mesos git commit: Changed default htb leaf qdisc to fq_codel in port mapping isolator.

[ji...@apache.org]

Repository: mesos
Updated Branches:
  refs/heads/master a12242bd6 -> d82ec9207


Changed default htb leaf qdisc to fq_codel in port mapping isolator.

Review: https://reviews.apache.org/r/32219


Project: http://git-wip-us.apache.org/repos/asf/mesos/repo
Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/d82ec920
Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/d82ec920
Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/d82ec920

Branch: refs/heads/master
Commit: d82ec92073b0438589e7aa72e608c3dc334a8dd6
Parents: a12242b
Author: Cong Wang <cw...@twopensource.com>
Authored: Mon Mar 23 11:33:09 2015 -0700
Committer: Jie Yu <yu...@gmail.com>
Committed: Mon Mar 23 11:36:11 2015 -0700

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 src/slave/containerizer/isolators/network/port_mapping.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)
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http://git-wip-us.apache.org/repos/asf/mesos/blob/d82ec920/src/slave/containerizer/isolators/network/port_mapping.cpp
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diff --git a/src/slave/containerizer/isolators/network/port_mapping.cpp b/src/slave/containerizer/isolators/network/port_mapping.cpp
index 7b4aac8..f1f4007 100644
--- a/src/slave/containerizer/isolators/network/port_mapping.cpp
+++ b/src/slave/containerizer/isolators/network/port_mapping.cpp
@@ -2860,6 +2860,14 @@ string PortMappingIsolatorProcess::scripts(Info* info)
     script << "tc class add dev " << eth0 << " parent 1: classid 1:1 htb rate "
            << egressRateLimitPerContainer.get().bytes() * 8 << "bit\n";
 
+    // Packets are buffered at the leaf qdisc if we send them faster
+    // than the HTB rate limit and may be dropped when the queue is
+    // full, so we change the default leaf qdisc from pfifo_fast to
+    // fq_codel, which has a larger buffer and better control on
+    // buffer bloat.
+    // TODO(cwang): Verity that fq_codel qdisc is available.
+    script << "tc qdisc add dev " << eth0 << " parent 1:1 fq_codel\n";
+
     // Display the htb qdisc and class created on eth0.
     script << "tc qdisc show dev " << eth0 << "\n";
     script << "tc class show dev " << eth0 << "\n";