[kudu-CR] WIP: tie log retention to consensus watermarks
Kudu Jenkins has posted comments on this change. Change subject: WIP: tie log retention to consensus watermarks .. Patch Set 4: Build Started http://104.196.14.100/job/kudu-gerrit/3264/ -- To view, visit http://gerrit.cloudera.org:8080/4177 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12 Gerrit-PatchSet: 4 Gerrit-Project: kudu Gerrit-Branch: master Gerrit-Owner: Todd Lipcon Gerrit-Reviewer: David Ribeiro Alves Gerrit-Reviewer: Kudu Jenkins Gerrit-Reviewer: Mike Percy Gerrit-Reviewer: Todd Lipcon Gerrit-HasComments: No
[kudu-CR] WIP: tie log retention to consensus watermarks
Hello Kudu Jenkins, I'd like you to reexamine a change. Please visit http://gerrit.cloudera.org:8080/4177 to look at the new patch set (#4). Change subject: WIP: tie log retention to consensus watermarks .. WIP: tie log retention to consensus watermarks This changes the calculation of log retention to consult consensus. Consensus returns a struct which indicates the watermark necessary for durability (the committed index) as well as the watermark necessary to catch up other peers. This replaces the old single "must be retained" watermark that the log GC code used before. The new struct is passed down into the log, and we use the following policy: - we always maintain any logs necessary for durability - beyond that, we try to retain logs to catch up lagging peers, however we never maintain more than --log_max_segments_to_retain (a new configuration) I removed the old flag --log_min_seconds_to_retain, since its main purpose was for dealing with lagging peers, and that is now handled by directly consulting consensus. The one tricky bit of the policy is that, even though the peer catch-up figures into log retention, we do _not_ want it to impact the calculation of flush priority. In other words, even if the user is OK retaining 10GB of logs to catch up trailing peers, they probably still want to flush more aggressively than that so they can avoid very long startup times. So, the peer-based watermark is not used during the mapping of log anchors to retention amounts. Note that the above is only relevant once we have implemented KUDU-38: we currently will replay all of the retained logs even though we are aggressively flushing to keep the durability-related retention bounded. In practice, even without KUDU-38, this patch shouldn't have a large negative effect on restart times. In fact, in many cases it can _improve_ startup times, because in most steady workloads we don't have peers that are extremely far behind. Our log retention only increases in those cases, and only on those tablets which have a lagging follower. For other tablets, the new retention policies actually serve to reduce the number of retained segments, so if there are no laggy peers, we'll start up faster. Manually tested for now as follows: - started a three-node cluster (locally), set to roll logs at 1MB segments, but otherwise default - started an insert workload against a single-tablet table - I could see that the three servers were maintaining 2 WAL segments in their WAL directory. - I kill -STOPped a random server while continuing to insert. I saw that the WALs in this tablet server's directory froze as is (obviously), and the other two kept rolling. However, because of this change, the other servers started retaining wals starting from the point where I had stopped the follower. - If I let the insert workload continue, the live servers kept rolling up until they had 10 segments (default --log_max_segments_to_retain) at which point they dropped the oldest log. - I verified that, during this period while the extra segments were retained, the servers continued to flush frequently so that their recovery time would be bounded. - I also verified that, if I un-paused the follower before the others had evicted it, it was able to catch up, at which point the other servers GCed those extra logs they had been retaining. The above scenario is also tested through modifications to RaftConsensusITest.TestCatchupAfterOpsEvicted and various log-test test cases. Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12 --- M src/kudu/consensus/consensus.h M src/kudu/consensus/consensus.proto M src/kudu/consensus/consensus_peers-test.cc M src/kudu/consensus/consensus_queue-test.cc M src/kudu/consensus/consensus_queue.cc M src/kudu/consensus/consensus_queue.h M src/kudu/consensus/log-test-base.h M src/kudu/consensus/log-test.cc M src/kudu/consensus/log.cc M src/kudu/consensus/log.h M src/kudu/consensus/log_reader.cc M src/kudu/consensus/log_reader.h M src/kudu/consensus/raft_consensus-test.cc M src/kudu/consensus/raft_consensus.cc M src/kudu/consensus/raft_consensus.h M src/kudu/consensus/raft_consensus_quorum-test.cc M src/kudu/integration-tests/external_mini_cluster_fs_inspector.cc M src/kudu/integration-tests/external_mini_cluster_fs_inspector.h M src/kudu/integration-tests/raft_consensus-itest.cc M src/kudu/tablet/tablet_peer-test.cc M src/kudu/tablet/tablet_peer.cc M src/kudu/tablet/tablet_peer.h 22 files changed, 326 insertions(+), 335 deletions(-) git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/77/4177/4 -- To view, visit http://gerrit.cloudera.org:8080/4177 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: newpatchset Gerrit-Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12 Gerrit-PatchSet: 4 Gerrit-Project: kudu Gerrit-Branch: master Gerrit-Owner: Todd Lipcon Gerrit-Reviewer: David Ribei
[kudu-CR] WIP: tie log retention to consensus watermarks
Kudu Jenkins has posted comments on this change. Change subject: WIP: tie log retention to consensus watermarks .. Patch Set 3: Build Started http://104.196.14.100/job/kudu-gerrit/3263/ -- To view, visit http://gerrit.cloudera.org:8080/4177 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12 Gerrit-PatchSet: 3 Gerrit-Project: kudu Gerrit-Branch: master Gerrit-Owner: Todd Lipcon Gerrit-Reviewer: David Ribeiro Alves Gerrit-Reviewer: Kudu Jenkins Gerrit-Reviewer: Mike Percy Gerrit-Reviewer: Todd Lipcon Gerrit-HasComments: No
[kudu-CR] WIP: tie log retention to consensus watermarks
Hello Kudu Jenkins, I'd like you to reexamine a change. Please visit http://gerrit.cloudera.org:8080/4177 to look at the new patch set (#3). Change subject: WIP: tie log retention to consensus watermarks .. WIP: tie log retention to consensus watermarks This changes the calculation of log retention to consult consensus. Consensus returns a struct which indicates the watermark necessary for durability (the committed index) as well as the watermark necessary to catch up other peers. This replaces the old single "must be retained" watermark that the log GC code used before. The new struct is passed down into the log, and we use the following policy: - we always maintain any logs necessary for durability - beyond that, we try to retain logs to catch up lagging peers, however we never maintain more than --log_max_segments_to_retain (a new configuration) I removed the old flag --log_min_seconds_to_retain, since its main purpose was for dealing with lagging peers, and that is now handled by directly consulting consensus. The one tricky bit of the policy is that, even though the peer catch-up figures into log retention, we do _not_ want it to impact the calculation of flush priority. In other words, even if the user is OK retaining 10GB of logs to catch up trailing peers, they probably still want to flush more aggressively than that so they can avoid very long startup times. So, the peer-based watermark is not used during the mapping of log anchors to retention amounts. Note that the above is only relevant once we have implemented KUDU-38: we currently will replay all of the retained logs even though we are aggressively flushing to keep the durability-related retention bounded. In practice, even without KUDU-38, this patch shouldn't have a large negative effect on restart times. In fact, in many cases it can _improve_ startup times, because in most steady workloads we don't have peers that are extremely far behind. Our log retention only increases in those cases, and only on those tablets which have a lagging follower. For other tablets, the new retention policies actually serve to reduce the number of retained segments, so if there are no laggy peers, we'll start up faster. Manually tested for now as follows: - started a three-node cluster (locally), set to