Overview of the Issue
On a PRIMARY tablet, the lag throttler collects the identities of replicas (or otherwise probe-worthy tablets) every 10 seconds, and routinely queries those tablets.
When demoted to REPLICA, e.g. on a PlannedReparentShard, the throttler no longer collects identities of replicas. But there's also no mechanism to remove its pre-existing history of replicas. The demoted throttler therefore continues probing its replicas.
Reproduction Steps
Run PRIMARY and REPLICA, enable the lag throttler. run PlannetReparentShard, observe that the demoted tablet still hits CheckThrottler on the new PRIMARY.
Binary Version
Operating System and Environment details
Log Fragments
No response
Overview of the Issue
On a
PRIMARYtablet, the lag throttler collects the identities of replicas (or otherwise probe-worthy tablets) every 10 seconds, and routinely queries those tablets.When demoted to
REPLICA, e.g. on aPlannedReparentShard, the throttler no longer collects identities of replicas. But there's also no mechanism to remove its pre-existing history of replicas. The demoted throttler therefore continues probing its replicas.Reproduction Steps
Run
PRIMARYandREPLICA, enable the lag throttler. runPlannetReparentShard, observe that the demoted tablet still hitsCheckThrottleron the newPRIMARY.Binary Version
Operating System and Environment details
Log Fragments
No response