Comment 3 for bug 1680316

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Deepak Rathi (rathi26) wrote : Re: [Bug 1680316] Re: Continuously high CPU utilization by PBZIP2 utility in linux system

Hi Nikolov,

Thanks for reviewing and your response.

Since pbzip2 is installed on all blade servers in the cluster but it is cpu
usage of only a specific blade i.e. sadmapp3 is going high during mentioned
backup execution duration.

Can we evenly distribute the load of subjected pbzip2 process at the time
of backup among CPU's of all cluster members instead of only using
resources of sadmapp3.

Pls guide with procedure for same if feasible wrt pbzip2 utility.

PS: CPU usage is a area of concern in my case as here the collective load
due to backup/archiving procedures + high CPU due to pbzip2, proving to be
a lethal combination and suspected to be a reason for application service
down on sadmapp3 during that time.

Thanks,
Deepak Rathi

On Apr 6, 2017 2:41 PM, "Yavor Nikolov" <email address hidden> wrote:

Why do you consider the CPU usage to be abnormal?

pbzip2 is a parallel bzip2 utility which allows to engage more of the
CPU power in compression/decompression activities (so that it runs
faster). High CPU usage is in general not something abnormal.

There is a -p flag which you may use to set the number of worker threads
to use (if not explicitly set - by default that's equal to the number of
your CPUs). As far as I see from the screenshot - there is some kind of
backup running (the tar processes) in at least 2 processes (it means
it's engaging 2 x #CPUs threads).

So you can tweak that backup - by specifying a different -p# for pbzip2,
or to run in single thread - switch to plain bzip2, or you may change
the priority of the process.

--
Maybe not related to the issue, but I also see you're using a bit old
version of pbzip2. You may find the latest release at
https://launchpad.net/pbzip2

--
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https://bugs.launchpad.net/bugs/1680316

Title:
  Continuously high CPU utilization by PBZIP2 utility in linux system

Status in pbzip2:
  New

Bug description:
  Environment:

  [root@sadmapp3 ~]# cat /etc/redhat-release
  Red Hat Enterprise Linux Server release 6.4 (Santiago)

  PBZIP2 version installed:

  [ntms@sadmapp3 ~]$ pbzip2 -V
  Parallel BZIP2 v1.1.6 - by: Jeff Gilchrist [http://compression.ca]
  [Oct. 30, 2011] (uses libbzip2 by Julian Seward)
  Major contributions: Yavor Nikolov <email address hidden>

  Issue Statement artefacts:

  Snapshot attached for reference showing abnormally high usage by
  PBSIP2 PID's.

  Hi Team,

  Please help in addressing this issue as multiple service failure
  incidents observed due to high cpu usage on a particular node, i have
  cluster setup here bu usage is high on sadmapp3 only.

  Thanks,
  Deepak Rathi

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