[Gluster-users] High CPU/load, High latency on FSYNC

Serkan Çoban cobanserkan at gmail.com
Fri Mar 31 08:07:38 UTC 2017


Prometheus uses *LOTS* of small files and do small random-io.
I do not recommend to use data volume of prometheus on glusterfs.
Why you need that?


On Fri, Mar 31, 2017 at 10:30 AM, Yong Zhang <hiscal at outlook.com> wrote:

> Hi, All
>
>
>
> I have glusterfs 3.10.0 running with two replicated nodes, but one of the
> node has a bad CPU performance:
>
>
>
> Node1/Node2: 4 core, 8GB, using thin LVM for volumes
>
>
>
> This is node1:
>
>
>
> And this is node2:
>
>
>
> Currently I have only Prometheus using glusterfs volumes, so I started
> profile on volume prometheus and got this:
>
>
>
> Brick: 10.10.0.100:/glusterfsvolumes/devops/devops-prometheus/brick
>
> -------------------------------------------------------------------
>
> Cumulative Stats:
>
>    Block Size:                  2b+
> 4b+                   8b+
>
>  No. of Reads:                    0
> 0                     0
>
> No. of Writes:                    1
> 1                    31
>
>
>
>    Block Size:                 16b+                  32b+
> 64b+
>
>  No. of Reads:                    0
> 1                     0
>
> No. of Writes:                   20                  4283
> 3085
>
>
>
>    Block Size:                128b+                 256b+
> 512b+
>
>  No. of Reads:                    0
> 1                     0
>
> No. of Writes:                  395
> 465                   555
>
>
>
>    Block Size:               1024b+                2048b+
> 4096b+
>
>  No. of Reads:                    4
> 6                    32
>
> No. of Writes:                72453                 62462
> 52882
>
>
>
>    Block Size:               8192b+               16384b+
> 32768b+
>
>  No. of Reads:                  154
> 281                   484
>
> No. of Writes:                43122                 21700
> 17817
>
>
>
>    Block Size:              65536b+              131072b+
>
>  No. of Reads:                  993                 15290
>
> No. of Writes:                56237                581071
>
>  %-latency   Avg-latency   Min-Latency   Max-Latency   No. of
> calls         Fop
>
> ---------   -----------   -----------   -----------   ------------
> ----
>
>       0.00       0.00 us       0.00 us       0.00 us         205094
> FORGET
>
>       0.00       0.00 us       0.00 us       0.00 us         245895
> RELEASE
>
>       0.00       0.00 us       0.00 us       0.00 us          40492
> RELEASEDIR
>
>       0.00      20.50 us      19.00 us      22.00 us              2
> FSYNCDIR
>
>       0.01      99.00 us      99.00 us      99.00 us              1
> GETXATTR
>
>       0.01      68.50 us      48.00 us      89.00 us              2
> OPENDIR
>
>       0.03      84.33 us      40.00 us     164.00 us              6
> FSTAT
>
>       0.10      64.35 us      34.00 us     177.00 us             23
> STATFS
>
>       0.16      62.87 us      29.00 us     172.00 us             38
> STAT
>
>       0.17      54.76 us      22.00 us     194.00 us             46
> ENTRYLK
>
>       0.18      41.66 us      24.00 us      95.00 us             62
> FLUSH
>
>       0.22     198.44 us     138.00 us     339.00 us             16
> CREATE
>
>       0.32     101.65 us      65.00 us     184.00 us             46
> OPEN
>
>       0.35     726.43 us     350.00 us    1165.00 us              7
> UNLINK
>
>       0.52      56.22 us      25.00 us     228.00 us            136
> FINODELK
>
>       0.77     129.15 us      49.00 us    1138.00 us             87
> READ
>
>       1.57     154.70 us      59.00 us     360.00 us            148
> FXATTROP
>
>       2.44     159.13 us      41.00 us    5836.00 us            224
> WRITE
>
>       3.64     188.62 us      54.00 us     848.00 us            282
> LOOKUP
>
>      89.50   20741.70 us    9457.00 us   84733.00 us             63
> FSYNC
>
>     Duration: 362318 seconds
>
>    Data Read: 2132763575 <(213)%20276-3575> bytes
>
> Data Written: 83056358475 bytes
>
> Interval 0 Stats:
>
>    Block Size:                  2b+
> 4b+                   8b+
>
>  No. of Reads:                    0
> 0                     0
>
> No. of Writes:                    1
> 1                    31
>
>
>
>    Block Size:                 16b+                  32b+
> 64b+
>
>  No. of Reads:                    0
> 1                     0
>
> No. of Writes:                   20                  4283
> 3085
>
>
>
>    Block Size:                128b+                 256b+
> 512b+
>
>  No. of Reads:                    0
> 1                     0
>
> No. of Writes:                  395
> 465                   555
>
>
>
>    Block Size:               1024b+                2048b+
> 4096b+
>
>  No. of Reads:                    4
> 6                    32
>
> No. of Writes:                72453                 62462
