Hello Marton Greber, Kudu Jenkins,
I'd like you to reexamine a change. Please visit
http://gerrit.cloudera.org:8080/24945
to look at the new patch set (#2).
Change subject: KUDU-3802 add cluster_leader_skew gauge
......................................................................
KUDU-3802 add cluster_leader_skew gauge
The counters on the auto-leader-rebalancer report activity: how many
rounds ran, how many moves were scheduled. They don't report whether
leadership is currently spread unevenly across the cluster, so an
operator can't tell from them whether rebalancing is needed at all.
This changelist adds a cluster_leader_skew gauge on the master, next
to the existing cluster_replica_skew one. It reports the difference in
Raft leader count between the tablet server hosting the most leaders
and the one hosting the fewest.
Tablet servers already track their own leader count in the
num_raft_leaders gauge, so the count only needs to be carried over to
the master. TSHeartbeatRequestPB gains an optional num_raft_leaders
field, and the master stores the last reported value in the
TSDescriptor of the corresponding tablet server.
Both the heartbeat field and the master-side value are optional, so a
tablet server running a version that predates the field is left out of
the calculation rather than counted as hosting no leaders. Counting it
as zero would make it look like the least loaded server in the
cluster, and the gauge would read as high as the maximum leader count
for as long as a rolling upgrade takes.
The new master-test scenario forges heartbeats to check the value of
the gauge, including the case of a tablet server that reports no
count. The new registration-test scenario checks that the count a real
tablet server reports actually reaches the master.
Change-Id: Iec82f841934f4e310509ee1b7156040b3bba5489
---
M src/kudu/integration-tests/registration-test.cc
M src/kudu/master/master-test.cc
M src/kudu/master/master.proto
M src/kudu/master/master_service.cc
M src/kudu/master/ts_descriptor.h
M src/kudu/master/ts_manager.cc
M src/kudu/master/ts_manager.h
M src/kudu/tserver/heartbeater.cc
8 files changed, 190 insertions(+), 0 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/45/24945/2
--
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Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-MessageType: newpatchset
Gerrit-Change-Id: Iec82f841934f4e310509ee1b7156040b3bba5489
Gerrit-Change-Number: 24945
Gerrit-PatchSet: 2
Gerrit-Owner: Gabriella Lotz <[email protected]>
Gerrit-Reviewer: Kudu Jenkins (120)
Gerrit-Reviewer: Marton Greber <[email protected]>
