Integrating Kafka Publisher into Ceilometer Publisher

https://blueprints.launchpad.net/ceilometer/+spec/kafka-publisher

Apache kafka is messaging broker which enables the ability to publish real-time metering data to applications outside of OpenStack Projects with low-latency and high-throughput.

Problem description

Ceilometer monitors and collects data from OpenStack via notifications sent from existing services or by polling the infrastructure. These real-time collected data have great potential to be used for various kind of analysis. There are many external projects which analyze, serialize, and visualize these metering data, for example, Storm, Elastic Search, Mahout, Jubatus etc. In OpenStack, oslo.messaging library provides nice communication paths, however these communication paths are not so general especially in external to OpenStack projects. Thus, this blueprint is trying to publish ceilometer metering data to such external projects using Kafka, distributed messaging system, and achieve the full potential of ceilometer metering data.

Proposed change

To reduce the cost of implementing a Kafka publisher independently, Ceilometer has to provide the kafka publisher as a publisher plugin. This automates publishing metering data, and developers only have to configure the kafka publisher plugin in pipeline.yaml file like:

publisher:
    - kafka://<broker_ip>?topic=<topic_name>

This way any application that is trying to consume streaming ceilometer metrics via Kafka, can directly consume the ceilometer samples. For example, projects like monasca - https://github.com/stackforge/monasca-thresh can consume the ceilometer metrics that are published by the Ceilometer Kafka publisher.

Alternatives

Inside of the OpenStack, to communicate with each modules is achieved by oslo.messaging, however defacto usage of oslo.messaging is for OpenStack projects and Kafka is supporting for more general usages.

Data model impact

None

REST API impact

None

Security impact

Current security support of Kafka is none. Authentication of clients and ecrypting connections are under implementation. More information can be found in the references.

Pipeline impact

Provide new options to specify kafka publisher as a ceilometer publisher

Other end user impact

None

Performance/Scalability Impacts

The paper related to Kafka says that producers can publish about 50,000 messages/sec on the condition that message size is 200 byte and messages are sent one by one. However, this number is affected by parameters such as message size, the number of replication, batch size (kafka can send multiple messages together), and environments. Roughly, RabbitMQ can publish about 10,000 messages/sec, it means this kafka publihser might not be the bottleneck of performance.

Other deployer impact

None

Developer impact

None

Implementation

Assignee(s)

Primary assignee:
<kshimamu>
Other contributors:
<yudupi>
Ongoing maintainer:
<kshimamu>

Work Items

  • adding a kafka publisher as a ceilometer publisher

Future lifecycle

None

Dependencies

Kafka python package

Testing

None

Documentation Impact

None