Change Details

Steps to drop the columns: - Make sure maintenance has finished and data has been migrated - Change PK: ``` ALTER TABLE pagelinks DROP PRIMARY KEY, ADD PRIMARY KEY (`pl_from`, `pl_target_id`); ``` - Stop writing to the old columns - Make communications if needed - Drop the columns and indexes: ``` ALTER TABLE pagelinks DROP COLUMN pl_namespace, DROP COLUMN pl_title; DROP INDEX pl_namespace ON pagelinks; DROP INDEX pl_backlinks_namespace ON pagelinks; optimize table pagelinks; ``` Progress of PK change: [] s1: Done everywhere except dc masters [] s2: NOT YET [] s3: Done everywhere except eqiad master [x] s4: Done [x] s5: Done [] s6: Done everywhere except eqiad master [] s7: Done everywhere except eqiad master [] s8: Done everywhere except dc masters [] labtestwiki Progress of dropping the columns: [] s1: NOT YET [] s2: NOT YET [] s3: NOT YET [] s4: Done everywhere except dc masters [] s5: NOT YET [] s6: NOT YET [] s7: NOT YET [] s8: NOT YET [] labtestwiki Impact: - Changing PK: - s1: Drops ~150GB from each replica - s5: Drops ~80GB from each replica. - s3: 150-160GB dropped from each replica. - s4: ~90GB dropped from each replica. - s6: ~90GB dropped from each replica. - s7: ~170GB dropped from each replica (https://grafana.wikimedia.org/d/000000377/host-overview?orgId=1&var-server=db2121&var-datasource=thanos&var-cluster=mysql&viewPanel=28&from=1711369820705&to=1711461258205) - s8: ~110GB dropped from each replica. - Dropping the columns - s4: ~80GB

Steps to drop the columns: - Make sure maintenance has finished and data has been migrated - Change PK: ``` ALTER TABLE pagelinks DROP PRIMARY KEY, ADD PRIMARY KEY (`pl_from`, `pl_target_id`); ``` - Stop writing to the old columns - Make communications if needed - Drop the columns and indexes: ``` ALTER TABLE pagelinks DROP COLUMN pl_namespace, DROP COLUMN pl_title; DROP INDEX pl_namespace ON pagelinks; DROP INDEX pl_backlinks_namespace ON pagelinks; optimize table pagelinks; ``` Progress of PK change: [] s1: Done everywhere except dc masters [] s2: NOT YET [x] s3: Done [x] s4: Done [x] s5: Done [] s6: Done everywhere except eqiad master [] s7: Done everywhere except eqiad master [] s8: Done everywhere except dc masters [] labtestwiki Progress of dropping the columns: [] s1: NOT YET [] s2: NOT YET [] s3: NOT YET [] s4: Done everywhere except dc masters [] s5: NOT YET [] s6: NOT YET [] s7: NOT YET [] s8: NOT YET [] labtestwiki Impact: - Changing PK: - s1: Drops ~150GB from each replica - s5: Drops ~80GB from each replica. - s3: 150-160GB dropped from each replica. - s4: ~90GB dropped from each replica. - s6: ~90GB dropped from each replica. - s7: ~170GB dropped from each replica (https://grafana.wikimedia.org/d/000000377/host-overview?orgId=1&var-server=db2121&var-datasource=thanos&var-cluster=mysql&viewPanel=28&from=1711369820705&to=1711461258205) - s8: ~110GB dropped from each replica. - Dropping the columns - s4: ~80GB

Steps to drop the columns: - Make sure maintenance has finished and data has been migrated - Change PK: ``` ALTER TABLE pagelinks DROP PRIMARY KEY, ADD PRIMARY KEY (`pl_from`, `pl_target_id`); ``` - Stop writing to the old columns - Make communications if needed - Drop the columns and indexes: ``` ALTER TABLE pagelinks DROP COLUMN pl_namespace, DROP COLUMN pl_title; DROP INDEX pl_namespace ON pagelinks; DROP INDEX pl_backlinks_namespace ON pagelinks; optimize table pagelinks; ``` Progress of PK change: [] s1: Done everywhere except dc masters [] s2: NOT YET [x] s3: Done everywhere except eqiad mastere [x] s4: Done [x] s5: Done [] s6: Done everywhere except eqiad master [] s7: Done everywhere except eqiad master [] s8: Done everywhere except dc masters [] labtestwiki Progress of dropping the columns: [] s1: NOT YET [] s2: NOT YET [] s3: NOT YET [] s4: Done everywhere except dc masters [] s5: NOT YET [] s6: NOT YET [] s7: NOT YET [] s8: NOT YET [] labtestwiki Impact: - Changing PK: - s1: Drops ~150GB from each replica - s5: Drops ~80GB from each replica. - s3: 150-160GB dropped from each replica. - s4: ~90GB dropped from each replica. - s6: ~90GB dropped from each replica. - s7: ~170GB dropped from each replica (https://grafana.wikimedia.org/d/000000377/host-overview?orgId=1&var-server=db2121&var-datasource=thanos&var-cluster=mysql&viewPanel=28&from=1711369820705&to=1711461258205) - s8: ~110GB dropped from each replica. - Dropping the columns - s4: ~80GB