roll logs at 1MB segments, but otherwise default - started an insert workload against a single-tablet table - I could see that the three servers were maintaining 2 WAL segments in their WAL directory. - I kill -STOPped a random server while continuing to insert. I saw that the WALs in this tablet server's directory froze as is (obviously), and the other two kept rolling. However, because of this change, the other servers started retaining wals starting from the point where I had stopped the follower. - If I let the insert workload continue, the live servers kept rolling up until they had 10 segments (default --log_max_segments_to_retain) at which point they dropped the oldest log. - I verified that, during this period while the extra segments were retained, the servers continued to flush frequently so that their recovery time would be bounded. - I also verified that, if I un-paused the follower before the others had evicted it, it was able to catch up, at which point the other servers GCed those extra logs they had been retaining. WIP because this needs some automated tests for the above behavior Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12 --- M src/kudu/consensus/consensus.h M src/kudu/consensus/consensus.proto M src/kudu/consensus/consensus_peers-test.cc M src/kudu/consensus/consensus_queue-test.cc M src/kudu/consensus/consensus_queue.cc M src/kudu/consensus/consensus_queue.h M src/kudu/consensus/log-test-base.h M src/kudu/consensus/log-test.cc M src/kudu/consensus/log.cc M src/kudu/consensus/log.h M src/kudu/consensus/log_reader.cc M src/kudu/consensus/log_reader.h M src/kudu/consensus/raft_consensus-test.cc M src/kudu/consensus/raft_consensus.cc M src/kudu/consensus/raft_consensus.h M src/kudu/integration-tests/raft_consensus-itest.cc M src/kudu/tablet/tablet_peer-test.cc M src/kudu/tablet/tablet_peer.cc M src/kudu/tablet/tablet_peer.h 19 files changed, 251 insertions(+), 319 deletions(-) git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/77/4177/3 -- To view, visit http://gerrit.cloudera.org:8080/4177 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: newpatchset Gerrit-Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12 Gerrit-PatchSet: 3 Gerrit-Project: kudu Gerrit-Branch: master Gerrit-Owner: Todd Lipcon Gerrit-Reviewer: David Ribeiro Alves Gerrit-Reviewer: Kudu Jenkins Gerrit-Reviewer: Mike Percy Gerrit-Reviewer: Todd Lipcon
[kudu-CR] WIP: tie log retention to consensus watermarks
Todd Lipcon has posted comments on this change. Change subject: WIP: tie log retention to consensus watermarks .. Patch Set 1: ok, new patch is largely cleaned up, though still planning on adding a test or two. Worth reviewing, though. -- To view, visit http://gerrit.cloudera.org:8080/4177 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12 Gerrit-PatchSet: 1 Gerrit-Project: kudu Gerrit-Branch: master Gerrit-Owner: Todd Lipcon Gerrit-Reviewer: David Ribeiro Alves Gerrit-Reviewer: Kudu Jenkins Gerrit-Reviewer: Mike Percy Gerrit-Reviewer: Todd Lipcon Gerrit-HasComments: No
[kudu-CR] WIP: tie log retention to consensus watermarks
Hello Kudu Jenkins, I'd like you to reexamine a change. Please visit http://gerrit.cloudera.org:8080/4177 to look at the new patch set (#2). Change subject: WIP: tie log retention to consensus watermarks .. WIP: tie log retention to consensus watermarks This changes the calculation of log retention to consult consensus. Consensus returns a struct which indicates the watermark necessary for durability (the committed index) as well as the watermark necessary to catch up other peers. This replaces the old single "must be retained" watermark that the log GC code used before. The new struct is passed down into the log, and we use the following policy: - we always maintain any logs necessary for durability - beyond that, we try to retain logs to catch up lagging peers, however we never maintain more than --log_max_segments_to_retain (a new configuration) I removed the old flag --log_min_seconds_to_retain, since its main purpose was for dealing with lagging peers, and that is now handled by directly consulting consensus. The one tricky bit of the policy is that, even though the peer catch-up figures into log