Next steps:
- Merge the schema change patch: https://gerrit.wikimedia.org/r/#/q/If5c137f6
- Deploy the schema change to all wikis: T153182
- Merge the "populate field" patch: https://gerrit.wikimedia.org/r/#/q/I971edf01
- Wait for the "populate field" patch to be deployed to all wikis.
- (optional) Schema change to drop the default on the el_index_60 column: T197891
- Run maintenance/populateExternallinksIndex60.php: (didn't file a separate task)
- Merge the "start using field" patch: https://gerrit.wikimedia.org/r/#/q/I84d224ef
-
Announce in tech news that Special:LinkSearch results might be incomplete in between when the above patch is deployed to the wiki and the maintenance script below is run on the wiki.Missed the window. Oh well. - Run maintenance/refreshExternallinksIndex.php: T209373
Crazy limit offsets like this are showing up in slow query logs for enwiki:
SELECT /* ApiQueryExtLinksUsage::run */ page_id,page_namespace,page_title,el_to FROM `page`,`externallinks` WHERE (page_id=el_from) AND (el_index LIKE 'http://gov.nih.nlm.ncbi.%' ) LIMIT 768500,501;
By itself it's not too bad, < 10 seconds, but they're appearing in spikes presumably from something automated and causing concurrency issues.
Suggest disallowing such page offsets or redesigning the pagination method.