Steve Suh created YARN-10857:
--------------------------------
Summary: YarnClient Caching Addresses
Key: YARN-10857
URL: https://issues.apache.org/jira/browse/YARN-10857
Project: Hadoop YARN
Issue Type: Improvement
Components: client, yarn
Reporter: Steve Suh
We have noticed that when the YarnClient is initialized and used, it is not
very resilient when dns or /etc/hosts is modified in the following scenario:
Take for instance the following (and reproducable) sequence of events that can
occur on a service that instantiates and uses YarnClient.
- Yarn has rm HA enabled (`yarn.resourcemanager.ha.enabled` is `true`) and
there are two rms (rm1 and rm2).
- `yarn.client.failover-proxy-provider` is set to
`org.apache.hadoop.yarn.client.RequestHedgingRMFailoverProxyProvider`
1) rm2 is currently the active rm
2) /etc/hosts (or dns) is missing host information for rm2
3) A service is started and it initializes the YarnClient at startup.
4) At some point in time after YarnClient is done initializing, /etc/hosts
is updated and contains host information for rm2
5) Yarn is queried using YarnClient, for instance calling
`.getApplications()`
6) All YarnClient attempts to communicate with rm2 fail with
UnknownHostExceptions, even though /etc/hosts now contains host information for
it.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