retention, we do _not_ want it to impact the calculation of flush priority. In other words, even if the user is OK retaining 10GB of logs to catch up trailing peers, they probably still want to flush more aggressively than that so they can avoid very long startup times. So, the peer-based watermark is not used during the mapping of log anchors to retention amounts. Note that the above is only relevant once we have implemented KUDU-38: we currently will replay all of the retained logs even though we are aggressively flushing to keep the durability-related retention bounded. In practice, even without KUDU-38, this patch shouldn't have a large negative effect on restart times. In fact, in many cases it can _improve_ startup times, because in most steady workloads we don't have peers that are extremely far behind. Our log retention only increases in those cases, and only on those tablets which have a lagging follower. For other tablets, the new retention policies actually serve to reduce the number of retained segments, so if there are no laggy peers, we'll start up faster. Manually tested for now as follows: - started a three-node cluster (locally), set to roll logs at 1MB segments, but otherwise default - started an insert workload against a single-tablet table - I could see that the three servers were maintaining 2 WAL segments in their WAL directory. - I kill -STOPped a random server while continuing to insert. I saw that the WALs in this tablet server's directory froze as is (obviously), and the other two kept rolling. However, because of this change, the other servers started retaining wals starting from the point where I had stopped the follower. - If I let the insert workload continue, the live servers kept rolling up until they had 10 segments (default --log_max_segments_to_retain) at which point they dropped the oldest log. - I verified that, during this period while the extra segments were retained, the servers continued to flush frequently so that their recovery time would be bounded. - I also verified that, if I un-paused the follower before the others had evicted it, it was able to catch up, at which point the other servers GCed those extra logs they had been retaining. WIP because this needs some automated tests for the above behavior Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12 --- M src/kudu/consensus/consensus.h M src/kudu/consensus/consensus.proto M src/kudu/consensus/consensus_queue-test.cc M src/kudu/consensus/consensus_queue.cc M src/kudu/consensus/consensus_queue.h M src/kudu/consensus/log-test-base.h M src/kudu/consensus/log-test.cc M src/kudu/consensus/log.cc M src/kudu/consensus/log.h M src/kudu/consensus/log_reader.cc M src/kudu/consensus/log_reader.h M src/kudu/consensus/raft_consensus-test.cc M src/kudu/consensus/raft_consensus.cc M src/kudu/consensus/raft_consensus.h M src/kudu/integration-tests/raft_consensus-itest.cc M src/kudu/tablet/tablet_peer-test.cc M src/kudu/tablet/tablet_peer.cc M src/kudu/tablet/tablet_peer.h 18 files changed, 248 insertions(+), 316 deletions(-) git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/77/4177/2 -- To view, visit http://gerrit.cloudera.org:8080/4177 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: newpatchset Gerrit-Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12 Gerrit-PatchSet: 2 Gerrit-Project: kudu Gerrit-Branch: master Gerrit-Owner: Todd Lipcon Gerrit-Reviewer: David Ribeiro Alves Gerrit-Reviewer: Kudu Jenkins Gerrit-Reviewer: Mike Percy Gerrit-Reviewer: Todd Lipcon
[kudu-CR] WIP: tie log retention to consensus watermarks
Kudu Jenkins has posted comments on this change. Change subject: WIP: tie log retention to consensus watermarks .. Patch Set 2: Build Started http://104.196.14.100/job/kudu-gerrit/3262/ -- To view, visit http://gerrit.cloudera.org:8080/4177 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12 Gerrit-PatchSet: 2 Gerrit-Project: kudu Gerrit-Branch: master Gerrit-Owner: Todd Lipcon Gerrit-Reviewer: David Ribeiro Alves Gerrit-Reviewer: Kudu Jenkins Gerrit-Reviewer: Mike Percy Gerrit-Reviewer: Todd Lipcon Gerrit-HasComments: No
[kudu-CR] WIP: tie log retention to consensus watermarks
Todd Lipcon has posted comments on this change.
