receives) and +mcastport+-1 (for
|
||||
sends).
|
||||
|
||||
<5> The +service+ declaration for the +pacemaker+ service may be
|
||||
placed in the +corosync.conf+ file directly, or in its own separate
|
||||
file, +/etc/corosync/service.d/pacemaker+.
|
||||
|
||||
Once created, the +corosync.conf+ file (and the +authkey+ file if the
|
||||
+secauth+ option is enabled) must be synchronized across all cluster
|
||||
nodes.
|
||||
|
||||
==== Starting Corosync
|
||||
|
||||
Corosync is started as a regular system service. Depending on your
|
||||
distribution, it may ship with a LSB (System V style) init script, an
|
||||
upstart job, or a systemd unit file. Either way, the service is
|
||||
usually named +corosync+:
|
||||
|
||||
* +/etc/init.d/corosync start+ (LSB)
|
||||
* +service corosync start+ (LSB, alternate)
|
||||
* +start corosync+ (upstart)
|
||||
* +systemctl start corosync+ (systemd)
|
||||
|
||||
You can now check the Corosync connectivity with two tools.
|
||||
|
||||
The +corosync-cfgtool+ utility, when invoked with the +-s+ option,
|
||||
gives a summary of the health of the communication rings:
|
||||
|
||||
----
|
||||
# corosync-cfgtool -s
|
||||
Printing ring status.
|
||||
Local node ID 435324542
|
||||
RING ID 0
|
||||
id = 192.168.42.82
|
||||
status = ring 0 active with no faults
|
||||
RING ID 1
|
||||
id = 10.0.42.100
|
||||
status = ring 1 active with no faults
|
||||
----
|
||||
|
||||
The +corosync-objctl+ utility can be used to dump the Corosync cluster
|
||||
member list:
|
||||
|
||||
----
|
||||
# corosync-objctl runtime.totem.pg.mrp.srp.members
|
||||
runtime.totem.pg.mrp.srp.435324542.ip=r(0) ip(192.168.42.82) r(1) ip(10.0.42.100)
|
||||
runtime.totem.pg.mrp.srp.435324542.join_count=1
|
||||
runtime.totem.pg.mrp.srp.435324542.status=joined
|
||||
runtime.totem.pg.mrp.srp.983895584.ip=r(0) ip(192.168.42.87) r(1) ip(10.0.42.254)
|
||||
runtime.totem.pg.mrp.srp.983895584.join_count=1
|
||||
runtime.totem.pg.mrp.srp.983895584.status=joined
|
||||
----
|
||||
|
||||
You should see a +status=joined+ entry for each of your constituent
|
||||
cluster nodes.
|
||||
|
||||
==== Start Pacemaker
|
||||
|
||||
Once the Corosync services have been started, and you have established
|
||||
that the cluster is communicating properly, it is safe to start
|
||||
+pacemakerd+, the Pacemaker master control process:
|
||||
|
||||
* +/etc/init.d/pacemaker start+ (LSB)
|
||||
* +service pacemaker start+ (LSB, alternate)
|
||||
* +start pacemaker+ (upstart)
|
||||
* +systemctl start pacemaker+ (systemd)
|
||||
|
||||
Once Pacemaker services have started, Pacemaker will create a default
|
||||
empty cluster configuration with no resources. You may observe
|
||||
Pacemaker's status with the +crm_mon+ utility:
|
||||
|
||||
----
|
||||
============
|
||||
Last updated: Sun Oct 7 21:07:52 2012
|
||||
Last change: Sun Oct 7 20:46:00 2012 via cibadmin on node2
|
||||
Stack: openais
|
||||
Current DC: node2 - partition with quorum
|
||||
Version: 1.1.6-9971ebba4494012a93c03b40a2c58ec0eb60f50c
|
||||
2 Nodes configured, 2 expected votes
|
||||
0 Resources configured.
|
||||
============
|
||||
|
||||
Online: [ node2 node1 ]
|
||||
----
|
||||
|
||||
==== Set basic cluster properties
|
||||
|
||||
Once your Pacemaker cluster is set up, it is recommended to set a few
|
||||
basic cluster properties. To do so, start the +crm+ shell and change
|
||||
into the configuration menu by entering
|
||||
+configure+. Alternatively. you may jump straight into the Pacemaker
|
||||
configuration menu by typing +crm configure+ directly from a shell
|
||||
prompt.
