ae8470131e
This creates a pool to each memcache server so that connections will not grow without bound. This also adds a proxy config "max_memcache_connections" which can control how many connections are available in the pool. A side effect of the change is that we had to change the memcache calls that used noreply, and instead wait for the result of the request. Leaving with noreply could cause a race condition (specifically in account auto create), due to one request calling `memcache.del(key)` and then `memcache.get(key)` with a different pooled connection. If the delete didn't complete fast enough, the get would return the old value before it was deleted, and thus believe that the account was not autocreated. ClaysMindExploded DocImpact Change-Id: I350720b7bba29e1453894d3d4105ac1ea232595b
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================
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Deployment Guide
|
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================
|
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-----------------------
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Hardware Considerations
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-----------------------
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Swift is designed to run on commodity hardware. At Rackspace, our storage
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servers are currently running fairly generic 4U servers with 24 2T SATA
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drives and 8 cores of processing power. RAID on the storage drives is not
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required and not recommended. Swift's disk usage pattern is the worst
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case possible for RAID, and performance degrades very quickly using RAID 5
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or 6.
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------------------
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Deployment Options
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------------------
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The swift services run completely autonomously, which provides for a lot of
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flexibility when architecting the hardware deployment for swift. The 4 main
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services are:
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#. Proxy Services
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#. Object Services
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#. Container Services
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#. Account Services
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The Proxy Services are more CPU and network I/O intensive. If you are using
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10g networking to the proxy, or are terminating SSL traffic at the proxy,
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greater CPU power will be required.
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The Object, Container, and Account Services (Storage Services) are more disk
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and network I/O intensive.
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The easiest deployment is to install all services on each server. There is
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nothing wrong with doing this, as it scales each service out horizontally.
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At Rackspace, we put the Proxy Services on their own servers and all of the
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Storage Services on the same server. This allows us to send 10g networking to
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the proxy and 1g to the storage servers, and keep load balancing to the
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proxies more manageable. Storage Services scale out horizontally as storage
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servers are added, and we can scale overall API throughput by adding more
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Proxies.
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If you need more throughput to either Account or Container Services, they may
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each be deployed to their own servers. For example you might use faster (but
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more expensive) SAS or even SSD drives to get faster disk I/O to the databases.
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Load balancing and network design is left as an exercise to the reader,
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but this is a very important part of the cluster, so time should be spent
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designing the network for a Swift cluster.
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|
|
|
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---------------------
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Web Front End Options
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---------------------
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Swift comes with an integral web front end. However, it can also be deployed
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as a request processor of an Apache2 using mod_wsgi as described in
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:doc:`Apache Deployment Guide <apache_deployment_guide>`.
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.. _ring-preparing:
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------------------
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Preparing the Ring
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------------------
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The first step is to determine the number of partitions that will be in the
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ring. We recommend that there be a minimum of 100 partitions per drive to
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insure even distribution across the drives. A good starting point might be
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to figure out the maximum number of drives the cluster will contain, and then
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multiply by 100, and then round up to the nearest power of two.
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For example, imagine we are building a cluster that will have no more than
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5,000 drives. That would mean that we would have a total number of 500,000
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partitions, which is pretty close to 2^19, rounded up.
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It is also a good idea to keep the number of partitions small (relatively).
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The more partitions there are, the more work that has to be done by the
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replicators and other backend jobs and the more memory the rings consume in
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process. The goal is to find a good balance between small rings and maximum
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cluster size.
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The next step is to determine the number of replicas to store of the data.
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Currently it is recommended to use 3 (as this is the only value that has
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been tested). The higher the number, the more storage that is used but the
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less likely you are to lose data.
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It is also important to determine how many zones the cluster should have. It is
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recommended to start with a minimum of 5 zones. You can start with fewer, but
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our testing has shown that having at least five zones is optimal when failures
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occur. We also recommend trying to configure the zones at as high a level as
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possible to create as much isolation as possible. Some example things to take
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into consideration can include physical location, power availability, and
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network connectivity. For example, in a small cluster you might decide to
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split the zones up by cabinet, with each cabinet having its own power and
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network connectivity. The zone concept is very abstract, so feel free to use
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it in whatever way best isolates your data from failure. Zones are referenced
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by number, beginning with 1.
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You can now start building the ring with::
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swift-ring-builder <builder_file> create <part_power> <replicas> <min_part_hours>
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This will start the ring build process creating the <builder_file> with
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2^<part_power> partitions. <min_part_hours> is the time in hours before a
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specific partition can be moved in succession (24 is a good value for this).
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Devices can be added to the ring with::
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swift-ring-builder <builder_file> add z<zone>-<ip>:<port>/<device_name>_<meta> <weight>
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This will add a device to the ring where <builder_file> is the name of the
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builder file that was created previously, <zone> is the number of the zone
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this device is in, <ip> is the ip address of the server the device is in,
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<port> is the port number that the server is running on, <device_name> is
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the name of the device on the server (for example: sdb1), <meta> is a string
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of metadata for the device (optional), and <weight> is a float weight that
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determines how many partitions are put on the device relative to the rest of
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the devices in the cluster (a good starting point is 100.0 x TB on the drive).
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Add each device that will be initially in the cluster.
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Once all of the devices are added to the ring, run::
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swift-ring-builder <builder_file> rebalance
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This will distribute the partitions across the drives in the ring. It is
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important whenever making changes to the ring to make all the changes
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|
required before running rebalance. This will ensure that the ring stays as
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|
balanced as possible, and as few partitions are moved as possible.
