[Gluster-devel] [Gluster-users] GlusterFS (3.3.1) - performance issues - large number of LOOKUP calls & high CPU usage
Song
gluster at 163.com
Mon Jun 24 01:10:28 UTC 2013
My kernel version is 2.6.32-220.23.1.el6.x86_64
OS: CentOS 6.2
-----Original Message-----
From: Stephan von Krawczynski [mailto:skraw at ithnet.com]
Sent: Friday, June 21, 2013 2:30 PM
To: Song
Cc: 'Pablo'; gluster-devel at nongnu.org
Subject: Re: [Gluster-devel] [Gluster-users] GlusterFS (3.3.1) - performance issues - large number of LOOKUP calls & high CPU usage
What kind of kernel are you using? Your googled article turns round kernel versions 2.6.something.
I really do wonder if the same effects show up on recent 3.9.(7) ...
On Fri, 21 Jun 2013 11:53:41 +0800
"Song" <gluster at 163.com> wrote:
> I use perf top and try to see where in the kernel code all this time
> was being spend. Following is what I was seeing:
>
>
>
> PerfTop: 2036 irqs/sec kernel:100.0% exact: 0.0% [1000Hz cycles],
> (target_pid: 5336)
>
> ----------------------------------------------------------------------
> ------
> ------------------------------
>
>
>
> samples pcnt function DSO
>
> _______ _____ _________________________ _________________
>
>
>
> 11265.00 91.0% _spin_lock_irq [kernel.kallsyms]
>
> 355.00 2.9% _spin_lock_irqsave [kernel.kallsyms]
>
> 249.00 2.0% compaction_alloc [kernel.kallsyms]
>
> 235.00 1.9% compact_zone [kernel.kallsyms]
>
> 151.00 1.2% get_pageblock_flags_group [kernel.kallsyms]
>
> 32.00 0.3% _cond_resched [kernel.kallsyms]
>
> 27.00 0.2% copy_page_c [kernel.kallsyms]
>
> 8.00 0.1% _spin_lock [kernel.kallsyms]
>
> 6.00 0.0% mem_cgroup_del_lru_list [kernel.kallsyms]
>
> 5.00 0.0% __wake_up_bit [kernel.kallsyms]
>
>
>
> Then, I use “perf record -g -p 5336” to capture the percent of kernel
> call and find “compact_zone” is very busy.
>
>
>
> [root at bj-nx-cip-w87 ~]# perf report --stdio
>
> # Events: 47K cycles
>
> #
>
> # Overhead Command Shared Object
> Symbol
>
> # ........ ......... .....................
> ......................................
>
> #
>
> 91.51% glusterfs [kernel.kallsyms] [k] _spin_lock_irq
>
> |
>
> --- _spin_lock_irq
>
> |
>
> |--99.64%-- compact_zone
>
> | compact_zone_order
>
> | try_to_compact_pages
>
> | __alloc_pages_nodemask
>
> | alloc_pages_vma
>
> | do_huge_pmd_anonymous_page
>
> | handle_mm_fault
>
> | __do_page_fault
>
> | do_page_fault
>
> | page_fault
>
> | |
>
> | |--94.45%-- xdr_callmsg_internal
>
> | | 0x3829b98860
>
> | |
>
> | --5.55%-- __memcpy_sse2
>
> --0.36%-- [...]
>
>
>
> Last, I google “compact_zone” and find the article “Linux 6
> Transparent Huge Pages and Hadoop Workloads
> <http://structureddata.org/2012/06/18/linux-6-transparent-huge-pages-a
> nd-had oop-workloads/> ”. The sample issues is occurred in hadoop.
>
> THP can be disabled by running the following command:
>
> echo never > /sys/kernel/mm/redhat_transparent_hugepage/enabled
>
>
>
> CPU usage and work load is normal.
>
>
>
> From: gluster-devel-bounces+gluster=163.com at nongnu.org
> [mailto:gluster-devel-bounces+gluster=163.com at nongnu.org] On Behalf Of
> Song
> Sent: Friday, June 07, 2013 1:34 PM
> To: 'Stephan von Krawczynski'; 'Pablo'
> Cc: gluster-devel at nongnu.org
> Subject: Re: [Gluster-devel] [Gluster-users] GlusterFS (3.3.1) -
> performance issues - large number of LOOKUP calls & high CPU usage
>
>
>
> We have met same performance issues when open a file. Sometime, it
> cost more than 10 seconds that a file open.
>
>
>
> We add some debug info to locate this problem and test again and
> again, find it's will cost a few seconds when execute 'xdr_callmsg'
> function in 'rpc_request_to_xdr'.
>
>
>
> A typical example of log is as below. From [2013-06-06
> 13:34:59.471004] to
> [2013-06-06 13:35:04.890363] , 'xdr_callmsg' function cost more than 5
> seconds.
