The OpenStack ceilometer-agent-central is a component of the OpenStack Telemetry (Ceilometer) project. Ceilometer is designed to collect, process, and store metering data in an OpenStack environment. The ceilometer-agent-central specifically plays a role in collecting metering data from various OpenStack services.
This is actually the polling agent ceilometer-polling running with parameter --polling-namespace central.
Here are some details about the ceilometer-agent-central component:
- Purpose: The ceilometer-agent-central is responsible for collecting metering data from different OpenStack services, including compute (Nova), block storage (Cinder), image (Glance), networking (Neutron), and other services. It acts as a central agent for collecting and processing metering data.
- Metering Data Collection: The agent-central retrieves metering data from various OpenStack services through their respective APIs. It collects information about resource utilization, such as CPU usage, memory usage, network traffic, and other relevant metrics.
- Data Processing: Once the metering data is collected, the ceilometer-agent-central processes and transforms it into a format suitable for storage and analysis. This may involve data normalization, aggregation, and filtering based on configuration settings.
- Message Queue: The ceilometer-agent-central component utilizes a message queue, typically RabbitMQ, to exchange messages with other ceilometer components. It publishes collected metering data to the message queue for further processing.
- Publisher: As part of its role, the agent-central acts as a publisher by sending metering data to the ceilometer message queue. This allows other ceilometer components, such as the collector and notifier, to consume and process the data.
- Configuration: The ceilometer-agent-central is configured through the ceilometer configuration file (
ceilometer.conf). The configuration specifies which OpenStack services to monitor, the polling intervals, the metering data collection settings, and the message queue connection details. - Scalability: The ceilometer-agent-central can be deployed on multiple compute nodes or other relevant OpenStack services to ensure scalability and distribute the load of metering data collection. This allows for efficient monitoring of a large-scale OpenStack deployment.
- Integration with other Ceilometer Components: The agent-central component works in conjunction with other ceilometer components, such as the ceilometer-collector and ceilometer-notifier. The collector component receives metering data from the message queue and stores it in the ceilometer database, while the notifier component generates notifications based on predefined rules.
- Database Storage: The collected metering data is typically stored in a backend database, such as MongoDB or an SQL database. The ceilometer-agent-central does not directly interact with the database but relies on the collector component to handle storage.
Overall, the ceilometer-agent-central is a vital component of the Ceilometer project in OpenStack. It serves as a bridge between the various OpenStack services and the Ceilometer system, enabling the collection and processing of metering data for monitoring and resource utilization analysis.