In this patch 1.) Fix rst mark-ups 2.) In one file there is a link for config-ref of kilo version so it is updated with liberty version Change-Id: I832b61b0c605002653a8e8abb5c206c7c6197e8f
5.3 KiB
System architecture
The Telemetry service uses an agent-based architecture. Several modules combine their responsibilities to collect data, store samples in a database, or provide an API service for handling incoming requests.
The Telemetry service is built from the following agents and services:
- ceilometer-api
-
Presents aggregated metering data to consumers (such as billing engines and analytics tools).
- ceilometer-polling
-
Polls for different kinds of meter data by using the polling plug-ins (pollsters) registered in different namespaces. It provides a single polling interface across different namespaces.
- ceilometer-agent-central
-
Polls the public RESTful APIs of other OpenStack services such as Compute service and Image service, in order to keep tabs on resource existence, by using the polling plug-ins (pollsters) registered in the central polling namespace.
- ceilometer-agent-compute
-
Polls the local hypervisor or libvirt daemon to acquire performance data for the local instances, messages and emits the data as AMQP messages, by using the polling plug-ins (pollsters) registered in the compute polling namespace.
- ceilometer-agent-ipmi
-
Polls the local node with IPMI support, in order to acquire IPMI sensor data and Intel Node Manager data, by using the polling plug-ins (pollsters) registered in the IPMI polling namespace.
- ceilometer-agent-notification
-
Consumes AMQP messages from other OpenStack services.
- ceilometer-collector
-
Consumes AMQP notifications from the agents, then dispatches these data to the appropriate data store.
- ceilometer-alarm-evaluator
-
Determines when alarms fire due to the associated statistic trend crossing a threshold over a sliding time window.
- ceilometer-alarm-notifier
-
Initiates alarm actions, for example calling out to a webhook with a description of the alarm state transition.
Note
The
ceilometer-polling
service is available since the Kilo release. It is intended to replaceceilometer-agent-central
,ceilometer-agent-compute
, andceilometer-agent-ipmi
.
Besides the ceilometer-agent-compute
and the
ceilometer-agent-ipmi
services, all the other services are
placed on one or more controller nodes.
The Telemetry architecture highly depends on the AMQP service both for consuming notifications coming from OpenStack services and internal communication.
Supported databases
The other key external component of Telemetry is the database, where events, samples, alarm definitions, and alarms are stored.
Note
Multiple database back ends can be configured in order to store events, samples, and alarms separately.
The list of supported database back ends:
Supported hypervisors
The Telemetry service collects information about the virtual machines, which requires close connection to the hypervisor that runs on the compute hosts.
The following is a list of supported hypervisors.
The following hypervisors are supported via libvirt
- Kernel-based Virtual Machine (KVM)
- Quick Emulator (QEMU)
- Linux Containers (LXC)
- User-mode Linux (UML)
Note
For details about hypervisor support in libvirt please check the Libvirt API support matrix.
Supported networking services
Telemetry is able to retrieve information from OpenStack Networking and external networking services:
- OpenStack Networking:
- Basic network meters
- Firewall-as-a-Service (FWaaS) meters
- Load-Balancer-as-a-Service (LBaaS) meters
- VPN-as-a-Service (VPNaaS) meters
- SDN controller meters:
Users, roles, and tenants
This service of OpenStack uses OpenStack Identity for authenticating and authorizing users. The required configuration options are listed in the Telemetry section in the OpenStack Configuration Reference.
The system uses two roles:admin
and
non-admin
. The authorization happens before processing each
API request. The amount of returned data depends on the role the
requestor owns.
The creation of alarm definitions also highly depends on the role of
the user, who initiated the action. Further details about telemetry-alarms
handling can
be found in this guide.