[Gluster-users] Gluter 3.12.12: performance during heal and in general

[Hu Bert]

gluster volume heal shared info | grep -i number
Number of entries: 0
Number of entries: 0
Number of entries: 0
Number of entries: 0
Number of entries: 0
Number of entries: 0
Number of entries: 0
Number of entries: 0
Number of entries: 0
Number of entries: 0
Number of entries: 0
Number of entries: 0

Looks good to me.


2018-08-20 10:51 GMT+02:00 Pranith Kumar Karampuri <pkarampu at redhat.com>:
> There are a lot of Lookup operations in the system. But I am not able to
> find why. Could you check the output of
>
> # gluster volume heal <volname> info | grep -i number
>
> it should print all zeros.
>
> On Fri, Aug 17, 2018 at 1:49 PM Hu Bert <revirii at googlemail.com> wrote:
>>
>> I don't know what you exactly mean with workload, but the main
>> function of the volume is storing (incl. writing, reading) images
>> (from hundreds of bytes up to 30 MBs, overall ~7TB). The work is done
>> by apache tomcat servers writing to / reading from the volume. Besides
>> images there are some text files and binaries that are stored on the
>> volume and get updated regularly (every x hours); we'll try to migrate
>> the latter ones to local storage asap.
>>
>> Interestingly it's only one process (and its threads) of the same
>> brick on 2 of the gluster servers that consumes the CPU.
>>
>> gluster11: bricksdd1; not healed; full CPU
>> gluster12: bricksdd1; got healed; normal CPU
>> gluster13: bricksdd1; got healed; full CPU
>>
>> Besides: performance during heal (e.g. gluster12, bricksdd1) was way
>> better than it is now. I've attached 2 pngs showing the differing cpu
>> usage of last week before/after heal.
>>
>> 2018-08-17 9:30 GMT+02:00 Pranith Kumar Karampuri <pkarampu at redhat.com>:
>> > There seems to be too many lookup operations compared to any other
>> > operations. What is the workload on the volume?
>> >
>> > On Fri, Aug 17, 2018 at 12:47 PM Hu Bert <revirii at googlemail.com> wrote:
>> >>
>> >> i hope i did get it right.
>> >>
>> >> gluster volume profile shared start
>> >> wait 10 minutes
>> >> gluster volume profile shared info
>> >> gluster volume profile shared stop
>> >>
>> >> If that's ok, i've attached the output of the info command.
>> >>
>> >>
>> >> 2018-08-17 8:31 GMT+02:00 Pranith Kumar Karampuri
>> >> <pkarampu at redhat.com>:
>> >> > Please do volume profile also for around 10 minutes when CPU% is
>> >> > high.
>> >> >
>> >> > On Fri, Aug 17, 2018 at 11:56 AM Pranith Kumar Karampuri
>> >> > <pkarampu at redhat.com> wrote:
>> >> >>
>> >> >> As per the output, all io-threads are using a lot of CPU. It is
>> >> >> better
>> >> >> to
>> >> >> check what the volume profile is to see what is leading to so much
>> >> >> work
>> >> >> for
>> >> >> io-threads. Please follow the documentation at
>> >> >>
>> >> >>
>> >> >> https://gluster.readthedocs.io/en/latest/Administrator%20Guide/Monitoring%20Workload/
>> >> >> section: "
>> >> >>
>> >> >> Running GlusterFS Volume Profile Command"
>> >> >>
>> >> >> and attach output of  "gluster volume profile info",
>> >> >>
>> >> >> On Fri, Aug 17, 2018 at 11:24 AM Hu Bert <revirii at googlemail.com>
>> >> >> wrote:
>> >> >>>
>> >> >>> Good morning,
