835122560f
We're seeing high system load and decreased performance on our
production Gerrit instance. Some research suggests this may be I/O
contention which can be relieved through better caching:
https://groups.google.com/g/repo-discuss/c/7CemrH4lVJE
According to `gerrit show-caches --show-jvm --show-threads` some of
our memory-only caches are already at their default maximums after
only a few days of operation, and one in particular
(changeid_project) has a particularly poor cache hit ratio of 24% at
the moment. Increase changeid_project from the 1024 entry default by
32x (manual tests at 8x approached 50% cache hit), increase projects
by 4x (greater than the number of repos we host for now), and double
the others (groups_bysubgroup, permission_sort) since they still had
reasonable cache hit ratios while full. Also alpha-order the
existing cache overrides in our config for improved maintainability.
This will require a Gerrit service restart to take effect, once the
file update has been deployed.
Change-Id: Ieecd1802ce53cc0d37c68476b94b44cbe36fbd6e
OpenDev System Configuration
This is the machinery that drives the configuration, testing, continuous integration and deployment of services provided by the OpenDev project.
Services are driven by Ansible playbooks and associated roles stored
here. If you are interested in the configuration of a particular
service, starting at playbooks/service-<name>.yaml
will show you how it is configured.
Most services are deployed via containers; many of them are built or
customised in this repository; see docker/.
A small number of legacy services are still configured with Puppet.
Although the act of running puppet on these hosts is managed by Ansible,
the actual core of their orchestration lives in manifests
and modules.
Testing
OpenDev infrastructure runs a complete testing and continuous-integration environment, powered by Zuul.
Any changes to playbooks, roles or containers will trigger jobs to thoroughly test those changes.
Tests run the orchestration for the modified services on test nodes
assigned to the job. After the testing deployment is configured
(validating the basic environment at least starts running), specific
tests are configured in the testinfra directory to validate
functionality.
Continuous Deployment
Once changes are reviewed and committed, they will be applied
automatically to the production hosts. This is done by Zuul jobs running
in the deploy pipeline. At any one time, you may see these
jobs running live on the status page or
you could check historical runs on the pipeline
results (note there is also an opendev-prod-hourly
pipeline, which ensures things like upstream package updates or
certificate renewals are incorporated in a timely fashion).
Contributing
Contributions are welcome!
You do not need any special permissions to make contributions, even those that will affect production services. Your changes will be automatically tested, reviewed by humans and, once accepted, deployed automatically.
Bug fixes or modifications to existing code are great places to start, and you will see the results of your changes in CI testing.
You can develop all the playbooks, roles, containers and testing required for a new service just by uploading a change. Using a similar service as a template is generally a good place to start. If deploying to production will require new compute resources (servers, volumes, etc.) these will have to be deployed by an OpenDev administrator before your code is committed. Thus if you know you will need new resources, it is best to coordinate this before review.
The #opendev IRC channel is the main place for interactive discussion. Feel free to ask any questions and someone will try to help ASAP. The OpenDev meeting is a co-ordinated time to synchronize on infrastructure issues. Issues should be added to the agenda for discussion; even if you can not attend, you can raise your issue and check back on the logs later. There is also the service-discuss mailing list where you are welcome to send queries or questions.
Documentation
The latest documentation is available at https://docs.opendev.org/opendev/system-config/latest/
That documentation is generated from this repository. You can geneate
it yourself with tox -e docs.