mackerel-plugin-linux dose not outputs about disk stats.

[azusa]

mackerel-plugin-linux dose not outputs about disk stats.

• custom.linux.disk.elapsed.*
• custom.linux.disk.rwtime.*

command output is here:

$ mackerel-plugin-linux                                                     [~]
2020/07/22 22:22:11 OutputValues:  Too long duration
linux.users.users       2.000000        1595424131
2020/07/22 22:22:11 OutputValues:  Too long duration
2020/07/22 22:22:11 OutputValues:  Too long duration
linux.ss.ESTAB  135.000000      1595424131
linux.ss.TIME-WAIT      3.000000        1595424131
linux.ss.UNCONN 42.000000       1595424131
linux.ss.LISTEN 27.000000       1595424131
2020/07/22 22:22:11 OutputValues:  Too long duration
2020/07/22 22:22:11 OutputValues:  Too long duration

mackerel-plungin-linux expects /sys/block/*/stat has just 11 fields.¹
Otherwise some OSs /sys/block/*/stat has more than 11 fields, then function in mackerel-plungin-linux returns err.

[]:$ cat /etc/os-release                                                       [~]
PRETTY_NAME="Raspbian GNU/Linux 10 (buster)"
NAME="Raspbian GNU/Linux"
VERSION_ID="10"
VERSION="10 (buster)"
VERSION_CODENAME=buster
ID=raspbian
ID_LIKE=debian
HOME_URL="http://www.raspbian.org/"
SUPPORT_URL="http://www.raspbian.org/RaspbianForums"
BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"
[]:$ uname -a                                                                  [~]
Linux pidev 4.19.118-v7l+ #1311 SMP Mon Apr 27 14:26:42 BST 2020 armv7l GNU/Linux
[]:$ readlink -f  /sys/block/mmcblk0/stat                                      [~]
/sys/devices/platform/emmc2bus/fe340000.emmc2/mmc_host/mmc0/mmc0:1234/block/mmcblk0/stat
[]:$ cat $(readlink -f  /sys/block/mmcblk0/stat)                               [~]
    6805     9720   543404    89110    18930    15212   508826  4115817        0   919500  1424010        0        0        0 

$ cat /etc/os-release
NAME="CentOS Linux"
VERSION="8 (Core)"
ID="centos"
ID_LIKE="rhel fedora"
VERSION_ID="8"
PLATFORM_ID="platform:el8"
PRETTY_NAME="CentOS Linux 8 (Core)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:centos:centos:8"
HOME_URL="https://www.centos.org/"
BUG_REPORT_URL="https://bugs.centos.org/"

CENTOS_MANTISBT_PROJECT="CentOS-8"
CENTOS_MANTISBT_PROJECT_VERSION="8"
REDHAT_SUPPORT_PRODUCT="centos"
REDHAT_SUPPORT_PRODUCT_VERSION="8"

$ uname -a
Linux localhost.localdomain 4.18.0-193.6.3.el8_2.x86_64 #1 SMP Wed Jun 10 11:09:32 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
$ readlink -f /sys/block/sda/stat
/sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/00000000-0000-8899-0000-000000000000/host0/target0:0:0/0:0:0:0/block/sda/stat
$ cat $(readlink -f /sys/block/sda/stat)
    5260        2   431891     3300      545      129   114704      765        0     3625     1822        0
   0        0        0

Footnotes

1. https://github.com/mackerelio/mackerel-agent-plugins/blob/3bb5f6abae5b1acc776d8cc0690af457b14f7d3e/mackerel-plugin-linux/lib/linux.go#L334 ↩

[astj]

Thank you for report!

According to iostat documentation in Linux git repo, the format is changed at kernel 4.18.
So I suspect (but not yet confirmed) that mackerel-plugin-linux does not output disk-stat-related metrics with those newer kernels.
I'll prepare fix for this.

[astj]

@azusa Hi. This problem should be fixed by #658 and released at 0.62.0 today.
So I'd like to close this issue now. (Feel free to reopen if the problem still exists)

Thank you again for reporting!