Change Details

Next steps: [X] Merge the schema change patch: https://gerrit.wikimedia.org/r/#/q/If5c137f6 [x] Deploy the schema change to all wikis: T153182 [X] Merge the "populate field" patch: https://gerrit.wikimedia.org/r/#/q/I971edf01 [X] Wait for the "populate field" patch to be deployed to all wikis. [X] (optional) Schema change to drop the default on the `el_index_60` column: T197891 [X] Run maintenance/populateExternallinksIndex60.php: //(didn't file a separate task)// [X] Merge the "start using field" patch: https://gerrit.wikimedia.org/r/#/q/I84d224ef [X] ~~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: ```lang=sql 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.

Next steps: [X] Merge the schema change patch: https://gerrit.wikimedia.org/r/#/q/If5c137f6 [x] Deploy the schema change to all wikis: T153182 [X] Merge the "populate field" patch: https://gerrit.wikimedia.org/r/#/q/I971edf01 [X] Wait for the "populate field" patch to be deployed to all wikis. [X] (optional) Schema change to drop the default on the `el_index_60` column: T197891 [X] Run maintenance/populateExternallinksIndex60.php: //(didn't file a separate task)// [X] Merge the "start using field" patch: https://gerrit.wikimedia.org/r/#/q/I84d224ef [X] ~~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. [X] Run maintenance/refreshExternallinksIndex.php: T209373 ---- Crazy limit offsets like this are showing up in slow query logs for enwiki: ```lang=sql 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.

Next steps: [X] Merge the schema change patch: https://gerrit.wikimedia.org/r/#/q/If5c137f6 [x] Deploy the schema change to all wikis: T153182 [X] Merge the "populate field" patch: https://gerrit.wikimedia.org/r/#/q/I971edf01 [X] Wait for the "populate field" patch to be deployed to all wikis. [X] (optional) Schema change to drop the default on the `el_index_60` column: T197891 [X] Run maintenance/populateExternallinksIndex60.php: //(didn't file a separate task)// [X] Merge the "start using field" patch: https://gerrit.wikimedia.org/r/#/q/I84d224ef [X] ~~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. [X] Run maintenance/refreshExternallinksIndex.php: T209373 ---- Crazy limit offsets like this are showing up in slow query logs for enwiki: ```lang=sql 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.