Change subject: WIP: tie log retention to consensus watermarks
..
Patch Set 1:
(3 comments)
just responding to comments. will work on the TODOs in the patch and add tests.
http://gerrit.cloudera.org:8080/#/c/4177/1//COMMIT_MSG
Commit Message:
Line 60: WIP because this needs some automated tests for the above behavior, and
> would also be good to get an idea on what is the impact on startup. our boo
will add a comment to the commit message about this.
http://gerrit.cloudera.org:8080/#/c/4177/1/src/kudu/consensus/log.cc
File src/kudu/consensus/log.cc:
Line 650: rem_segs <= FLAGS_log_max_segments_to_retain) {
> idea (possibly unrelated to this patch), instead of a max segments to retai
hesitant to do it percentage-wise, because it's not always obvious how that
plays with shared drive usage. ie is it "20% of the total drive?" or "20% of
the space that you want Kudu to be using"? I do agree that size-wise is better
than a segment count, and it should probably be global across all tablets, not
a per-tablet setting.
If you don't mind, I'll try to tackle this as part of KUDU-1567. I did mark the
new 'max_segments_to_retain' as experimental so that we can break it.
http://gerrit.cloudera.org:8080/#/c/4177/1/src/kudu/consensus/raft_consensus.h
File src/kudu/consensus/raft_consensus.h:
Line 173: log::RetentionIndexes GetLogRetention() override;
> rename to GetRetentionIndexes?
Done
--
To view, visit http://gerrit.cloudera.org:8080/4177
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings
Gerrit-MessageType: comment
Gerrit-Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12
Gerrit-PatchSet: 1
Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-Owner: Todd Lipcon
Gerrit-Reviewer: David Ribeiro Alves
Gerrit-Reviewer: Kudu Jenkins
Gerrit-Reviewer: Mike Percy
Gerrit-Reviewer: Todd Lipcon
Gerrit-HasComments: Yes
[kudu-CR] WIP: tie log retention to consensus watermarks
David Ribeiro Alves has posted comments on this change.
Change subject: WIP: tie log retention to consensus watermarks
..
Patch Set 1:
(3 comments)
partial review. back on it later (may wait a little bit to see if it stops
being a WIP)
http://gerrit.cloudera.org:8080/#/c/4177/1//COMMIT_MSG
Commit Message:
Line 60: WIP because this needs some automated tests for the above behavior, and
would also be good to get an idea on what is the impact on startup. our
bootstrap times already take a pretty long time, but this might mean they
increase by a lot. at the very least this would help prioritize kudu-38
http://gerrit.cloudera.org:8080/#/c/4177/1/src/kudu/consensus/log.cc
File src/kudu/consensus/log.cc:
Line 650: rem_segs <= FLAGS_log_max_segments_to_retain) {
idea (possibly unrelated to this patch), instead of a max segments to retain
flag should we have a "max_percentage_of_drive_space" or something like that
flag?
http://gerrit.cloudera.org:8080/#/c/4177/1/src/kudu/consensus/raft_consensus.h
File src/kudu/consensus/raft_consensus.h:
Line 173: log::RetentionIndexes GetLogRetention() override;
rename to GetRetentionIndexes?
