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Posted to commits@mesos.apache.org by bm...@apache.org on 2018/07/17 00:41:39 UTC

[1/2] mesos git commit: Improved performance of cgroups::read by verifying after failure.

Repository: mesos
Updated Branches:
  refs/heads/1.4.x 5f6d4cdc7 -> 163dd77ef


Improved performance of cgroups::read by verifying after failure.

It turns out that cgroups::verify is expensive and leads to a severe
performance issue on the agent during container metrics collection
if there are a lot of containers on the agent. See MESOS-8418.

Since cgroups::verify serves to provide a helpful error message,
this patch preserves the error message, but only if the read fails.

Longer term, there probably needs to be some re-structuring of the
code to make verification caller-controlled, or perhaps the verify
code can occur consistently post-operation (as done in this patch),
or perhaps verify can be optimized substantially.

Review: https://reviews.apache.org/r/67923/


Project: http://git-wip-us.apache.org/repos/asf/mesos/repo
Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/4fc17599
Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/4fc17599
Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/4fc17599

Branch: refs/heads/1.4.x
Commit: 4fc1759965b8a4ae00f70a05406a3b93e52150dc
Parents: 5f6d4cd
Author: Benjamin Mahler <bm...@apache.org>
Authored: Mon Jul 16 17:22:45 2018 -0700
Committer: Benjamin Mahler <bm...@apache.org>
Committed: Mon Jul 16 17:36:08 2018 -0700

----------------------------------------------------------------------
 src/linux/cgroups.cpp | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/mesos/blob/4fc17599/src/linux/cgroups.cpp
----------------------------------------------------------------------
diff --git a/src/linux/cgroups.cpp b/src/linux/cgroups.cpp
index 0a7bb89..ab594e0 100644
--- a/src/linux/cgroups.cpp
+++ b/src/linux/cgroups.cpp
@@ -946,12 +946,25 @@ Try<string> read(
     const string& cgroup,
     const string& control)
 {
-  Option<Error> error = verify(hierarchy, cgroup, control);
-  if (error.isSome()) {
-    return error.get();
+  Try<string> read = internal::read(hierarchy, cgroup, control);
+
+  // It turns out that `verify()` is expensive, so rather than
+  // verifying *prior* to the read, as is currently done for other
+  // cgroup helpers, we only verify if the read fails. This ensures
+  // we still provide a good error message. See: MESOS-8418.
+  //
+  // TODO(bmahler): Longer term, verification should be done
+  // explicitly by the caller, or its performance should be
+  // improved, or verification could be done consistently
+  // post-failure, as done here.
+  if (read.isError()) {
+    Option<Error> error = verify(hierarchy, cgroup, control);
+    if (error.isSome()) {
+      return error.get();
+    }
   }
 
-  return internal::read(hierarchy, cgroup, control);
+  return read;
 }
 
 


[2/2] mesos git commit: Add MESOS-8418 to the 1.4.2 CHANGELOG.

Posted by bm...@apache.org.
Add MESOS-8418 to the 1.4.2 CHANGELOG.


Project: http://git-wip-us.apache.org/repos/asf/mesos/repo
Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/163dd77e
Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/163dd77e
Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/163dd77e

Branch: refs/heads/1.4.x
Commit: 163dd77ef8702fce4d6bcadfbcee2f2aeeb0c5f5
Parents: 4fc1759
Author: Benjamin Mahler <bm...@apache.org>
Authored: Mon Jul 16 17:40:27 2018 -0700
Committer: Benjamin Mahler <bm...@apache.org>
Committed: Mon Jul 16 17:40:45 2018 -0700

----------------------------------------------------------------------
 CHANGELOG | 1 +
 1 file changed, 1 insertion(+)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/mesos/blob/163dd77e/CHANGELOG
----------------------------------------------------------------------
diff --git a/CHANGELOG b/CHANGELOG
index 22872ad..4396f39 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -18,6 +18,7 @@ Release Notes - Mesos - Version 1.4.2 (WIP)
   * [MESOS-8352] - Resources may get over allocated to some roles while fail to meet the quota of other roles.
   * [MESOS-8356] - Persistent volume ownership is set to root despite of sandbox owner (frameworkInfo.user) when docker executor is used.
   * [MESOS-8411] - Killing a queued task can lead to the command executor never terminating.
+  * [MESOS-8418] - mesos-agent high cpu usage because of numerous /proc/mounts reads.
   * [MESOS-8480] - Mesos returns high resource usage when killing a Docker task.
   * [MESOS-8488] - Docker bug can cause unkillable tasks.
   * [MESOS-8550] - Bug in `Master::detected()` leads to coredump in `MasterZooKeeperTest.MasterInfoAddress`.