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Revision as of 13:37, 16 August 2021 by (clarify what happens if scap canary check fails: the code is *not* automatically rolled back to the last good version)
The term “canary” can describe different things:
- The debug servers, e. g. mwdebug1002, are sometimes called canaries. Changes are often deployed to them via
scap pullbefore deploying them everywhere with
- Scap has the notion of canary hosts: when deploying a change, it will first deploy it to a subset of servers, then pause for a bit and check their error rate. If enough canary servers experience a significantly higher error rate, the deployment is automatically aborted (though the canary servers continue to serve traffic with the deployed code).
- group0 wikis are sometimes called canary wikis. Problems with a new MediaWiki version may be discovered there before they start affecting the bigger wikis.