--
To view, visit http://gerrit.cloudera.org:8080/4177
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings
Gerrit-MessageType: comment
Gerrit-Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12
Gerrit-PatchSet: 1
Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-Owner: Todd Lipcon
Gerrit-Reviewer: David Ribeiro Alves
Gerrit-Reviewer: Kudu Jenkins
Gerrit-Reviewer: Mike Percy
Gerrit-HasComments: Yes
[kudu-CR] WIP: tie log retention to consensus watermarks
Kudu Jenkins has posted comments on this change. Change subject: WIP: tie log retention to consensus watermarks .. Patch Set 1: Build Started http://104.196.14.100/job/kudu-gerrit/3156/ -- To view, visit http://gerrit.cloudera.org:8080/4177 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12 Gerrit-PatchSet: 1 Gerrit-Project: kudu Gerrit-Branch: master Gerrit-Owner: Todd Lipcon Gerrit-Reviewer: Kudu Jenkins Gerrit-Reviewer: Mike Percy Gerrit-HasComments: No
[kudu-CR] WIP: tie log retention to consensus watermarks
Hello Mike Percy, I'd like you to do a code review. Please visit http://gerrit.cloudera.org:8080/4177 to review the following change. Change subject: WIP: tie log retention to consensus watermarks .. WIP: tie log retention to consensus watermarks This changes the calculation of log retention to consult consensus. Consensus returns a struct which indicates the watermark necessary for durability (the committed index) as well as the watermark necessary to catch up other peers. This replaces the old single "must be retained" watermark that the log GC code used before. The new struct is passed down into the log, and we use the following policy: - we always maintain any logs necessary for durability - beyond that, we try to retain logs to catch up lagging peers, however we never maintain more than --log_max_segments_to_retain (a new configuration) I removed the old flag --log_min_seconds_to_retain, since its main purpose was for dealing with lagging peers, and that is now handled by directly consulting consensus. The one tricky bit of the policy is that, even though the peer catch-up figures into log retention, we do _not_ want it to impact the calculation of flush priority. In other words, even if the user is OK retaining 10GB of logs to catch up trailing peers, they probably still want to flush more aggressively than that so they can avoid very long startup times. So, the peer-based watermark is not used during the mapping of log anchors to retention amounts. Note that the above is only relevant once we have implemented KUDU-38: we currently will replay all of the retained logs even though we are aggressively flushing to keep the durability-related retention bounded. Manually tested for now as follows: - started a three-node cluster (locally), set to roll logs at 1MB segments, but otherwise default - started an insert workload against a single-tablet table - I could see that the three servers were maintaining 2 WAL segments in their WAL directory. - I kill -STOPped a random server while continuing to insert. I saw that the WALs in this tablet server's directory froze as is (obviously), and the other two kept rolling. However, because of this change, the other servers started retaining wals starting from the point where I had stopped the follower. - If I let the insert workload continue, the live servers kept rolling up until they had 10 segments (default --log_max_segments_to_retain) at which point they dropped the oldest log. - I verified that, during this period while the extra segments were retained, the servers continued to flush frequently so that their recovery time would be bounded. - I also verified that, if I un-paused the follower before the others had evicted it, it was able to catch up, at which point the other servers GCed those extra logs they had been retaining. WIP because this needs some automated tests for the above behavior, and need to sweep for comments to update, clean-up, etc. Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12 --- M src/kudu/consensus/consensus.h M src/kudu/consensus/consensus.proto M src/kudu/consensus/consensus_queue-test.cc M src/kudu/consensus/consensus_queue.cc M src/kudu/consensus/consensus_queue.h M src/kudu/consensus/log-test-base.h M src/kudu/consensus/log-test.cc M src/kudu/consensus/log.cc M src/kudu/consensus/log.h M src/kudu/consensus/log_reader.cc M src/kudu/consensus/log_reader.h M src/kudu/consensus/raft_consensus.cc M src/kudu/consensus/raft_consensus.h M src/kudu/integration-tests/raft_consensus-itest.cc M src/kudu/tablet/tablet_peer-test.cc M src/kudu/tablet/tablet_peer.cc M src/kudu/tablet/tablet_peer.h 17 files changed, 193 insertions(+), 225 deletions(-) git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/77/4177/1 -- To view, visit http://gerrit.cloudera.org:8080/4177 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: newchange Gerrit-Change-Id: Icfc071270510f3dc3c65f88d615e93c6ffb26b12 Gerrit-PatchSet: 1 Gerrit-Project: kudu Gerrit-Branch: master Gerrit-Owner: Todd Lipcon Gerrit-Reviewer: Mike Percy
