69 lines
2.2 KiB
ReStructuredText
69 lines
2.2 KiB
ReStructuredText
monasca-persister
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=================
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.. warning::
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Java implementation of monasca-persister is deprecated as of Train release.
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The Monasca Persister consumes metrics and alarm state transitions
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from the Apache Kafka message queue and stores them in the time series
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database.
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Although the Persister isn't primarily a Web service it uses DropWizard,
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https://dropwizard.github.io/dropwizard/, which provides a nice Web
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application framework to expose an http endpoint that provides an
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interface through which metrics about the Persister can be queried as
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well as health status.
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The basic design of the Persister is to have one Kafka consumer publish
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to a Disruptor, https://github.com/LMAX-Exchange/disruptor, that has
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output processors. The output processors use prepared batch statements
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to write to the Metrics and Alarms database.
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The number of output processors/threads in the Persister can be
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specified to scale to more messages. To horizontally scale and provide
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fault-tolerance any number of Persisters can be started as consumers
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from the Message Queue.
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Build
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=====
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Requires monasca-common from
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https://opendev.org/openstack/monasca-common. Download and build
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following instructions in its README.rst. Then build monasca-persister
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by:
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::
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mvn clean package
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Configuration
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=============
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A sample configuration file is available in
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java/src/deb/etc/persister-config.yml-sample.
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A second configuration file is provided in
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java/src/main/resources/persister-config.yml for use with the `vagrant
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"mini-mon" development environment`_.
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TODO
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====
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The following list is historic. Current work is tracked in `Storyboard`_.
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- Purge metrics on shutdown
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- Add more robust offset management in Kafka. Currently, the offset is
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advanced as each message is read. If the Persister stops after the
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metric has been read and prior to it being committed to the Metrics
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and Alarms database, the metric will be lost.
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- Add better handling of SQL exceptions.
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- Complete health check.
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- Specify and document the names of the metrics that are available for
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monitoring of the Persister.
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- Document the yaml configuration parameters.
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.. _vagrant "mini-mon" development environment: https://github.com/openstack/monasca-vagrant/
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.. _Storyboard: https://storyboard.openstack.org
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