(elastic20[61-72]) See T291654 for procurement, T294154 for racking. These 12 refresh hosts are replacing elastic20[25-36].
(elastic20[73-86]) See T299608 for procurement, T299608 for racking. These are 14 new expansion hosts.
Step 1: Set up hieradata
- allocate between psi/omega, keeping rows as balanced as possible
Step 2: Enable cirrus roles
- after completion of this step, the new hosts should have joined the cirrus elasticsearch clusters
Step 3: Prepare to decom old hosts
- set new master configuration - https://phabricator.wikimedia.org/T294805#7473840
- manually ban from cluster
- set new replication master seeds (if masters changed) https://phabricator.wikimedia.org/T294805#7701855
Step 4: Actually decom hosts (elastic20[25-36])
- remove cirrus role and run decom cookbooks; then open decom tickets for dc-op