Repository: samza Updated Branches: refs/heads/master d05f9ca38 -> a56a77769
SAMZA-886 - Investigate 'relax locality' to improve Host Affinity Project: http://git-wip-us.apache.org/repos/asf/samza/repo Commit: http://git-wip-us.apache.org/repos/asf/samza/commit/a56a7776 Tree: http://git-wip-us.apache.org/repos/asf/samza/tree/a56a7776 Diff: http://git-wip-us.apache.org/repos/asf/samza/diff/a56a7776 Branch: refs/heads/master Commit: a56a777699bce706dbf7c5086fea8c87e72507aa Parents: d05f9ca Author: Jacob Maes <jacob.m...@gmail.com> Authored: Wed Apr 20 10:30:39 2016 -0700 Committer: Navina Ramesh <nram...@linkedin.com> Committed: Wed Apr 20 10:30:39 2016 -0700 ---------------------------------------------------------------------- docs/learn/documentation/versioned/yarn/yarn-host-affinity.md | 1 + 1 file changed, 1 insertion(+) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/samza/blob/a56a7776/docs/learn/documentation/versioned/yarn/yarn-host-affinity.md ---------------------------------------------------------------------- diff --git a/docs/learn/documentation/versioned/yarn/yarn-host-affinity.md b/docs/learn/documentation/versioned/yarn/yarn-host-affinity.md index 986236a..12645fa 100644 --- a/docs/learn/documentation/versioned/yarn/yarn-host-affinity.md +++ b/docs/learn/documentation/versioned/yarn/yarn-host-affinity.md @@ -102,6 +102,7 @@ export LOGGED_STORE_BASE_DIR=<path-for-state-stores> <value>600000</value> <!-- Set it to 10min to allow enough time for clean shutdown of containers --> </property> {% endhighlight %} +4. The Yarn [Rack Awareness](https://hadoop.apache.org/docs/stable/hadoop-project-dist/hadoop-common/RackAwareness.html) feature is not required and does not change the behavior of Samza Host Affinity. However, if Rack Awareness is configured in the cluster, make sure the DNSToSwitchMapping implementation is robust. Any failures could cause container requests to fall back to the defaultRack. This will cause ContainerRequests to not match the preferred host, which will degrade Host Affinity. For details, see [SAMZA-866](https://issues.apache.org/jira/browse/SAMZA-886) ## Configuring a Samza job to use Host Affinity Any stateful Samza job can leverage this feature to reduce the Mean Time To Restore (MTTR) of it's state stores by setting <code>yarn.samza.host-affinity</code> to true.