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The above process should be done to make a ring for each storage service
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(Account, Container and Object). The builder files will be needed in future
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|
changes to the ring, so it is very important that these be kept and backed up.
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The resulting .tar.gz ring file should be pushed to all of the servers in the
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cluster. For more information about building rings, running
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swift-ring-builder with no options will display help text with available
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|
commands and options. More information on how the ring works internally
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can be found in the :doc:`Ring Overview <overview_ring>`.
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.. _general-service-configuration:
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|
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-----------------------------
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General Service Configuration
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-----------------------------
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Most Swift services fall into two categories. Swift's wsgi servers and
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background daemons.
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For more information specific to the configuration of Swift's wsgi servers
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with paste deploy see :ref:`general-server-configuration`
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Configuration for servers and daemons can be expressed together in the same
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file for each type of server, or separately. If a required section for the
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service trying to start is missing there will be an error. The sections not
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|
used by the service are ignored.
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Consider the example of an object storage node. By convention configuration
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for the object-server, object-updater, object-replicator, and object-auditor
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exist in a single file ``/etc/swift/object-server.conf``::
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[DEFAULT]
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[pipeline:main]
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pipeline = object-server
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[app:object-server]
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use = egg:swift#object
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[object-replicator]
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reclaim_age = 259200
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[object-updater]
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[object-auditor]
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Swift services expect a configuration path as the first argument::
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$ swift-object-auditor
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Usage: swift-object-auditor CONFIG [options]
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Error: missing config path argument
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If you omit the object-auditor section this file could not be used as the
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configuration path when starting the ``swift-object-auditor`` daemon::
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$ swift-object-auditor /etc/swift/object-server.conf
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Unable to find object-auditor config section in /etc/swift/object-server.conf
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If the configuration path is a directory instead of a file all of the files in
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the directory with the file extension ".conf" will be combined to generate the
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configuration object which is delivered to the Swift service. This is
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referred to generally as "directory based configuration".
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Directory based configuration leverages ConfigParser's native multi-file
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support. Files ending in ".conf" in the given directory are parsed in
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|
lexicographical order. Filenames starting with '.' are ignored. A mixture of
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file and directory configuration paths is not supported - if the configuration
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path is a file only that file will be parsed.
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The swift service management tool ``swift-init`` has adopted the convention of
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looking for ``/etc/swift/{type}-server.conf.d/`` if the file
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``/etc/swift/{type}-server.conf`` file does not exist.
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When using directory based configuration, if the same option under the same
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section appears more than once in different files, the last value parsed is
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said to override previous occurrences. You can ensure proper override
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|
precedence by prefixing the files in the configuration directory with
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numerical values.::
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/etc/swift/
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default.base
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object-server.conf.d/
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000_default.conf -> ../default.base
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001_default-override.conf
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010_server.conf
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020_replicator.conf
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030_updater.conf
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040_auditor.conf
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You can inspect the resulting combined configuration object using the
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``swift-config`` command line tool
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.. _general-server-configuration:
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----------------------------
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General Server Configuration
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----------------------------
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Swift uses paste.deploy (http://pythonpaste.org/deploy/) to manage server
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configurations.
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Default configuration options are set in the `[DEFAULT]` section, and any
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options specified there can be overridden in any of the other sections BUT
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ONLY BY USING THE SYNTAX ``set option_name = value``. This is the unfortunate
|
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way paste.deploy works and I'll try to explain it in full.
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First, here's an example paste.deploy configuration file::
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[DEFAULT]
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name1 = globalvalue
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name2 = globalvalue
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name3 = globalvalue
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set name4 = globalvalue
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[pipeline:main]
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pipeline = myapp
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[app:myapp]
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use = egg:mypkg#myapp
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name2 = localvalue
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set name3 = localvalue
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set name5 = localvalue
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name6 = localvalue
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The resulting configuration that myapp receives is::
|
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global {'__file__': '/etc/mypkg/wsgi.conf', 'here': '/etc/mypkg',
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'name1': 'globalvalue',
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'name2': 'globalvalue',
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'name3': 'localvalue',
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'name4': 'globalvalue',
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'name5': 'localvalue',
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'set name4': 'globalvalue'}
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local {'name6': 'localvalue'}
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So, `name1` got the global value which is fine since it's only in the `DEFAULT`
|
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section anyway.
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|
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`name2` got the global value from `DEFAULT` even though it appears to be
|
|
overridden in the `app:myapp` subsection. This is just the unfortunate way
|
|
paste.deploy works (at least at the time of this writing.)
|
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`name3` got the local value from the `app:myapp` subsection because it is using
|
|
the special paste.deploy syntax of ``set option_name = value``. So, if you want
|
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a default value for most app/filters but want to overridde it in one
|
|
subsection, this is how you do it.
|
|
|
|
`name4` got the global value from `DEFAULT` since it's only in that section
|
|
anyway. But, since we used the ``set`` syntax in the `DEFAULT` section even
|
|
though we shouldn't, notice we also got a ``set name4`` variable. Weird, but
|
|
probably not harmful.
|
|
|
|
`name5` got the local value from the `app:myapp` subsection since it's only
|
|
there anyway, but notice that it is in the global configuration and not the
|
|
local configuration. This is because we used the ``set`` syntax to set the
|
|
value. Again, weird, but not harmful since Swift just treats the two sets of
|
|
configuration values as one set anyway.
