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Posted to reviews@kudu.apache.org by "Alexey Serbin (Code Review)" <ge...@cloudera.org> on 2020/04/13 23:33:34 UTC

[kudu-CR](branch-1.12.x) [catalog manager] reduce contention in ScopedLeaderSharedLock 

Hello Kudu Jenkins, Andrew Wong,

I'd like you to do a code review. Please visit

    http://gerrit.cloudera.org:8080/15723

to review the following change.


Change subject: [catalog_manager] reduce contention in ScopedLeaderSharedLock
......................................................................

[catalog_manager] reduce contention in ScopedLeaderSharedLock

While troubleshooting one performance issue if running a big cluster
with large number of tables and high rate of ConnectToMaster requests,
in the logs I noticed many reports like the following:

  0323 03:59:31.091198 (+607857us) spinlock_profiling.cc:243]
  Waited 492 ms on lock 0x4cb0960. stack:
    0000000002398852
    0000000000ad8c69
    0000000000aa62ba
    000000000221aaa8
    ...

which translates into
    (anonymous namespace)::SubmitSpinLockProfileData()
    master::CatalogManager::ScopedLeaderSharedLock::ScopedLeaderSharedLock()
    master::MasterServiceImpl::ConnectToMaster()
    rpc::GeneratedServiceIf::Handle()
    ...

From the code it became apparent that the lock in question was
  std::lock_guard<simple_spinlock> l(catalog_->state_lock_);
in ScopedLeaderSharedLock() constructor.

As far as I can see, there is no need to access master's Raft consensus
information (which itself might wait on its internal locks if there is
corresponding Raft-consensus activity) under the catalog's state lock.

This patch shortens the critical section with catalog's state lock held
when constructing CatalogManager::ScopedLeaderSharedLock instance.

Change-Id: I3b2e6866a8a0d5bda9e2b1f01e0668427de60868
Reviewed-on: http://gerrit.cloudera.org:8080/15698
Reviewed-by: Andrew Wong <aw...@cloudera.com>
Tested-by: Kudu Jenkins
(cherry picked from commit 14912a1fd78ba7cf4d62bf934ae64d6f6f229ee6)
---
M src/kudu/master/catalog_manager.cc
1 file changed, 11 insertions(+), 7 deletions(-)



  git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/23/15723/1
-- 
To view, visit http://gerrit.cloudera.org:8080/15723
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-Project: kudu
Gerrit-Branch: branch-1.12.x
Gerrit-MessageType: newchange
Gerrit-Change-Id: I3b2e6866a8a0d5bda9e2b1f01e0668427de60868
Gerrit-Change-Number: 15723
Gerrit-PatchSet: 1
Gerrit-Owner: Alexey Serbin <as...@cloudera.com>
Gerrit-Reviewer: Andrew Wong <aw...@cloudera.com>
Gerrit-Reviewer: Kudu Jenkins (120)

[kudu-CR](branch-1.12.x) [catalog manager] reduce contention in ScopedLeaderSharedLock

Posted by "Alexey Serbin (Code Review)" <ge...@cloudera.org>.
Alexey Serbin has submitted this change and it was merged. ( http://gerrit.cloudera.org:8080/15723 )

Change subject: [catalog_manager] reduce contention in ScopedLeaderSharedLock
......................................................................

[catalog_manager] reduce contention in ScopedLeaderSharedLock

While troubleshooting one performance issue if running a big cluster
with large number of tables and high rate of ConnectToMaster requests,
in the logs I noticed many reports like the following:

  0323 03:59:31.091198 (+607857us) spinlock_profiling.cc:243]
  Waited 492 ms on lock 0x4cb0960. stack:
    0000000002398852
    0000000000ad8c69
    0000000000aa62ba
    000000000221aaa8
    ...

which translates into
    (anonymous namespace)::SubmitSpinLockProfileData()
    master::CatalogManager::ScopedLeaderSharedLock::ScopedLeaderSharedLock()
    master::MasterServiceImpl::ConnectToMaster()
    rpc::GeneratedServiceIf::Handle()
    ...

From the code it became apparent that the lock in question was
  std::lock_guard<simple_spinlock> l(catalog_->state_lock_);
in ScopedLeaderSharedLock() constructor.

As far as I can see, there is no need to access master's Raft consensus
information (which itself might wait on its internal locks if there is
corresponding Raft-consensus activity) under the catalog's state lock.

This patch shortens the critical section with catalog's state lock held
when constructing CatalogManager::ScopedLeaderSharedLock instance.

Change-Id: I3b2e6866a8a0d5bda9e2b1f01e0668427de60868
Reviewed-on: http://gerrit.cloudera.org:8080/15698
Reviewed-by: Andrew Wong <aw...@cloudera.com>
Tested-by: Kudu Jenkins
(cherry picked from commit 14912a1fd78ba7cf4d62bf934ae64d6f6f229ee6)
Reviewed-on: http://gerrit.cloudera.org:8080/15723
Reviewed-by: Hao Hao <ha...@cloudera.com>
---
M src/kudu/master/catalog_manager.cc
1 file changed, 11 insertions(+), 7 deletions(-)

Approvals:
  Kudu Jenkins: Verified
  Hao Hao: Looks good to me, approved

-- 
To view, visit http://gerrit.cloudera.org:8080/15723
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-Project: kudu
Gerrit-Branch: branch-1.12.x
Gerrit-MessageType: merged
Gerrit-Change-Id: I3b2e6866a8a0d5bda9e2b1f01e0668427de60868
Gerrit-Change-Number: 15723
Gerrit-PatchSet: 2
Gerrit-Owner: Alexey Serbin <as...@cloudera.com>
Gerrit-Reviewer: Alexey Serbin <as...@cloudera.com>
Gerrit-Reviewer: Andrew Wong <aw...@cloudera.com>
Gerrit-Reviewer: Hao Hao <ha...@cloudera.com>
Gerrit-Reviewer: Kudu Jenkins (120)

[kudu-CR](branch-1.12.x) [catalog manager] reduce contention in ScopedLeaderSharedLock

Posted by "Hao Hao (Code Review)" <ge...@cloudera.org>.
Hao Hao has posted comments on this change. ( http://gerrit.cloudera.org:8080/15723 )

Change subject: [catalog_manager] reduce contention in ScopedLeaderSharedLock
......................................................................


Patch Set 1: Code-Review+2


-- 
To view, visit http://gerrit.cloudera.org:8080/15723
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-Project: kudu
Gerrit-Branch: branch-1.12.x
Gerrit-MessageType: comment
Gerrit-Change-Id: I3b2e6866a8a0d5bda9e2b1f01e0668427de60868
Gerrit-Change-Number: 15723
Gerrit-PatchSet: 1
Gerrit-Owner: Alexey Serbin <as...@cloudera.com>
Gerrit-Reviewer: Andrew Wong <aw...@cloudera.com>
Gerrit-Reviewer: Hao Hao <ha...@cloudera.com>
Gerrit-Reviewer: Kudu Jenkins (120)
Gerrit-Comment-Date: Tue, 14 Apr 2020 05:34:09 +0000
Gerrit-HasComments: No