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https://issues.apache.org/jira/browse/YARN-3192?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14320771#comment-14320771
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Steve Loughran commented on YARN-3192:
--------------------------------------
Thank you. I believe I understand precisely why swallowing interrupted
exceptions matter. In fact, I will refer you to HADOOP-6221, which fixed it
somewhere used across the codebase (RPCClient) and included a test in the fix,
so we can even replicate a problem which was stopping me shutting down my
client cleanly on a ^C signal, which is why [my app's entry
point|https://github.com/apache/incubator-slider/blob/develop/slider-core/src/main/java/org/apache/slider/core/main/ServiceLauncher.java#L252]
starts an async shutdown timer as well as recognising a double ^C signal as a
sign to escalate to a JVM halt.
What I am saying is: this is not a place where it matters.
Look at the one place the {{join()}} method is called
[WebAppProxyServer.main()|https://github.com/apache/hadoop/blob/trunk/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/src/main/java/org/apache/hadoop/yarn/server/webproxy/WebAppProxyServer.java#L93]]
it's caught and translated, as Chris points out, into a "this is the shutdown
you asked for", which then exits with a 0.
Signalling a clean shutdown is the desired action here, not exiting with a -1.
Note also our use of the sole exit mechanism we allow in the Hadoop codebase,
via a call to {{ExitUtil.terminate(-1, t);}}. That's new to branch-2+ as of
this week; until then the code was "errant".
if you're going to touch {{join()}}, rather than have it throw, have it exit
with a boolean to indicate "managed shutdown vs interruption". It'll be ignored
either way, but if it makes you confident the code is better, then I wont say
known.
> Empty handler for exception: java.lang.InterruptedException #WebAppProxy.java
> and #/ResourceManager.java
> --------------------------------------------------------------------------------------------------------
>
> Key: YARN-3192
> URL: https://issues.apache.org/jira/browse/YARN-3192
> Project: Hadoop YARN
> Issue Type: Bug
> Affects Versions: 2.6.0
> Reporter: Brahma Reddy Battula
> Assignee: Brahma Reddy Battula
> Attachments: YARN-3192.patch
>
>
> The InterruptedException is completely ignored. As a result, any events
> causing this interrupt will be lost.
> File: org/apache/hadoop/yarn/server/resourcemanager/ResourceManager.java
> {code}
> try {
> event = eventQueue.take();
> } catch (InterruptedException e) {
> LOG.error("Returning, interrupted : " + e);
> return; // TODO: Kill RM.
> }
> {code}
> File: "org/apache/hadoop/yarn/server/webproxy/WebAppProxy.java"
> {code}
> public void join() {
> if(proxyServer != null) {
> try {
> proxyServer.join();
> } catch (InterruptedException e) {
> }
> }
> }
> {code}
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