|
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`name6` got the local value from `app:myapp` subsection since it's only there,
|
|
and since we didn't use the ``set`` syntax, it's only in the local
|
|
configuration and not the global one. Though, as indicated above, there is no
|
|
special distinction with Swift.
|
|
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|
That's quite an explanation for something that should be so much simpler, but
|
|
it might be important to know how paste.deploy interprets configuration files.
|
|
The main rule to remember when working with Swift configuration files is:
|
|
|
|
.. note::
|
|
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|
Use the ``set option_name = value`` syntax in subsections if the option is
|
|
also set in the ``[DEFAULT]`` section. Don't get in the habit of always
|
|
using the ``set`` syntax or you'll probably mess up your non-paste.deploy
|
|
configuration files.
|
|
|
|
|
|
|
|
---------------------------
|
|
Object Server Configuration
|
|
---------------------------
|
|
|
|
An Example Object Server configuration can be found at
|
|
etc/object-server.conf-sample in the source code repository.
|
|
|
|
The following configuration options are available:
|
|
|
|
[DEFAULT]
|
|
|
|
=================== ========== =============================================
|
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Option Default Description
|
|
------------------- ---------- ---------------------------------------------
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swift_dir /etc/swift Swift configuration directory
|
|
devices /srv/node Parent directory of where devices are mounted
|
|
mount_check true Whether or not check if the devices are
|
|
mounted to prevent accidentally writing
|
|
to the root device
|
|
bind_ip 0.0.0.0 IP Address for server to bind to
|
|
bind_port 6000 Port for server to bind to
|
|
bind_timeout 30 Seconds to attempt bind before giving up
|
|
workers auto Override the number of pre-forked workers
|
|
that will accept connections. If set it
|
|
should be an integer, zero means no fork. If
|
|
unset, it will try to default to the number
|
|
of effective cpu cores and fallback to one.
|
|
Increasing the number of workers may reduce
|
|
the possibility of slow file system
|
|
operations in one request from negatively
|
|
impacting other requests, but may not be as
|
|
efficient as tuning :ref:`threads_per_disk
|
|
<object-server-options>`
|
|
max_clients 1024 Maximum number of clients one worker can
|
|
process simultaneously (it will actually
|
|
accept(2) N + 1). Setting this to one (1)
|
|
will only handle one request at a time,
|
|
without accepting another request
|
|
concurrently.
|
|
disable_fallocate false Disable "fast fail" fallocate checks if the
|
|
underlying filesystem does not support it.
|
|
log_custom_handlers None Comma-separated list of functions to call
|
|
to setup custom log handlers.
|
|
eventlet_debug false If true, turn on debug logging for eventlet
|
|
fallocate_reserve 0 You can set fallocate_reserve to the number of
|
|
bytes you'd like fallocate to reserve, whether
|
|
there is space for the given file size or not.
|
|
This is useful for systems that behave badly
|
|
when they completely run out of space; you can
|
|
make the services pretend they're out of space
|
|
early.
|
|
=================== ========== =============================================
|
|
|
|
.. _object-server-options:
|
|
|
|
[object-server]
|
|
|
|
================== ============= ===========================================
|
|
Option Default Description
|
|
------------------ ------------- -------------------------------------------
|
|
use paste.deploy entry point for the object
|
|
server. For most cases, this should be
|
|
`egg:swift#object`.
|
|
set log_name object-server Label used when logging
|
|
set log_facility LOG_LOCAL0 Syslog log facility
|
|
set log_level INFO Logging level
|
|
set log_requests True Whether or not to log each request
|
|
user swift User to run as
|
|
node_timeout 3 Request timeout to external services
|
|
conn_timeout 0.5 Connection timeout to external services
|
|
network_chunk_size 65536 Size of chunks to read/write over the
|
|
network
|
|
disk_chunk_size 65536 Size of chunks to read/write to disk
|
|
max_upload_time 86400 Maximum time allowed to upload an object
|
|
slow 0 If > 0, Minimum time in seconds for a PUT
|
|
or DELETE request to complete
|
|
mb_per_sync 512 On PUT requests, sync file every n MB
|
|
keep_cache_size 5242880 Largest object size to keep in buffer cache
|
|
keep_cache_private false Allow non-public objects to stay in
|
|
kernel's buffer cache
|
|
threads_per_disk 0 Size of the per-disk thread pool used for
|
|
performing disk I/O. The default of 0 means
|
|
to not use a per-disk thread pool. It is
|
|
recommended to keep this value small, as
|
|
large values can result in high read
|
|
latencies due to large queue depths. A good
|
|
starting point is 4 threads per disk.
|
|
================== ============= ===========================================
|
|
|
|
[object-replicator]
|
|
|
|
================== ================= =======================================
|
|
Option Default Description
|
|
------------------ ----------------- ---------------------------------------
|
|
log_name object-replicator Label used when logging
|
|
log_facility LOG_LOCAL0 Syslog log facility
|
|
log_level INFO Logging level
|
|
daemonize yes Whether or not to run replication as a
|
|
daemon
|
|
run_pause 30 Time in seconds to wait between
|
|
replication passes
|
|
concurrency 1 Number of replication workers to spawn
|
|
timeout 5 Timeout value sent to rsync --timeout
|
|
and --contimeout options
|
|
stats_interval 3600 Interval in seconds between logging
|
|
replication statistics
|
|
reclaim_age 604800 Time elapsed in seconds before an
|
|
object can be reclaimed
|
|
handoffs_first false If set to True, partitions that are
|
|
not supposed to be on the node will be
|
|
replicated first. The default setting
|
|
should not be changed, except for
|
|
extreme situations.
