If serverTeamRemover removes a team before machineTeamRemover brings
the machine team number down to the desired number, DD may create a new
team (due to teams removed by serverTeamRemover), which may be removed
later by machineTeamRemover. This causes unnnecessary extra data movement.
Change to remove machine team with most machine teams, using the same
logic as the serverTeamRemover.
The featue is guarded by TR_FLAG_REMOVE_MT_WITH_MOST_TEAMS knob.
time checked on the proxy should be less than the time waited by the master to account for clock speed differences
setting REQUIRED_MIN_RECOVERY_DURATION and ENFORCED_MIN_RECOVERY_DURATION to 0 will go back to the old behavior
Formerly, they would prefer to peek from the primary's logs. Testing of
a failed region rejoining the cluster revealed that this becomes quite a
strain on the primary logs when extremely large volumes of peek requests
are coming from the Log Routers. It happens that we have satellites
that contain the same mutations with Log Router tags, that have no other
peeking load, so we can prefer to use the satellite to peek rather than
the primary to distribute load across TLogs better.
Unfortunately, this revealed a latent bug in how tagged mutations in the
KnownCommittedVersion->RecoveryVersion gap were copied across
generations when the number of log router tags were decreased.
Satellite TLogs would be assigned log router tags using the
team-building based logic in getPushLocations(), whereas TLogs would
internally re-index tags according to tag.id%logRouterTags. This
mismatch would mean that we could have:
Log0 -2:0 ----- -2:0 Log 0
Log1 -2:1 \
>--- -2:1,-2:0 (-2:2 mod 2 becomes -2:0) Log 1
Log2 -2:2 /
And now we have data that's tagged as -2:0 on a TLog that's not the
preferred location for -2:0, and therefore a BestLocationOnly cursor
would miss the mutations.
This was never noticed before, as we never
used a satellite as a preferred location to peek from. Merge cursors
always peek from all locations, and thus a peek for -2:0 that needed
data from the satellites would have gone to both TLogs and merged the
results.
We now take this mod-based re-indexing into account when assigning which
TLogs need to recover which tags from the previous generation, to make
sure that tag.id%logRouterTags always results in the assigned TLog being
the preferred location.
Unfortunately, previously existing will potentially have existing
satellites with log router tags indexed incorrectly, so this transition
needs to be gated on a `log_version` transition. Old LogSets will have
an old LogVersion, and we won't prefer the sattelite for peeking. Log
Sets post-6.2 (opt-in) or post-6.3 (default) will be indexed correctly,
and therefore we can safely offload peeking onto the satellites.
- ignorePopDeadline to have highier limit in simulator
to accommdate for the buggify delays and make snapshot succeed.
- introduce a new knob for auto resetting the disabling of tlog pop
A.J. Beamon