|
||||
|
||||
Then, set the following properties:
|
||||
|
||||
----
|
||||
include::includes/pacemaker-properties.crm[]
|
||||
----
|
||||
|
||||
<1> Setting +no-quorum-policy="ignore"+ is required in 2-node Pacemaker
|
||||
clusters for the following reason: if quorum enforcement is enabled,
|
||||
and one of the two nodes fails, then the remaining node can not
|
||||
establish a _majority_ of quorum votes necessary to run services, and
|
||||
thus it is unable to take over any resources. The appropriate
|
||||
workaround is to ignore loss of quorum in the cluster. This is safe
|
||||
and necessary _only_ in 2-node clusters. Do not set this property in
|
||||
Pacemaker clusters with more than two nodes.
|
||||
|
||||
<2> Setting +pe-warn-series-max+, +pe-input-series-max+ and
|
||||
+pe-error-series-max+ to 1000 instructs Pacemaker to keep a longer
|
||||
history of the inputs processed, and errors and warnings generated, by
|
||||
its Policy Engine. This history is typically useful in case cluster
|
||||
troubleshooting becomes necessary.
|
||||
|
||||
<3> Pacemaker uses an event-driven approach to cluster state
|
||||
processing. However, certain Pacemaker actions occur at a configurable
|
||||
interval, +cluster-recheck-interval+, which defaults to 15 minutes. It
|
||||
is usually prudent to reduce this to a shorter interval, such as 5 or
|
||||
3 minutes.
|
||||
|
||||
Once you have made these changes, you may +commit+ the updated
|
||||
configuration.
|
||||
@ -1,167 +0,0 @@
|
||||
[[s-rabbitmq]]
|
||||
==== Highly available RabbitMQ
|
||||
|
||||
RabbitMQ is the default AMQP server used by many OpenStack
|
||||
services. Making the RabbitMQ service highly available involves:
|
||||
|
||||
* configuring a DRBD device for use by RabbitMQ,
|
||||
* configuring RabbitMQ to use a data directory residing on that DRBD
|
||||
device,
|
||||
* selecting and assigning a virtual IP address (VIP) that can freely
|
||||
float between cluster nodes,
|
||||
* configuring RabbitMQ to listen on that IP address,
|
||||
* managing all resources, including the RabbitMQ daemon itself, with
|
||||
the Pacemaker cluster manager.
|
||||
|
||||
NOTE: There is an alternative method of configuring RabbitMQ for high
|
||||
availability. That approach, known as
|
||||
http://www.rabbitmq.com/ha.html[active-active mirrored queues],
|
||||
happens to be the one preferred by the RabbitMQ developers -- however
|
||||
it has shown less than ideal consistency and reliability in OpenStack
|
||||
clusters. Thus, at the time of writing, the Pacemaker/DRBD based
|
||||
approach remains the recommended one for OpenStack environments,
|
||||
although this may change in the near future as RabbitMQ active-active
|
||||
mirrored queues mature.
|
||||
|
||||
===== Configure DRBD
|
||||
|
||||
The Pacemaker based RabbitMQ server requires a DRBD resource from
|
||||
which it mounts the +/var/lib/rabbitmq+ directory. In this example,
|
||||
the DRBD resource is simply named +rabbitmq+:
|
||||
|
||||
.+rabbitmq+ DRBD resource configuration (+/etc/drbd.d/rabbitmq.res+)
|
||||
----
|
||||
include::includes/rabbitmq.res[]
|
||||
----
|
||||
|
||||
This resource uses an underlying local disk (in DRBD terminology, a
|
||||
_backing device_) named +/dev/data/rabbitmq+ on both cluster nodes,
|
||||
+node1+ and +node2+. Normally, this would be an LVM Logical Volume
|
||||
specifically set aside for this purpose. The DRBD +meta-disk+ is
|
||||
+internal+, meaning DRBD-specific metadata is being stored at the end
|
||||
of the +disk+ device itself. The device is configured to communicate
|
||||
between IPv4 addresses 10.0.42.100 and 10.0.42.254, using TCP port
|
||||
7701. Once enabled, it will map to a local DRBD block device with the
|
||||
device minor number 1, that is, +/dev/drbd1+.
