Hi Naga,
Thanks much. This can explain why I am seeing the behavior. Application
Manager is using 1.5GB of memory on the idle machine which leaves no space
for other containers to run on that machine.
To answer your other questions:
* Memory configuration of AM container
yarn.app.mapreduce.am.command-opts: Xmx1024m
yarn.app.mapreduce.am.resource.mb: 1536
* Containers which are running in the idling machine, is it always the same
> machine or different everytime. are there any other processes running in
> that machine if always same
It changes across runs, but I am tearing down and setting up the Hadoop
cluster every time. Only hadoop processes and a collector are running on
the machines. The collector has a memory footprint of around 10~ MBs and
uses less than 0.2 percent of the CPU time.
* Job counters for both the runs will also provide useful information
> please share across.
Unfortunately, I had no luck setting up the job history daemon. After
issuing: mapred job -history [JobHistoryId] I get an error that the history
file does not exist -- it's a FileIOException on a path in the form of:
/user/{hadoop.user}/job.id.
I tried setting up these variables but they don't seem to have any effects.
yarn.log-aggregation-enable
mapreduce.jobtracker.jobhistory.location
mapreduce.jobtracker.jobhistory.completed.location
I also ran the history server through: mr-jobhistory-daemon.sh start
historyserver
Thanks,
Omid
On Mon, Aug 24, 2015 at 11:09 PM, Naganarasimha G R (Naga) <
[email protected]> wrote:
> Hi Omid,
> Seems like the machine which was running slow might have the AM container
> also and possibly 2GB is assigned to it.
> Can you share the following details :
> * Memory configuration of AM container
> * Containers which are running in the idling machine, is it always the
> same machine or different everytime. are there any other processes running
> in that machine if always same
> * Job counters for both the runs will also provide useful information
> please share across.
>
> Regards,
> + Naga
>
>
> ------------------------------
> *From:* Omid Alipourfard [[email protected]]
> *Sent:* Tuesday, August 25, 2015 07:23
> *To:* [email protected]
> *Subject:* Questions with regards to Yarn/Hadoop
>
> Hi,
>
> I am running a Terasort benchmark (10 GB, 25 reducers, 50 mappers) that
> comes with Hadoop 2.7.1. I am experiencing an unexpected behavior with
> Yarn, which I am hoping someone can shed some light on:
>
> I have a cluster of three machines with 2 cores and 3.75 GB of RAM (per
> machine), when I run the Terasort job, one of the machines is idling, i.e.,
> it is not using any substantial Disk or CPU. All three machines are
> capable of executing jobs, and one of the machines is both a name node and
> a data node.
>
> On the other hand, running the same job on a cluster of three machines
> with 2 cores and 8 GB of RAM (per machine) utilizes all the machines.
>
> Both setups are using the same Hadoop configuration files, in both of them
> mapper tasks have 1 GB and reducer tasks have 2 GB of memory.
>
> I am guessing Yarn is not utilizing the machines correctly -- maybe
> because of the available amount of RAM, but I am not sure how to verify
> this.
>
> Any thoughts on what the problem might be or how to verify it is
> appreciated,
> Thanks,
> Omid
>
> P.S. I can also post any of the logs or configuration files.
>