>> >> >>>
>> >> >>> i ran the command during 100% CPU usage and attached the file.
>> >> >>> Hopefully it helps.
>> >> >>>
>> >> >>> 2018-08-17 7:33 GMT+02:00 Pranith Kumar Karampuri
>> >> >>> <pkarampu at redhat.com>:
>> >> >>> > Could you do the following on one of the nodes where you are
>> >> >>> > observing
>> >> >>> > high
>> >> >>> > CPU usage and attach that file to this thread? We can find what
>> >> >>> > threads/processes are leading to high usage. Do this for say 10
>> >> >>> > minutes
>> >> >>> > when
>> >> >>> > you see the ~100% CPU.
>> >> >>> >
>> >> >>> > top -bHd 5 > /tmp/top.${HOSTNAME}.txt
>> >> >>> >
>> >> >>> > On Wed, Aug 15, 2018 at 2:37 PM Hu Bert <revirii at googlemail.com>
>> >> >>> > wrote:
>> >> >>> >>
>> >> >>> >> Hello again :-)
>> >> >>> >>
>> >> >>> >> The self heal must have finished as there are no log entries in
>> >> >>> >> glustershd.log files anymore. According to munin disk latency
>> >> >>> >> (average
>> >> >>> >> io wait) has gone down to 100 ms, and disk utilization has gone
>> >> >>> >> down
>> >> >>> >> to ~60% - both on all servers and hard disks.
>> >> >>> >>
>> >> >>> >> But now system load on 2 servers (which were in the good state)
>> >> >>> >> fluctuates between 60 and 100; the server with the formerly
>> >> >>> >> failed
>> >> >>> >> disk has a load of 20-30.I've uploaded some munin graphics of
>> >> >>> >> the
>> >> >>> >> cpu
>> >> >>> >> usage:
>> >> >>> >>
>> >> >>> >> https://abload.de/img/gluster11_cpu31d3a.png
>> >> >>> >> https://abload.de/img/gluster12_cpu8sem7.png
>> >> >>> >> https://abload.de/img/gluster13_cpud7eni.png
>> >> >>> >>
>> >> >>> >> This can't be normal. 2 of the servers under heavy load and one
>> >> >>> >> not
>> >> >>> >> that much. Does anyone have an explanation of this strange
>> >> >>> >> behaviour?
>> >> >>> >>
>> >> >>> >>
>> >> >>> >> Thx :-)
>> >> >>> >>
>> >> >>> >> 2018-08-14 9:37 GMT+02:00 Hu Bert <revirii at googlemail.com>:
>> >> >>> >> > Hi there,
>> >> >>> >> >
>> >> >>> >> > well, it seems the heal has finally finished. Couldn't
>> >> >>> >> > see/find
>> >> >>> >> > any
>> >> >>> >> > related log message; is there such a message in a specific log
>> >> >>> >> > file?
>> >> >>> >> >
>> >> >>> >> > But i see the same behaviour when the last heal finished: all
>> >> >>> >> > CPU
>> >> >>> >> > cores are consumed by brick processes; not only by the
>> >> >>> >> > formerly
>> >> >>> >> > failed
>> >> >>> >> > bricksdd1, but by all 4 brick processes (and their threads).
>> >> >>> >> > Load
>> >> >>> >> > goes
>> >> >>> >> > up to > 100 on the 2 servers with the not-failed brick, and
>> >> >>> >> > glustershd.log gets filled with a lot of entries. Load on the
>> >> >>> >> > server
>> >> >>> >> > with the then failed brick not that high, but still ~60.
>> >> >>> >> >
>> >> >>> >> > Is this behaviour normal? Is there some post-heal after a heal
>> >> >>> >> > has
>> >> >>> >> > finished?
>> >> >>> >> >
>> >> >>> >> > thx in advance :-)
>> >> >>> >
>> >> >>> >
>> >> >>> >
>> >> >>> > --
>> >> >>> > Pranith
>> >> >>
>> >> >>
>> >> >>
>> >> >> --
>> >> >> Pranith
>> >> >
>> >> >
>> >> >
>> >> > --
>> >> > Pranith
>> >
>> >
>> >
>> > --
>> > Pranith
>
>
>
> --
> Pranith