|
||||
|
||||
Enabling a DRBD resource is explained in detail in
|
||||
http://www.drbd.org/users-guide-8.3/s-first-time-up.html[the DRBD
|
||||
User's Guide]. In brief, the proper sequence of commands is this:
|
||||
|
||||
----
|
||||
drbdadm create-md rabbitmq <1>
|
||||
drbdadm up rabbitmq <2>
|
||||
drbdadm -- --force primary rabbitmq <3>
|
||||
----
|
||||
|
||||
<1> Initializes DRBD metadata and writes the initial set of metadata
|
||||
to +/dev/data/rabbitmq+. Must be completed on both nodes.
|
||||
|
||||
<2> Creates the +/dev/drbd1+ device node, _attaches_ the DRBD device
|
||||
to its backing store, and _connects_ the DRBD node to its peer. Must
|
||||
be completed on both nodes.
|
||||
|
||||
<3> Kicks off the initial device synchronization, and puts the device
|
||||
into the +primary+ (readable and writable) role. See
|
||||
http://www.drbd.org/users-guide-8.3/ch-admin.html#s-roles[Resource
|
||||
roles] (from the DRBD User's Guide) for a more detailed description of
|
||||
the primary and secondary roles in DRBD. Must be completed _on one
|
||||
node only,_ namely the one where you are about to continue with
|
||||
creating your filesystem.
|
||||
|
||||
===== Create a file system
|
||||
|
||||
Once the DRBD resource is running and in the primary role (and
|
||||
potentially still in the process of running the initial device
|
||||
synchronization), you may proceed with creating the filesystem for
|
||||
RabbitMQ data. XFS is generally the recommended filesystem:
|
||||
|
||||
----
|
||||
mkfs -t xfs /dev/drbd1
|
||||
----
|
||||
|
||||
You may also use the alternate device path for the DRBD device, which
|
||||
may be easier to remember as it includes the self-explanatory resource
|
||||
name:
|
||||
|
||||
----
|
||||
mkfs -t xfs /dev/drbd/by-res/rabbitmq
|
||||
----
|
||||
|
||||
Once completed, you may safely return the device to the secondary
|
||||
role. Any ongoing device synchronization will continue in the
|
||||
background:
|
||||
|
||||
----
|
||||
drbdadm secondary rabbitmq
|
||||
----
|
||||
|
||||
===== Prepare RabbitMQ for Pacemaker high availability
|
||||
|
||||
In order for Pacemaker monitoring to function properly, you must
|
||||
ensure that RabbitMQ's +.erlang.cookie+ files are identical on all
|
||||
nodes, regardless of whether DRBD is mounted there or not. The
|
||||
simplest way of doing so is to take an existing +.erlang.cookie+ from
|
||||
one of your nodes, copying it to the RabbitMQ data directory on the
|
||||
other node, and also copying it to the DRBD-backed filesystem.
|
||||
|
||||
----
|
||||
node1:# scp -a /var/lib/rabbitmq/.erlang.cookie node2:/var/lib/rabbitmq/
|
||||
node1:# mount /dev/drbd/by-res/rabbitmq /mnt
|
||||
node1:# cp -a /var/lib/rabbitmq/.erlang.cookie /mnt
|
||||
node1:# umount /mnt
|
||||
----
|
||||
|
||||
===== Add RabbitMQ resources to Pacemaker
|
||||
|
||||
You may now proceed with adding the Pacemaker configuration for
|
||||
RabbitMQ resources. Connect to the Pacemaker cluster with +crm
|
||||
configure+, and add the following cluster resources:
|
||||
|
||||
----
|
||||
include::includes/pacemaker-rabbitmq.crm[]
|
||||
----
|
||||
|
||||
This configuration creates
|
||||
|
||||
* +p_ip_rabbitmp+, a virtual IP address for use by RabbitMQ
|
||||
(192.168.42.100),
|
||||
* +p_fs_rabbitmq+, a Pacemaker managed filesystem mounted to
|
||||
+/var/lib/rabbitmq+ on whatever node currently runs the RabbitMQ
|
||||
service,
|
||||
* +ms_drbd_rabbitmq+, the _master/slave set_ managing the +rabbitmq+
|
||||
DRBD resource,
|
||||
* a service +group+ and +order+ and +colocation+ constraints to ensure
|
||||
resources are started on the correct nodes, and in the correct sequence.