> 52882
>
>
>
>    Block Size:               8192b+               16384b+
> 32768b+
>
>  No. of Reads:                  154
> 281                   484
>
> No. of Writes:                43122                 21700
> 17817
>
>
>
>    Block Size:              65536b+              131072b+
>
>  No. of Reads:                  993                 15290
>
> No. of Writes:                56237                581071
>
>  %-latency   Avg-latency   Min-Latency   Max-Latency   No. of
> calls         Fop
>
> ---------   -----------   -----------   -----------   ------------
> ----
>
>       0.00       0.00 us       0.00 us       0.00 us         205094
> FORGET
>
>       0.00       0.00 us       0.00 us       0.00 us         245895
> RELEASE
>
>       0.00       0.00 us       0.00 us       0.00 us          40492
> RELEASEDIR
>
>       0.00      20.50 us      19.00 us      22.00 us              2
> FSYNCDIR
>
>       0.01      99.00 us      99.00 us      99.00 us              1
> GETXATTR
>
>       0.01      68.50 us      48.00 us      89.00 us              2
> OPENDIR
>
>       0.03      84.33 us      40.00 us     164.00 us              6
> FSTAT
>
>       0.10      64.35 us      34.00 us     177.00 us             23
> STATFS
>
>       0.16      62.87 us      29.00 us     172.00 us             38
> STAT
>
>       0.17      54.76 us      22.00 us     194.00 us             46
> ENTRYLK
>
>       0.18      41.66 us      24.00 us      95.00 us             62
> FLUSH
>
>       0.22     198.44 us     138.00 us     339.00 us             16
> CREATE
>
>       0.32     101.65 us      65.00 us     184.00 us             46
> OPEN
>
>       0.35     726.43 us     350.00 us    1165.00 us              7
> UNLINK
>
>       0.52      56.22 us      25.00 us     228.00 us            136
> FINODELK
>
>       0.77     129.15 us      49.00 us    1138.00 us             87
> READ
>
>       1.57     154.70 us      59.00 us     360.00 us            148
> FXATTROP
>
>       2.44     159.13 us      41.00 us    5836.00 us            224
> WRITE
>
>       3.64     188.62 us      54.00 us     848.00 us            282
> LOOKUP
>
>      89.50   20741.70 us    9457.00 us   84733.00 us             63
> FSYNC
>
>     Duration: 362318 seconds
>
>    Data Read: 2132763575 <(213)%20276-3575> bytes
>
> Data Written: 83056358475 bytes
>
> Brick: 10.10.0.101:/glusterfsvolumes/devops/devops-prometheus/brick
>
> -------------------------------------------------------------------
>
> Cumulative Stats:
>
>    Block Size:                  2b+
> 4b+                   8b+
>
>  No. of Reads:                    0                     0
>          0
>
> No. of Writes:                    1
> 1                    31
>
>
>
>    Block Size:                 16b+                  32b+
> 64b+
>
>  No. of Reads:                    0
> 0                     0
>
> No. of Writes:                   20                  4283
> 3085
>
>
>
>    Block Size:                128b+                 256b+
> 512b+
>
>  No. of Reads:                    1
> 3                     2
>
> No. of Writes:                  395
> 465                   555
>
>
>
>    Block Size:               1024b+                2048b+
> 4096b+
>
>  No. of Reads:                    2
> 14                    22
>
> No. of Writes:                72453                 62462
> 52882
>
>
>
>    Block Size:               8192b+               16384b+
> 32768b+
>
>  No. of Reads:                  166
> 253                   502
>
> No. of Writes:                43122                 21700
> 17817
>
>
>
>    Block Size:              65536b+              131072b+
>
>  No. of Reads:                  893                 14392
>
> No. of Writes:                56237                581071
>
>  %-latency   Avg-latency   Min-Latency   Max-Latency   No. of
> calls         Fop
>
> ---------   -----------   -----------   -----------   ------------
> ----
>
>       0.00       0.00 us       0.00 us       0.00 us         205094
> FORGET
>
>       0.00       0.00 us       0.00 us       0.00 us         245861
> RELEASE
>
>       0.00       0.00 us       0.00 us       0.00 us          40492
> RELEASEDIR
>
>       0.01      89.00 us      89.00 us      89.00 us              1
> GETXATTR
>
>       0.02      62.00 us      53.00 us      71.00 us              2
> OPENDIR
>
>       0.02      57.00 us      51.00 us      61.00 us              3
> FSTAT
>
>       0.04     178.00 us      38.00 us     318.00 us              2
> FSYNCDIR
>
>       0.12     474.00 us     451.00 us     497.00 us              2
> READDIRP
>
>       0.18      64.00 us      28.00 us     113.00 us             23
> STATFS
>
>       0.28      48.30 us      18.00 us     184.00 us             46
> ENTRYLK
>
>       0.31      41.33 us      18.00 us      87.00 us             60
> FLUSH
>
>       0.33      66.12 us      28.00 us     246.00 us             40