|
|
handoff_delete auto By default handoff partitions will be
|
|
removed when it has successfully
|
|
replicated to all the cannonical nodes.
|
|
If set to an integer n, it will remove
|
|
the partition if it is successfully
|
|
replicated to n nodes. The default
|
|
setting should not be changed, except
|
|
for extremem situations.
|
|
================== ================= =======================================
|
|
|
|
[object-updater]
|
|
|
|
================== ============== ==========================================
|
|
Option Default Description
|
|
------------------ -------------- ------------------------------------------
|
|
log_name object-updater Label used when logging
|
|
log_facility LOG_LOCAL0 Syslog log facility
|
|
log_level INFO Logging level
|
|
interval 300 Minimum time for a pass to take
|
|
concurrency 1 Number of updater workers to spawn
|
|
node_timeout 10 Request timeout to external services
|
|
conn_timeout 0.5 Connection timeout to external services
|
|
slowdown 0.01 Time in seconds to wait between objects
|
|
================== ============== ==========================================
|
|
|
|
[object-auditor]
|
|
|
|
================== ============== ==========================================
|
|
Option Default Description
|
|
------------------ -------------- ------------------------------------------
|
|
log_name object-auditor Label used when logging
|
|
log_facility LOG_LOCAL0 Syslog log facility
|
|
log_level INFO Logging level
|
|
log_time 3600 Frequency of status logs in seconds.
|
|
files_per_second 20 Maximum files audited per second. Should
|
|
be tuned according to individual system
|
|
specs. 0 is unlimited.
|
|
bytes_per_second 10000000 Maximum bytes audited per second. Should
|
|
be tuned according to individual system
|
|
specs. 0 is unlimited.
|
|
================== ============== ==========================================
|
|
|
|
------------------------------
|
|
Container Server Configuration
|
|
------------------------------
|
|
|
|
An example Container Server configuration can be found at
|
|
etc/container-server.conf-sample in the source code repository.
|
|
|
|
The following configuration options are available:
|
|
|
|
[DEFAULT]
|
|
|
|
=================== ========== ============================================
|
|
Option Default Description
|
|
------------------- ---------- --------------------------------------------
|
|
swift_dir /etc/swift Swift configuration directory
|
|
devices /srv/node Parent directory of where devices are mounted
|
|
mount_check true Whether or not check if the devices are
|
|
mounted to prevent accidentally writing
|
|
to the root device
|
|
bind_ip 0.0.0.0 IP Address for server to bind to
|
|
bind_port 6001 Port for server to bind to
|
|
bind_timeout 30 Seconds to attempt bind before giving up
|
|
workers auto Override the number of pre-forked workers
|
|
that will accept connections. If set it
|
|
should be an integer, zero means no fork. If
|
|
unset, it will try to default to the number
|
|
of effective cpu cores and fallback to one.
|
|
Increasing the number of workers may reduce
|
|
the possibility of slow file system
|
|
operations in one request from negatively
|
|
impacting other requests. See
|
|
:ref:`general-service-tuning`
|
|
max_clients 1024 Maximum number of clients one worker can
|
|
process simultaneously (it will actually
|
|
accept(2) N + 1). Setting this to one (1)
|
|
will only handle one request at a time,
|
|
without accepting another request
|
|
concurrently.
|
|
user swift User to run as
|
|
disable_fallocate false Disable "fast fail" fallocate checks if the
|
|
underlying filesystem does not support it.
|
|
log_custom_handlers None Comma-separated list of functions to call
|
|
to setup custom log handlers.
|
|
eventlet_debug false If true, turn on debug logging for eventlet
|
|
fallocate_reserve 0 You can set fallocate_reserve to the number of
|
|
bytes you'd like fallocate to reserve, whether
|
|
there is space for the given file size or not.
|
|
This is useful for systems that behave badly
|
|
when they completely run out of space; you can
|
|
make the services pretend they're out of space
|
|
early.
|
|
=================== ========== ============================================
|
|
|
|
[container-server]
|
|
|
|
================== ================ ========================================
|
|
Option Default Description
|
|
------------------ ---------------- ----------------------------------------
|
|
use paste.deploy entry point for the
|
|
container server. For most cases, this
|
|
should be `egg:swift#container`.
|
|
set log_name container-server Label used when logging
|
|
set log_facility LOG_LOCAL0 Syslog log facility
|
|
set log_level INFO Logging level
|
|
node_timeout 3 Request timeout to external services
|
|
conn_timeout 0.5 Connection timeout to external services
|
|
allow_versions false Enable/Disable object versioning feature
|
|
================== ================ ========================================
|
|
|
|
[container-replicator]
|
|
|
|
================== ==================== ====================================
|
|
Option Default Description
|
|
------------------ -------------------- ------------------------------------
|
|
log_name container-replicator Label used when logging
|
|
log_facility LOG_LOCAL0 Syslog log facility
|
|
log_level INFO Logging level
|
|
per_diff 1000
|
|
concurrency 8 Number of replication workers to
|
|
spawn
|
|
run_pause 30 Time in seconds to wait between
|
|
replication passes
|
|
node_timeout 10 Request timeout to external services
|
|
conn_timeout 0.5 Connection timeout to external
|
|
services
|
|
reclaim_age 604800 Time elapsed in seconds before a
|
|
container can be reclaimed
|
|
================== ==================== ====================================
|
|
|
|
[container-updater]
|
|
|
|
======================== ================= ==================================
|
|
Option Default Description
|
|
------------------------ ----------------- ----------------------------------
|
|
log_name container-updater Label used when logging
|
|
log_facility LOG_LOCAL0 Syslog log facility
|
|
log_level INFO Logging level
|
|
interval 300 Minimum time for a pass to take
|
|
concurrency 4 Number of updater workers to spawn
|
|
node_timeout 3 Request timeout to external
|
|
services
|
|
conn_timeout 0.5 Connection timeout to external
|
|
services
|
|
slowdown 0.01 Time in seconds to wait between
|
|
containers
|
|
account_suppression_time 60 Seconds to suppress updating an
|
|
account that has generated an
|
|
error (timeout, not yet found,
|
|
etc.)