|
||||
|
||||
+crm configure+ supports batch input, so you may copy and paste the
|
||||
above into your live pacemaker configuration, and then make changes as
|
||||
required. For example, you may enter +edit p_ip_rabbitmq+ from the
|
||||
+crm configure+ menu and edit the resource to match your preferred
|
||||
virtual IP address.
|
||||
|
||||
Once completed, commit your configuration changes by entering +commit+
|
||||
from the +crm configure+ menu. Pacemaker will then start the RabbitMQ
|
||||
service, and its dependent resources, on one of your nodes.
|
||||
|
||||
===== Configure OpenStack services for highly available RabbitMQ
|
||||
|
||||
Your OpenStack services must now point their RabbitMQ configuration to
|
||||
the highly available, virtual cluster IP address -- rather than a
|
||||
RabbitMQ server's physical IP address as you normally would.
|
||||
|
||||
For OpenStack Image, for example, if your RabbitMQ service IP address is
|
||||
192.168.42.100 as in the configuration explained here, you would use
|
||||
the following line in your OpenStack Image API configuration file
|
||||
(+glance-api.conf+):
|
||||
|
||||
----
|
||||
rabbit_host = 192.168.42.100
|
||||
----
|
||||
|
||||
No other changes are necessary to your OpenStack configuration. If the
|
||||
node currently hosting your RabbitMQ experiences a problem
|
||||
necessitating service failover, your OpenStack services may experience
|
||||
a brief RabbitMQ interruption, as they would in the event of a network
|
||||
hiccup, and then continue to run normally.
|
||||
|
||||
2232
doc/high-availability-guide/bk-ha-guide.xml
Normal file
2232
doc/high-availability-guide/bk-ha-guide.xml
Normal file
File diff suppressed because it is too large
Load Diff
@ -1,62 +0,0 @@
|
||||
|
||||
<author>
|
||||
<personname>
|
||||
<firstname>Florian</firstname>
|
||||
<surname>Haas</surname>
|
||||
</personname>
|
||||
<email>florian@hastexo.com</email>
|
||||
<affiliation>
|
||||
<orgname>hastexo</orgname>
|
||||
</affiliation>
|
||||
</author>
|
||||
<copyright>
|
||||
<year>2012</year>
|
||||
<year>2013</year>
|
||||
<holder>OpenStack Contributors</holder>
|
||||
</copyright>
|
||||
<releaseinfo>current</releaseinfo>
|
||||
<productname>OpenStack</productname>
|
||||
<pubdate></pubdate>
|
||||
<legalnotice role="apache2">
|
||||
<annotation>
|
||||
<remark>Copyright details are filled in by the template.</remark>
|
||||
</annotation>
|
||||
</legalnotice>
|
||||
<abstract>
|
||||
<para>This guide describes how to install,
|
||||
configure, and manage OpenStack for high availability.</para>
|
||||
</abstract>
|
||||
<revhistory>
|
||||
<revision>
|
||||
<date>2014-04-17</date>
|
||||
<revdescription>
|
||||
<itemizedlist spacing="compact">
|
||||
<listitem>
|
||||
<para>Minor cleanup of typos, otherwise no
|
||||
major revisions for Icehouse release.</para>
|
||||
</listitem>
|
||||
</itemizedlist>
|
||||
</revdescription>
|
||||
</revision>
|
||||
<revision>
|
||||
<date>2012-01-16</date>
|
||||
<revdescription>
|
||||
<itemizedlist spacing="compact">
|
||||
<listitem>
|
||||
<para>Organizes guide based on cloud controller and compute nodes.</para>
|
||||
</listitem>
|
||||
</itemizedlist>
|
||||
</revdescription>
|
||||
</revision>
|
||||
<revision>
|
||||
<date>2012-05-24</date>
|
||||
<revdescription>
|
||||
<itemizedlist spacing="compact">
|
||||
<listitem>
|
||||
<para>Begin trunk designation.</para>
|
||||
</listitem>
|
||||
</itemizedlist>
|
||||
</revdescription>
|
||||
</revision>
|
||||
</revhistory>
|
||||
|
||||
@ -1,18 +0,0 @@
|
||||
[[bk-ha-guide]]
