Change Details

This is part of annual plan for FY 25-26. Commons database has grown to an extremely large size (2TB) and we have no choice but to split it. The most cost-benefit efficient way is to move the links tables to a dedicated cluster (x4) which would cut its size to half. These tables must be moved to x4: - linktarget - externallinks - pagelinks - templatelinks - categorylinks - collation - imagelinks - globalimagelinks This can be done via introducing a new core virtual domain (`virtual-links`) and then migrating queries. Any query that join with page or other tables must be split to be two queries hitting different connections and if not possible, it should be done in a different way (e.g. {T309738}) or gets disabled in commons. We need to set up back ups and wikireplicas too.

This is part of annual plan for FY 25-26. Commons database has grown to an extremely large size (2TB) and we have no choice but to split it. The most cost-benefit efficient way is to move the links tables to a dedicated cluster (x4) which would cut its size to half. These tables must be moved to x4: - linktarget - externallinks - pagelinks - templatelinks - categorylinks - collation - imagelinks - globalimagelinks This can be done via introducing a new core virtual domain (`virtual-links`) and then migrating queries. Any query that join with page or other tables must be split to be two queries hitting different connections and if not possible, it should be done in a different way (e.g. {T309738}) or gets disabled in commons. We need to set up back ups and wikireplicas too. For now, we should assume `page` table will exist in both databases. Depending on how many cases directly join and not easy to split, we could consider having page table being shared.

This is part of annual plan for FY 25-26. Commons database has grown to an extremely large size (2TB) and we have no choice but to split it. The most cost-benefit efficient way is to move the links tables to a dedicated cluster (x4) which would cut its size to half. These tables must be moved to x4: - linktarget - externallinks - pagelinks - templatelinks - categorylinks - collation - imagelinks - globalimagelinks This can be done via introducing a new core virtual domain (`virtual-links`) and then migrating queries. Any query that join with page or other tables must be split to be two queries hitting different connections and if not possible, it should be done in a different way (e.g. {T309738}) or gets disabled in commons. We need to set up back ups and wikireplicas too. For now, we should assume `page` table will exist in both databases. Depending on how many cases directly join and not easy to split, we could consider having page table being shared.