|
|
======================== ================= ==================================
|
|
|
|
[container-auditor]
|
|
|
|
===================== ================= =======================================
|
|
Option Default Description
|
|
--------------------- ----------------- ---------------------------------------
|
|
log_name container-auditor Label used when logging
|
|
log_facility LOG_LOCAL0 Syslog log facility
|
|
log_level INFO Logging level
|
|
interval 1800 Minimum time for a pass to take
|
|
containers_per_second 200 Maximum containers audited per second.
|
|
Should be tuned according to individual
|
|
system specs. 0 is unlimited.
|
|
===================== ================= =======================================
|
|
|
|
----------------------------
|
|
Account Server Configuration
|
|
----------------------------
|
|
|
|
An example Account Server configuration can be found at
|
|
etc/account-server.conf-sample in the source code repository.
|
|
|
|
The following configuration options are available:
|
|
|
|
[DEFAULT]
|
|
|
|
=================== ========== =============================================
|
|
Option Default Description
|
|
------------------- ---------- ---------------------------------------------
|
|
swift_dir /etc/swift Swift configuration directory
|
|
devices /srv/node Parent directory or where devices are mounted
|
|
mount_check true Whether or not check if the devices are
|
|
mounted to prevent accidentally writing
|
|
to the root device
|
|
bind_ip 0.0.0.0 IP Address for server to bind to
|
|
bind_port 6002 Port for server to bind to
|
|
bind_timeout 30 Seconds to attempt bind before giving up
|
|
workers auto Override the number of pre-forked workers
|
|
that will accept connections. If set it
|
|
should be an integer, zero means no fork. If
|
|
unset, it will try to default to the number
|
|
of effective cpu cores and fallback to one.
|
|
Increasing the number of workers may reduce
|
|
the possibility of slow file system
|
|
operations in one request from negatively
|
|
impacting other requests. See
|
|
:ref:`general-service-tuning`
|
|
max_clients 1024 Maximum number of clients one worker can
|
|
process simultaneously (it will actually
|
|
accept(2) N + 1). Setting this to one (1)
|
|
will only handle one request at a time,
|
|
without accepting another request
|
|
concurrently.
|
|
user swift User to run as
|
|
db_preallocation off If you don't mind the extra disk space usage in
|
|
overhead, you can turn this on to preallocate
|
|
disk space with SQLite databases to decrease
|
|
fragmentation.
|
|
disable_fallocate false Disable "fast fail" fallocate checks if the
|
|
underlying filesystem does not support it.
|
|
log_custom_handlers None Comma-separated list of functions to call
|
|
to setup custom log handlers.
|
|
eventlet_debug false If true, turn on debug logging for eventlet
|
|
fallocate_reserve 0 You can set fallocate_reserve to the number of
|
|
bytes you'd like fallocate to reserve, whether
|
|
there is space for the given file size or not.
|
|
This is useful for systems that behave badly
|
|
when they completely run out of space; you can
|
|
make the services pretend they're out of space
|
|
early.
|
|
=================== ========== =============================================
|
|
|
|
[account-server]
|
|
|
|
================== ============== ==========================================
|
|
Option Default Description
|
|
------------------ -------------- ------------------------------------------
|
|
use Entry point for paste.deploy for the account
|
|
server. For most cases, this should be
|
|
`egg:swift#account`.
|
|
set log_name account-server Label used when logging
|
|
set log_facility LOG_LOCAL0 Syslog log facility
|
|
set log_level INFO Logging level
|
|
================== ============== ==========================================
|
|
|
|
[account-replicator]
|
|
|
|
================== ================== ======================================
|
|
Option Default Description
|
|
------------------ ------------------ --------------------------------------
|
|
log_name account-replicator Label used when logging
|
|
log_facility LOG_LOCAL0 Syslog log facility
|
|
log_level INFO Logging level
|
|
per_diff 1000
|
|
concurrency 8 Number of replication workers to spawn
|
|
run_pause 30 Time in seconds to wait between
|
|
replication passes
|
|
node_timeout 10 Request timeout to external services
|
|
conn_timeout 0.5 Connection timeout to external services
|
|
reclaim_age 604800 Time elapsed in seconds before an
|
|
account can be reclaimed
|
|
================== ================== ======================================
|
|
|
|
[account-auditor]
|
|
|
|
==================== =============== =======================================
|
|
Option Default Description
|
|
-------------------- --------------- ---------------------------------------
|
|
log_name account-auditor Label used when logging
|
|
log_facility LOG_LOCAL0 Syslog log facility
|
|
log_level INFO Logging level
|
|
interval 1800 Minimum time for a pass to take
|
|
accounts_per_second 200 Maximum accounts audited per second.
|
|
Should be tuned according to individual
|
|
system specs. 0 is unlimited.
