Hi,

Thanks for answering me!

It is happy to hear the problem will be addressed. :)

About question 2, flink-runtime uses Apache Httpclient 4.2.6 and S3 file system 
api implemented by Amazon uses 4.3.x. There are some API changes, so 
NoSuchMethodError exception occurs.

> On Jan 5, 2016, at 11:59 PM, Stephan Ewen <se...@apache.org> wrote:
> 
> Hi!
> 
> Concerning (1) We have seen that a few times. The JVMs / Threads do sometimes 
> not properly exit in a graceful way, and YARN is not always able to kill the 
> process (YARN bug). I am currently working on a refactoring of the YARN 
> resource manager (to allow to easy addition of other frameworks) and have 
> addressed this as part of that. Will be in the master in a bit.
> 
> Concerning (2) Do you know which component in Flink uses the HTTP client?
> 
> Greetings,
> Stephan
> 
> 
> On Tue, Jan 5, 2016 at 2:49 PM, Maximilian Bode <maximilian.b...@tngtech.com> 
> wrote:
> Hi everyone,
> 
> Regarding Q1, I believe I have witnessed a comparable phenomenon in a 
> (3-node, non-EMR) YARN cluster. After shutting down the yarn session via 
> `stop`, one container seems to linger around. `yarn application -list` is 
> empty, whereas `bin/yarn-session.sh -q` lists the left-over container. Also, 
> there is still one application shown as ‚running‘ in Ambari’s YARN pane under 
> current applications. Then, after some time (order of a few minutes) it 
> disappears and the resources are available again.
> 
> I have not tested this behavior extensibly so far. Noticeably, I was not able 
> to reproduce it by just starting a session and then ending it again right 
> away without looking at the JobManager web interface. Maybe this produces 
> some kind of lag as far as YARN containers are concerned?
> 
> Cheers,
> Max
> 
> > Am 04.01.2016 um 12:52 schrieb Chiwan Park <chiwanp...@apache.org>:
> >
> > Hi All,
> >
> > I have some problems using Flink on Amazon EMR cluster.
> >
> > Q1. Sometimes, jobmanager container still exists after destroying yarn 
> > session by pressing Ctrl+C. In that case, Flink YARN app seems exited 
> > correctly in YARN RM dashboard. But there is a running container in the 
> > dashboard. From logs of the container, I realize that the container is 
> > jobmanager.
> >
> > I cannot kill the container because there is no permission to restart YARN 
> > RM in Amazon EMR. In my small Hadoop Cluster (w/3 nodes), the problem 
> > doesn’t appear.
> >
> > Q2. I tried to use S3 file system in Flink on EMR. But I can’t use it 
> > because of version conflict of Apache Httpclient. In default, 
> > implementation of S3 file system in EMR is 
> > `com.amazon.ws.emr.hadoop.fs.s3n.S3NativeFileSystem` which is linked with 
> > other version of Apache Httpclient.
> >
> > As I wrote above, I cannot restart Hadoop cluster after modifying 
> > conf-site.xml because of lack of permission. How can I solve this problem?
> >
> > Regards,
> > Chiwan Park
> >
> >

Regards,
Chiwan Park


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