|
||||
= OpenStack High Availability Guide
|
||||
:docinfo:
|
||||
|
||||
include::intro.txt[]
|
||||
|
||||
include::ap-overview.txt[]
|
||||
include::ap-pacemaker.txt[]
|
||||
include::ap-cloud-controller.txt[]
|
||||
include::ap-api-node.txt[]
|
||||
include::ap-network-controller.txt[]
|
||||
|
||||
include::aa-overview.txt[]
|
||||
include::aa-database.txt[]
|
||||
include::aa-rabbitmq.txt[]
|
||||
include::aa-haproxy.txt[]
|
||||
include::aa-controllers.txt[]
|
||||
include::aa-network.txt[]
|
||||
@ -1,57 +0,0 @@
|
||||
[[ch-intro]]
|
||||
== Introduction to OpenStack High Availability
|
||||
|
||||
High Availability systems seek to minimize two things:
|
||||
|
||||
* *System downtime* -- occurs when a _user-facing_ service is unavailable beyond a specified maximum amount of time, and
|
||||
* *Data loss* -- accidental deletion or destruction of data.
|
||||
|
||||
Most high availability systems guarantee protection against system downtime and data loss only in the event of a single failure. However, they are also expected to protect against cascading failures, where a single failure deteriorates into a series of consequential failures.
|
||||
|
||||
A crucial aspect of high availability is the elimination of single points of failure (SPOFs). A SPOF is an individual piece of equipment or software which will cause system downtime or data loss if it fails. In order to eliminate SPOFs, check that mechanisms exist for redundancy of:
|
||||
|
||||
* Network components, such as switches and routers
|
||||
* Applications and automatic service migration
|
||||
* Storage components
|
||||
* Facility services such as power, air conditioning, and fire protection
|
||||
|
||||
Most high availability systems will fail in the event of multiple independent (non-consequential) failures. In this case, most systems will protect data over maintaining availability.
|
||||
|
||||
High-availability systems typically achieve uptime of 99.99% or more, which roughly equates to less than an hour of cumulative downtime per year. In order to achieve this, high availability systems should keep recovery times after a failure to about one to two minutes, sometimes significantly less.
|
||||
|
||||
OpenStack currently meets such availability requirements for its own infrastructure services, meaning that an uptime of 99.99% is feasible for the OpenStack infrastructure proper. However, OpenStack _does_ _not_ guarantee 99.99% availability for individual guest instances.
|
||||
|
||||
Preventing single points of failure can depend on whether or not a service is stateless.
|
||||
|
||||
[[stateless-vs-stateful]]
|
||||
=== Stateless vs. Stateful services
|
||||
|
||||
A stateless service is one that provides a response after your request, and then requires no further attention. To make a stateless service highly available, you need to provide redundant instances and load balance them. OpenStack services that are stateless include nova-api, nova-conductor, glance-api, keystone-api, neutron-api and nova-scheduler.
|
||||
|
||||
A stateful service is one where subsequent requests to the service depend on the results of the first request. Stateful services are more difficult to manage because a single action typically involves more than one request, so simply providing additional instances and load balancing will not solve the problem. For example, if the Horizon user interface reset itself every time you went to a new page, it wouldn't be very useful. OpenStack services that are stateful include the OpenStack database and message queue.