|
|
==================== =============== =======================================
|
|
|
|
[account-reaper]
|
|
|
|
================== =============== =========================================
|
|
Option Default Description
|
|
------------------ --------------- -----------------------------------------
|
|
log_name account-auditor Label used when logging
|
|
log_facility LOG_LOCAL0 Syslog log facility
|
|
log_level INFO Logging level
|
|
concurrency 25 Number of replication workers to spawn
|
|
interval 3600 Minimum time for a pass to take
|
|
node_timeout 10 Request timeout to external services
|
|
conn_timeout 0.5 Connection timeout to external services
|
|
delay_reaping 0 Normally, the reaper begins deleting
|
|
account information for deleted accounts
|
|
immediately; you can set this to delay
|
|
its work however. The value is in seconds,
|
|
2592000 = 30 days, for example.
|
|
================== =============== =========================================
|
|
|
|
--------------------------
|
|
Proxy Server Configuration
|
|
--------------------------
|
|
|
|
An example Proxy Server configuration can be found at
|
|
etc/proxy-server.conf-sample in the source code repository.
|
|
|
|
The following configuration options are available:
|
|
|
|
[DEFAULT]
|
|
|
|
============================ =============== =============================
|
|
Option Default Description
|
|
---------------------------- --------------- -----------------------------
|
|
bind_ip 0.0.0.0 IP Address for server to
|
|
bind to
|
|
bind_port 80 Port for server to bind to
|
|
bind_timeout 30 Seconds to attempt bind before
|
|
giving up
|
|
swift_dir /etc/swift Swift configuration directory
|
|
workers auto Override the number of
|
|
pre-forked workers that will
|
|
accept connections. If set it
|
|
should be an integer, zero
|
|
means no fork. If unset, it
|
|
will try to default to the
|
|
number of effective cpu cores
|
|
and fallback to one. See
|
|
:ref:`general-service-tuning`
|
|
max_clients 1024 Maximum number of clients one
|
|
worker can process
|
|
simultaneously (it will
|
|
actually accept(2) N +
|
|
1). Setting this to one (1)
|
|
will only handle one request at
|
|
a time, without accepting
|
|
another request
|
|
concurrently.
|
|
user swift User to run as
|
|
cert_file Path to the ssl .crt. This
|
|
should be enabled for testing
|
|
purposes only.
|
|
key_file Path to the ssl .key. This
|
|
should be enabled for testing
|
|
purposes only.
|
|
cors_allow_origin This is a list of hosts that
|
|
are included with any CORS
|
|
request by default and
|
|
returned with the
|
|
Access-Control-Allow-Origin
|
|
header in addition to what
|
|
the container has set.
|
|
log_custom_handlers None Comma separated list of functions
|
|
to call to setup custom log
|
|
handlers.
|
|
eventlet_debug false If true, turn on debug logging
|
|
for eventlet
|
|
============================ =============== =============================
|
|
|
|
[proxy-server]
|
|
|
|
============================ =============== =============================
|
|
Option Default Description
|
|
---------------------------- --------------- -----------------------------
|
|
use Entry point for paste.deploy for
|
|
the proxy server. For most
|
|
cases, this should be
|
|
`egg:swift#proxy`.
|
|
set log_name proxy-server Label used when logging
|
|
set log_facility LOG_LOCAL0 Syslog log facility
|
|
set log_level INFO Log level
|
|
set log_headers True If True, log headers in each
|
|
request
|
|
set log_handoffs True If True, the proxy will log
|
|
whenever it has to failover to a
|
|
handoff node
|
|
recheck_account_existence 60 Cache timeout in seconds to
|
|
send memcached for account
|
|
existence
|
|
recheck_container_existence 60 Cache timeout in seconds to
|
|
send memcached for container
|
|
existence
|
|
object_chunk_size 65536 Chunk size to read from
|
|
object servers
|
|
client_chunk_size 65536 Chunk size to read from
|
|
clients
|
|
memcache_servers 127.0.0.1:11211 Comma separated list of
|
|
memcached servers ip:port
|
|
memcache_max_connections 2 Max number of connections to
|
|
each memcached server per
|
|
worker
|
|
node_timeout 10 Request timeout to external
|
|
services
|
|
client_timeout 60 Timeout to read one chunk
|
|
from a client
|
|
conn_timeout 0.5 Connection timeout to
|
|
external services
|
|
error_suppression_interval 60 Time in seconds that must
|
|
elapse since the last error
|
|
for a node to be considered
|
|
no longer error limited
|
|
error_suppression_limit 10 Error count to consider a
|
|
node error limited
|
|
allow_account_management false Whether account PUTs and DELETEs
|
|
are even callable
|
|
object_post_as_copy true Set object_post_as_copy = false
|
|
to turn on fast posts where only
|
|
the metadata changes are stored
|
|
anew and the original data file
|
|
is kept in place. This makes for
|
|
quicker posts; but since the
|
|
container metadata isn't updated
|
|
in this mode, features like
|
|
container sync won't be able to
|
|
sync posts.
|
|
account_autocreate false If set to 'true' authorized
|
|
accounts that do not yet exist
|
|
within the Swift cluster will
|
|
be automatically created.
|
|
max_containers_per_account 0 If set to a positive value,
|
|
trying to create a container
|
|
when the account already has at
|
|
least this maximum containers
|
|
will result in a 403 Forbidden.
|
|
Note: This is a soft limit,
|
|
meaning a user might exceed the
|
|
cap for
|
|
recheck_account_existence before
|
|
the 403s kick in.