> STAT
>
>       0.57     102.39 us      62.00 us     236.00 us             44
> OPEN
>
>       0.58     664.86 us     311.00 us     855.00 us              7
> UNLINK
>
>       0.86      51.37 us      22.00 us     101.00 us            134
> FINODELK
>
>       1.07     118.28 us      46.00 us     437.00 us             72
> READ
>
>       3.83     137.39 us      41.00 us    2431.00 us            222
> WRITE
>
>       4.54     250.94 us      57.00 us   15444.00 us            144
> FXATTROP
>
>       5.89    2932.56 us     134.00 us   17675.00 us             16
> CREATE
>
>       7.83     224.34 us      61.00 us   12509.00 us            278
> LOOKUP
>
>      73.50    9592.56 us    6897.00 us   36321.00 us             61
> FSYNC
>
>     Duration: 362152 seconds
>
>    Data Read: 2005452176 bytes
>
> Data Written: 83056358475 bytes
>
> Interval 0 Stats:
>
>    Block Size:                  2b+
> 4b+                   8b+
>
>  No. of Reads:                    0
> 0                     0
>
> No. of Writes:                    1
> 1                    31
>
>
>
>    Block Size:                 16b+                  32b+
> 64b+
>
>  No. of Reads:                    0
> 0                     0
>
> No. of Writes:                   20                  4283
> 3085
>
>
>
>    Block Size:                128b+                 256b+
> 512b+
>
>  No. of Reads:                    1
> 3                     2
>
> No. of Writes:                  395
> 465                   555
>
>
>
>    Block Size:               1024b+                2048b+
> 4096b+
>
>  No. of Reads:                    2
>          14                    22
>
> No. of Writes:                72453                 62462
> 52882
>
>
>
>    Block Size:               8192b+               16384b+
> 32768b+
>
>  No. of Reads:                  166
> 253                   502
>
> No. of Writes:                43122                 21700
> 17817
>
>
>
>    Block Size:              65536b+              131072b+
>
>  No. of Reads:                  893                 14392
>
> No. of Writes:                56237                581071
>
>  %-latency   Avg-latency   Min-Latency   Max-Latency   No. of
> calls         Fop
>
> ---------   -----------   -----------   -----------   ------------
> ----
>
>       0.00       0.00 us       0.00 us       0.00 us         205094
> FORGET
>
>       0.00       0.00 us       0.00 us       0.00 us         245861
> RELEASE
>
>       0.00       0.00 us       0.00 us       0.00 us          40492
> RELEASEDIR
>
>       0.01      89.00 us      89.00 us      89.00 us              1
> GETXATTR
>
>       0.02      62.00 us      53.00 us      71.00 us              2
> OPENDIR
>
>       0.02      57.00 us      51.00 us      61.00 us              3
> FSTAT
>
>       0.04     178.00 us      38.00 us     318.00 us              2
> FSYNCDIR
>
>       0.12     474.00 us     451.00 us     497.00 us              2
> READDIRP
>
>       0.18      64.00 us      28.00 us     113.00 us             23
> STATFS
>
>       0.28      48.30 us      18.00 us     184.00 us             46
> ENTRYLK
>
>       0.31      41.33 us      18.00 us      87.00 us             60
> FLUSH
>
>       0.33      66.12 us      28.00 us     246.00 us             40
> STAT
>
>       0.57     102.39 us      62.00 us     236.00 us             44
> OPEN
>
>       0.58     664.86 us     311.00 us     855.00 us              7
> UNLINK
>
>       0.86      51.37 us      22.00 us     101.00 us            134
> FINODELK
>
>       1.07     118.28 us      46.00 us     437.00 us             72
> READ
>
>       3.83     137.39 us      41.00 us    2431.00 us            222
> WRITE
>
>       4.54     250.94 us      57.00 us   15444.00 us            144
> FXATTROP
>
>       5.89    2932.56 us     134.00 us   17675.00 us             16
> CREATE
>
>       7.83     224.34 us      61.00 us   12509.00 us            278
> LOOKUP
>
>      73.50    9592.56 us    6897.00 us   36321.00 us             61
> FSYNC
>
>     Duration: 362152 seconds
>
>    Data Read: 2005452176 bytes
>
> Data Written: 83056358475 bytes
>
>
>
>
>
> Seems latency of FSYNC is very high. Sometimes cpu wait is also very high:
>
>
>
> top - 15:27:39 up 4 days,  4:58,  2 users,  load average: 0.75, 0.72, 0.70
>
> Tasks: 210 total,   1 running, 209 sleeping,   0 stopped,   0 zombie
>
> %Cpu(s):  0.3 us,  0.2 sy,  0.0 ni, 62.9 id, *36.5* wa,  0.0 hi,  0.1
> si,  0.0 st
>
> KiB Mem :  8043984 total,   883420 free,  1788912 used,  5371652 buff/cache
>
> KiB Swap:        0 total,        0 free,        0 used.  5819396 avail Mem
>
> Any ideas?
>
>
>
> Thanks.
>
> _______________________________________________
> Gluster-users mailing list
> Gluster-users at gluster.org
> http://lists.gluster.org/mailman/listinfo/gluster-users
>
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