>
>
>
> [2013-06-06 13:34:59.470991] I
> [rpc-clnt.c:1175:rpc_clnt_record_build_record] 0-gfs1-client-51:
> (thread_id is 140257410492160 )add for open_slow rpc_fill_request_end
>
> [2013-06-06 13:34:59.471004] I [xdr-rpcclnt.c:87:rpc_request_to_xdr] 0-rpc:
> (thread_id is 140257410492160 len = 131072 )add for open_slow
> xdrmem_create_end
>
> [2013-06-06 13:34:59.570044] I [client.c:124:client_submit_request]
> 0-gfs1-client-86: (thread_id is 140257819739904 )add for open_slow
> rpc_clnt_submit
>
> [2013-06-06 13:34:59.570091] I [rpc-clnt.c:1363:rpc_clnt_submit]
> 0-gfs1-client-86: (thread_id is 140257819739904 )add for open_slow
> callid end
>
>
>
> ......
>
>
>
> [2013-06-06 13:34:59.579865] I
> [client3_1-fops.c:2235:client3_1_lookup_cbk]
> 0-gfs1-client-5: (thread_id is 140257819739904)add for open_slow
> lookup_cbk
> path=/xmail_dedup/gfs1_000/1FA/1B1
>
> [2013-06-06 13:34:59.579917] I
> [client3_1-fops.c:2235:client3_1_lookup_cbk]
> 0-gfs1-client-6: (thread_id is 140257819739904)add for open_slow
> lookup_cbk
> path=/xmail_dedup/gfs1_000/1FA/1B1
>
> [2013-06-06 13:35:04.890363] I [xdr-rpcclnt.c:92:rpc_request_to_xdr] 0-rpc:
> (thread_id is 140257410492160 )add for open_slow xdr_callmsg_end
>
> [2013-06-06 13:35:04.890366] I [client.c:110:client_submit_request]
> 0-gfs1-client-44: (thread_id is 140257785079552 )add for open_slow
> create the xdr payload
>
>
>
>
>
> Native client and use 5 glusterfs in one server. When performance
> issues appear, the cpu usage is as below:
>
>
>
> top - 13:45:37 up 57 days, 14:04, 4 users, load average: 6.98, 5.38,
> 4.67
>
> Tasks: 712 total, 8 running, 704 sleeping, 0 stopped, 0 zombie
>
> Cpu(s): 3.2%us, 63.5%sy, 0.0%ni, 31.5%id, 1.4%wa, 0.0%hi, 0.4%si,
> 0.0%st
>
> Mem: 65956748k total, 55218008k used, 10738740k free, 3362972k
> buffers
>
> Swap: 8388600k total, 41448k used, 8347152k free, 37370840k cached
>
>
>
> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
>
> 13905 root 20 0 554m 363m 2172 R 244.8 0.6 9:51.01 glusterfs
>
> 13650 root 20 0 766m 610m 2056 R 184.8 0.9 18:24.37 glusterfs
>
> 13898 root 20 0 545m 356m 2176 R 179.2 0.6 12:04.87 glusterfs
>
> 13919 root 20 0 547m 360m 2172 R 111.6 0.6 9:16.89 glusterfs
>
> 22460 root 20 0 486m 296m 2200 S 100.4 0.5 194:59.10 glusterfs
>
> 13878 root 20 0 545m 361m 2176 R 99.7 0.6 8:35.88 glusterfs
>
>
>
>
>
> -----Original Message-----
> From: gluster-users-bounces at gluster.org
> [mailto:gluster-users-bounces at gluster.org] On Behalf Of Stephan von
> Krawczynski
> Sent: Thursday, June 06, 2013 10:07 PM
> To: Pablo
> Cc: gluster-users at gluster.org
> Subject: Re: [Gluster-users] GlusterFS (3.3.1) - performance issues -
> large number of LOOKUP calls & high CPU usage
>
>
>
> On Thu, 06 Jun 2013 10:39:21 -0300
>
> Pablo < <mailto:paa.listas at gmail.com> paa.listas at gmail.com> wrote:
>
>
>
> > I have never try this (In fact I'm just learning a bit more how to
>
> > administer a Gluster server.), buy you may find it useful.
>
> >
>
> >
> <http://download.gluster.org/pub/gluster/glusterfs/doc/HA%20and%20Load
> %25>
> http://download.gluster.org/pub/gluster/glusterfs/doc/HA%20and%20Load%
>
> > 20Balancing%20for%20NFS%20and%20SMB.html
>
> >
>
> > Pablo.
>
>
>
> The thing with this way of failover is though, that you will likely
> corrupt a currently written file. If your NFS-server (gluster) node
> dies while you write your file will be corrupt. If you use native
> glusterfs mounts it will not (should not). This is why I consider the
> NFS server feature nothing more than a bad hack. It does not deliver
> the safety that glusterfs promises, even if you solve the failover problem somehow.
>
>
>
> --
>
> Regards,
>
> Stephan
>
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