|
|
max_containers_whitelist This is a comma separated list
|
|
of account names that ignore
|
|
the max_containers_per_account
|
|
cap.
|
|
rate_limit_after_segment 10 Rate limit the download of
|
|
large object segments after
|
|
this segment is downloaded.
|
|
rate_limit_segments_per_sec 1 Rate limit large object
|
|
downloads at this rate.
|
|
request_node_count 2 * replicas Set to the number of nodes to
|
|
contact for a normal request.
|
|
You can use '* replicas' at the
|
|
end to have it use the number
|
|
given times the number of
|
|
replicas for the ring being used
|
|
for the request.
|
|
swift_owner_headers <see the sample These are the headers whose
|
|
conf file for values will only be shown to
|
|
the list of swift_owners. The exact
|
|
default definition of a swift_owner is
|
|
headers> up to the auth system in use,
|
|
but usually indicates
|
|
administrative responsibilities.
|
|
============================ =============== =============================
|
|
|
|
[tempauth]
|
|
|
|
===================== =============================== =======================
|
|
Option Default Description
|
|
--------------------- ------------------------------- -----------------------
|
|
use Entry point for
|
|
paste.deploy to use for
|
|
auth. To use tempauth
|
|
set to:
|
|
`egg:swift#tempauth`
|
|
set log_name tempauth Label used when logging
|
|
set log_facility LOG_LOCAL0 Syslog log facility
|
|
set log_level INFO Log level
|
|
set log_headers True If True, log headers in
|
|
each request
|
|
reseller_prefix AUTH The naming scope for the
|
|
auth service. Swift
|
|
storage accounts and
|
|
auth tokens will begin
|
|
with this prefix.
|
|
auth_prefix /auth/ The HTTP request path
|
|
prefix for the auth
|
|
service. Swift itself
|
|
reserves anything
|
|
beginning with the
|
|
letter `v`.
|
|
token_life 86400 The number of seconds a
|
|
token is valid.
|
|
storage_url_scheme default Scheme to return with
|
|
storage urls: http,
|
|
https, or default
|
|
(chooses based on what
|
|
the server is running
|
|
as) This can be useful
|
|
with an SSL load
|
|
balancer in front of a
|
|
non-SSL server.
|
|
===================== =============================== =======================
|
|
|
|
Additionally, you need to list all the accounts/users you want here. The format
|
|
is::
|
|
|
|
user_<account>_<user> = <key> [group] [group] [...] [storage_url]
|
|
|
|
or if you want to be able to include underscores in the ``<account>`` or
|
|
``<user>`` portions, you can base64 encode them (with *no* equal signs) in a
|
|
line like this::
|
|
|
|
user64_<account_b64>_<user_b64> = <key> [group] [group] [...] [storage_url]
|
|
|
|
There are special groups of::
|
|
|
|
.reseller_admin = can do anything to any account for this auth
|
|
.admin = can do anything within the account
|
|
|
|
If neither of these groups are specified, the user can only access containers
|
|
that have been explicitly allowed for them by a .admin or .reseller_admin.
|
|
|
|
The trailing optional storage_url allows you to specify an alternate url to
|
|
hand back to the user upon authentication. If not specified, this defaults to::
|
|
|
|
$HOST/v1/<reseller_prefix>_<account>
|
|
|
|
Where $HOST will do its best to resolve to what the requester would need to use
|
|
to reach this host, <reseller_prefix> is from this section, and <account> is
|
|
from the user_<account>_<user> name. Note that $HOST cannot possibly handle
|
|
when you have a load balancer in front of it that does https while TempAuth
|
|
itself runs with http; in such a case, you'll have to specify the
|
|
storage_url_scheme configuration value as an override.
|
|
|
|
Here are example entries, required for running the tests::
|
|
|
|
user_admin_admin = admin .admin .reseller_admin
|
|
user_test_tester = testing .admin
|
|
user_test2_tester2 = testing2 .admin
|
|
user_test_tester3 = testing3
|
|
|
|
# account "test_y" and user "tester_y" (note the lack of padding = chars)
|
|
user64_dGVzdF95_dGVzdGVyX3k = testing4 .admin
|
|
|
|
------------------------
|
|
Memcached Considerations
|
|
------------------------
|
|
|
|
Several of the Services rely on Memcached for caching certain types of
|
|
lookups, such as auth tokens, and container/account existence. Swift does
|
|
not do any caching of actual object data. Memcached should be able to run
|
|
on any servers that have available RAM and CPU. At Rackspace, we run
|
|
Memcached on the proxy servers. The `memcache_servers` config option
|
|
in the `proxy-server.conf` should contain all memcached servers.
|
|
|
|
-----------
|
|
System Time
|
|
-----------
|
|
|
|
Time may be relative but it is relatively important for Swift! Swift uses
|
|
timestamps to determine which is the most recent version of an object.
|
|
It is very important for the system time on each server in the cluster to
|
|
by synced as closely as possible (more so for the proxy server, but in general
|
|
it is a good idea for all the servers). At Rackspace, we use NTP with a local
|
|
NTP server to ensure that the system times are as close as possible. This
|
|
should also be monitored to ensure that the times do not vary too much.
|
|
|
|
.. _general-service-tuning:
|
|
|
|
----------------------
|
|
General Service Tuning
|
|
----------------------
|
|
|
|
Most services support either a `worker` or `concurrency` value in the
|
|
settings. This allows the services to make effective use of the cores
|
|
available. A good starting point to set the concurrency level for the proxy
|
|
and storage services to 2 times the number of cores available. If more than
|
|
one service is sharing a server, then some experimentation may be needed to
|
|
find the best balance.