|
||||
|
||||
Making stateful services highly available can depend on whether you choose an active/passive or active/active configuration.
|
||||
|
||||
[[ap-intro]]
|
||||
=== Active/Passive
|
||||
|
||||
In an active/passive configuration, systems are set up to bring additional resources online to replace those that have failed. For example, OpenStack would write to the main database while maintaining a disaster recovery database that can be brought online in the event that the main database fails.
|
||||
|
||||
Typically, an active/passive installation for a stateless service would maintain a redundant instance that can be brought online when required. Requests are load balanced using a virtual IP address and a load balancer such as HAProxy.
|
||||
|
||||
A typical active/passive installation for a stateful service maintains a replacement resource that can be brought online when required. A separate application (such as Pacemaker or Corosync) monitors these services, bringing the backup online as necessary.
|
||||
|
||||
// Removed bullets and made into parallel prose. However, I'm not certain on the difference between "a redundant instance" (for stateless) and "a replacement resource" (stateful). Please FIXME.
|
||||
|
||||
[[aa-intro]]
|
||||
=== Active/Active
|
||||
|
||||
In an active/active configuration, systems also use a backup but will manage both the main and redundant systems concurrently. This way, if there is a failure the user is unlikely to notice. The backup system is already online, and takes on increased load while the main system is fixed and brought back online.
|
||||
|
||||
Typically, an active/active installation for a stateless service would maintain a redundant instance, and requests are load balanced using a virtual IP address and a load balancer such as HAProxy.
|
||||
|
||||
A typical active/active installation for a stateful service would include redundant services with all instances having an identical state. For example, updates to one instance of a database would also update all other instances. This way a request to one instance is the same as a request to any other. A load balancer manages the traffic to these systems, ensuring that operational systems always handle the request.
|
||||
|
||||
These are some of the more common ways to implement these high availability architectures, but they are by no means the only ways to do it. The important thing is to make sure that your services are redundant, and available; how you achieve that is up to you. This document will cover some of the more common options for highly available systems.
|
||||
|
||||
|
||||
@ -1,6 +1,6 @@
|
||||
<project xmlns="http://maven.apache.org/POM/4.0.0"
|
||||
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
|
||||
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
|
||||
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
|
||||
<parent>
|
||||
<groupId>org.openstack.docs</groupId>
|
||||
<artifactId>parent-pom</artifactId>
|
||||
@ -13,7 +13,7 @@
|
||||
<name>OpenStack High Availability Guide</name>
|
||||
<properties>
|
||||
<!-- This is set by Jenkins according to the branch. -->
|
||||
<release.path.name>trunk</release.path.name>
|
||||
<release.path.name></release.path.name>
|
||||
<comments.enabled>0</comments.enabled>
|
||||
</properties>
|
||||
<!-- ################################################ -->
|
||||
@ -24,7 +24,7 @@
|
||||
<plugin>
|
||||
<groupId>com.rackspace.cloud.api</groupId>
|
||||
<artifactId>clouddocs-maven-plugin</artifactId>
|
||||
<!-- version is set in ../pom.xml file -->
|
||||
<!-- version set in ../pom.xml -->
|
||||
<executions>
|
||||
<execution>
|
||||
<id>generate-webhelp</id>
|
||||
@ -53,9 +53,9 @@
|
||||
</generateToc>
|
||||
<!-- The following elements sets the autonumbering of sections in output for chapter numbers but no numbered sections-->
|
||||
<sectionAutolabel>0</sectionAutolabel>
|
||||
<tocSectionDepth>1</tocSectionDepth>
|
||||
<sectionLabelIncludesComponentLabel>0</sectionLabelIncludesComponentLabel>
|
||||
<webhelpDirname>high-availability-guide</webhelpDirname>
|
||||
<includeDateInPdfFilename>0</includeDateInPdfFilename>
|
||||
<pdfFilenameBase>high-availability-guide</pdfFilenameBase>
|
||||
</configuration>
|
||||
</execution>
|
||||
|
||||
Loading…
Reference in New Issue
Block a user