//This is still a draft//
Prerequisites:
- [x] T306422: translatewiki.net is upgraded to elasticsearch 6.8.23 and all its indices have been recreated using this elasticsearch version
- [x] T289135: all elasticsearch nodes are re-imaged with bullseye
- [x] T301131: elasticsearch analyzers are tested and no blockers are found
- [x] T218994: no more deprecation warnings are reported
- [x] check that all indices hosted on all wmf elasticsearch clusters are reindexed with elasticsearch 6
- [x] T307931 all cindy tests are passing on the es710 branch
- [x] The cirrus master branch is able to write to and create indices against elasticsearch 7.10.2 (https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CirrusSearch/+/793482)
- [x] The cirrus es710 branch is able to write to and create indices against elasticsearch 6.8.23 (https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CirrusSearch/+/793522)
- [x] Prepare a patch to mw-config able to switch all search traffic (search/morelike/ttm) to one specific DC depending on the current mw version (e.g. https://gerrit.wikimedia.org/r/c/operations/mediawiki-config/+/291257) and active any BC option required (e.g. using ES6CompatTransportWrapper) - patch at https://gerrit.wikimedia.org/r/c/operations/mediawiki-config/+/824787
- [x] T313434: ApiFeatureUsage is prepared for transition
- [x] relforge is running elasticsearch 7.10.2
- [x] All cirrus indices in prod clusters have mapping type of _doc
Unknowns:
- Starting week: Aug 29, 2022
- Train version: Expecting 1.39.0-wmf.28 with branch cut on Sept 5.
Once all prerequisites are verified define the week starting date for the rollout:
Plan:
- Week 1
-- [x] Monday: Upgrade cloudelastic to elasticsearch 7.10.2 and verify that updates are flowing properly
-- [x] Tuesday: Merge [[ https://gerrit.wikimedia.org/r/c/operations/puppet/+/815783 | apifeatureusage prep]]. Start the rollout on codfw and monitor updates
-- **After** the branch cut, merge:
--- [x] Merge the es710 branch into master in vendor, CirrusSearch, and Elastica repositories
-- [x] Note the mediawiki version they'll land into and update the mw-config patch (https://gerrit.wikimedia.org/r/c/operations/mediawiki-config/+/824787) with it
-- [x] Add these patches as risky in a comment to the corresponding `deployment blockers` phab task
-- [x] Soon after merging upgrade deployment-prep to elasticsearch 7.10.2 and verify search functions/error logs
-- [] Once codfw is fully upgraded deploy the mw-config patch to switch search traffic based on the mw train version
- Week 2
-- Wait for the train to rollout everywhere and verify search functions/error logs, search traffic will start flowing to codfw as the train rolls forward, be available to releng when syncing wiki groups
- Week 3 (after the expected train version is running everywhere and unlikely to be rolled back)
-- [] Upgrade eqiad to elasticsearch 7.10.2
-- [] Revert the mw-config patch to switch traffic back to eqiad
-- [] Merge [[ https://gerrit.wikimedia.org/r/c/operations/puppet/+/815784 | apifeatureusage template ]]
Things to watch out:
- CirrusSearch maintenance scripts: completion suggester, dump index, saneitizer