|
|
|
|
At Rackspace, our Proxy servers have dual quad core processors, giving us 8
|
|
cores. Our testing has shown 16 workers to be a pretty good balance when
|
|
saturating a 10g network and gives good CPU utilization.
|
|
|
|
Our Storage servers all run together on the same servers. These servers have
|
|
dual quad core processors, for 8 cores total. We run the Account, Container,
|
|
and Object servers with 8 workers each. Most of the background jobs are run at
|
|
a concurrency of 1, with the exception of the replicators which are run at a
|
|
concurrency of 2.
|
|
|
|
The `max_clients` parameter can be used to adjust the number of client
|
|
requests an individual worker accepts for processing. The fewer requests being
|
|
processed at one time, the less likely a request that consumes the worker's
|
|
CPU time, or blocks in the OS, will negatively impact other requests. The more
|
|
requests being processed at one time, the more likely one worker can utilize
|
|
network and disk capacity.
|
|
|
|
On systems that have more cores, and more memory, where one can afford to run
|
|
more workers, raising the number of workers and lowering the maximum number of
|
|
clients serviced per worker can lessen the impact of CPU intensive or stalled
|
|
requests.
|
|
|
|
The above configuration setting should be taken as suggestions and testing
|
|
of configuration settings should be done to ensure best utilization of CPU,
|
|
network connectivity, and disk I/O.
|
|
|
|
-------------------------
|
|
Filesystem Considerations
|
|
-------------------------
|
|
|
|
Swift is designed to be mostly filesystem agnostic--the only requirement
|
|
being that the filesystem supports extended attributes (xattrs). After
|
|
thorough testing with our use cases and hardware configurations, XFS was
|
|
the best all-around choice. If you decide to use a filesystem other than
|
|
XFS, we highly recommend thorough testing.
|
|
|
|
For distros with more recent kernels (for example Ubuntu 12.04 Precise),
|
|
we recommend using the default settings (including the default inode size
|
|
of 256 bytes) when creating the file system::
|
|
|
|
mkfs.xfs /dev/sda1
|
|
|
|
In the last couple of years, XFS has made great improvements in how inodes
|
|
are allocated and used. Using the default inode size no longer has an
|
|
impact on performance.
|
|
|
|
For distros with older kernels (for example Ubuntu 10.04 Lucid),
|
|
some settings can dramatically impact performance. We recommend the
|
|
following when creating the file system::
|
|
|
|
mkfs.xfs -i size=1024 /dev/sda1
|
|
|
|
Setting the inode size is important, as XFS stores xattr data in the inode.
|
|
If the metadata is too large to fit in the inode, a new extent is created,
|
|
which can cause quite a performance problem. Upping the inode size to 1024
|
|
bytes provides enough room to write the default metadata, plus a little
|
|
headroom.
|
|
|
|
The following example mount options are recommended when using XFS::
|
|
|
|
mount -t xfs -o noatime,nodiratime,nobarrier,logbufs=8 /dev/sda1 /srv/node/sda
|
|
|
|
We do not recommend running Swift on RAID, but if you are using
|
|
RAID it is also important to make sure that the proper sunit and swidth
|
|
settings get set so that XFS can make most efficient use of the RAID array.
|
|
|
|
For a standard swift install, all data drives are mounted directly under
|
|
/srv/node (as can be seen in the above example of mounting /def/sda1 as
|
|
/srv/node/sda). If you choose to mount the drives in another directory,
|
|
be sure to set the `devices` config option in all of the server configs to
|
|
point to the correct directory.
|
|
|
|
Swift uses system calls to reserve space for new objects being written into
|
|
the system. If your filesystem does not support `fallocate()` or
|
|
`posix_fallocate()`, be sure to set the `disable_fallocate = true` config
|
|
parameter in account, container, and object server configs.
|
|
|
|
---------------------
|
|
General System Tuning
|
|
---------------------
|
|
|
|
Rackspace currently runs Swift on Ubuntu Server 10.04, and the following
|
|
changes have been found to be useful for our use cases.
|
|
|
|
The following settings should be in `/etc/sysctl.conf`::
|
|
|
|
# disable TIME_WAIT.. wait..
|
|
net.ipv4.tcp_tw_recycle=1
|
|
net.ipv4.tcp_tw_reuse=1
|
|
|
|
# disable syn cookies
|
|
net.ipv4.tcp_syncookies = 0
|
|
|
|
# double amount of allowed conntrack
|
|
net.ipv4.netfilter.ip_conntrack_max = 262144
|
|
|
|
To load the updated sysctl settings, run ``sudo sysctl -p``
|
|
|
|
A note about changing the TIME_WAIT values. By default the OS will hold
|
|
a port open for 60 seconds to ensure that any remaining packets can be
|
|
received. During high usage, and with the number of connections that are
|
|
created, it is easy to run out of ports. We can change this since we are
|
|
in control of the network. If you are not in control of the network, or
|
|
do not expect high loads, then you may not want to adjust those values.
|
|
|
|
----------------------
|
|
Logging Considerations
|
|
----------------------
|
|
|
|
Swift is set up to log directly to syslog. Every service can be configured
|
|
with the `log_facility` option to set the syslog log facility destination.
|
|
We recommended using syslog-ng to route the logs to specific log
|
|
files locally on the server and also to remote log collecting servers.
|
|
Additionally, custom log handlers can be used via the custom_log_handlers
|
|
setting.
|