#!/bin/bash
: << =cut
=head1 NAME
zfs_arcstats - Munin multi-graph plugin to monitor ZFS ARC statistics
These functions are implemented:
size : to monitor ARC size
activity : to monitor ARC activities
actlist : to monitor ARC activities by cache list (MFU/MRU)
actdata : to monitor ARC activities by data type (Demand/Prefetch)
hitratio : to monitor ARC hit ratio
Tested with Solaris 10 and 11, OpenIndiana Hipster, FreeBSD 11, CentOS 7
This plugin is inspired by arcstat.pl [https://github.com/mharsch/arcstat]
=head1 CONFIGURATION
Make symlink:
cd /path/to/munin/etc/plugins
ln -s /path/to/munin/lib/plugins/zfs_arcstats .
For FreeBSD, it should be necessary to change shebang /bin/bash -> /usr/local/bin/bash
=head1 ENVIRONMENT VARIABLES
None
=head1 AUTHOR
K.Cima https://github.com/shakemid
=head1 LICENSE
GPLv2
=head1 Magic markers
#%# family=contrib
#%# capabilities=autoconf
=cut
# Include plugin.sh
. "${MUNIN_LIBDIR:-}/plugins/plugin.sh"
is_multigraph "$@"
# Shell options
set -o nounset
# Set global variables
plugin_name=zfs_arcstats
functions='size activity actlist actdata hitratio'
# Functions
get_osname() {
local osname osver
osname=$( uname -s )
osver=$( uname -v )
case $osname in
SunOS)
case $osver in
illumos*)
osname=illumos
;;
esac
;;
esac
echo "$osname"
}
preconfig() {
local func=$1
# data_attr format: field type draw label
# label can contain white-spaces.
case $func in
size)
global_attr="
graph_title ZFS ARC - Size
graph_category fs
graph_args --base 1024 --lower-limit 0
graph_vlabel Bytes
graph_info ZFS ARC - Size
"
case $osname in
SunOS)
# For Solaris 10,11
data_attr="
data_size GAUGE AREASTACK Data size
prefetch_meta_size GAUGE AREASTACK Prefetch meta size
buf_size GAUGE AREASTACK Buf size
other_size GAUGE AREASTACK Other size
"
;;
*)
# For illumos, FreeBSD, Linux (OpenZFS)
data_attr="
data_size GAUGE AREASTACK Data size
metadata_size GAUGE AREASTACK Metadata size
hdr_size GAUGE AREASTACK Hdr size
other_size GAUGE AREASTACK Other size
mru_size GAUGE LINE MRU size
mfu_size GAUGE LINE MFU size
"
;;
esac
data_attr="
$data_attr
size GAUGE LINE ARC size
c GAUGE LINE Target size
p GAUGE LINE Target MRU size
"
;;
activity)
global_attr="
graph_title ZFS ARC - Activities
graph_category fs
graph_args --base 1000 --lower-limit 0
graph_vlabel misses (-) / hits (+) per second
graph_info ZFS ARC - Activities
hits.negative misses
l2_hits.negative l2_misses
"
data_attr="
misses DERIVE LINE dummy
hits DERIVE LINE ARC
l2_misses DERIVE LINE dummy
l2_hits DERIVE LINE L2ARC
"
;;
actlist)
global_attr="
graph_title ZFS ARC - Activities by cache list
graph_category fs
graph_args --base 1000 --lower-limit 0
graph_vlabel ghost hits (-) / hits (+) per second
graph_info ZFS ARC - Activities by cache list
mfu_hits.negative mfu_ghost_hits
mru_hits.negative mru_ghost_hits
"
data_attr="
mfu_ghost_hits DERIVE LINE dummy
mfu_hits DERIVE LINE MFU
mru_ghost_hits DERIVE LINE dummy
mru_hits DERIVE LINE MRU
"
;;
actdata)
global_attr="
graph_title ZFS ARC - Activities by data type
graph_category fs
graph_args --base 1000 --lower-limit 0
graph_vlabel misses (-) / hits (+) per second
graph_info ZFS ARC - Activities by data type
demand_data_hits.negative demand_data_misses
demand_metadata_hits.negative demand_metadata_misses
prefetch_data_hits.negative prefetch_data_misses
prefetch_metadata_hits.negative prefetch_metadata_misses
"
data_attr="
demand_data_misses DERIVE LINE dummy
demand_data_hits DERIVE LINE D data
demand_metadata_misses DERIVE LINE dummy
demand_metadata_hits DERIVE LINE D meta
prefetch_data_misses DERIVE LINE dummy
prefetch_data_hits DERIVE LINE P data
prefetch_metadata_misses DERIVE LINE dummy
prefetch_metadata_hits DERIVE LINE P meta
"
;;
hitratio)
global_attr="
graph_title ZFS ARC - Hit ratio
graph_category fs
graph_args --base 1000 --lower-limit 0 --upper-limit 100 --rigid
graph_vlabel % hits
graph_info ZFS ARC - Hit ratio - The graph shows cache hit ratio between munin-update intervals (usually 5 minutes).
hitratio.cdef hits,DUP,misses,+,/,100,*
l2_hitratio.cdef l2_hits,DUP,l2_misses,+,/,100,*
demand_data_hitratio.cdef demand_data_hits,DUP,demand_data_misses,+,/,100,*
demand_metadata_hitratio.cdef demand_metadata_hits,DUP,demand_metadata_misses,+,/,100,*
prefetch_data_hitratio.cdef prefetch_data_hits,DUP,prefetch_data_misses,+,/,100,*
prefetch_metadata_hitratio.cdef prefetch_metadata_hits,DUP,prefetch_metadata_misses,+,/,100,*
"
data_attr="
hits DERIVE LINE dummy
misses DERIVE LINE dummy
l2_hits DERIVE LINE dummy
l2_misses DERIVE LINE dummy
demand_data_hits DERIVE LINE dummy
demand_data_misses DERIVE LINE dummy
demand_metadata_hits DERIVE LINE dummy
demand_metadata_misses DERIVE LINE dummy
prefetch_data_hits DERIVE LINE dummy
prefetch_data_misses DERIVE LINE dummy
prefetch_metadata_hits DERIVE LINE dummy
prefetch_metadata_misses DERIVE LINE dummy
hitratio GAUGE LINE2 ARC hits
l2_hitratio GAUGE LINE L2ARC hits
demand_data_hitratio GAUGE LINE Demand data hits
demand_metadata_hitratio GAUGE LINE Demand metadata hits
prefetch_data_hitratio GAUGE LINE Prefetch data hits
prefetch_metadata_hitratio GAUGE LINE Prefetch metadata hits
"
;;
*)
echo "Unknown function: $func"
exit 1
;;
esac
}
do_config() {
local func=$1
local label_max_length=45
local field type draw label
preconfig "$func"
echo "multigraph ${plugin_name}_${func}"
# print global attributes
echo "$global_attr" | sed -e 's/^ *//' -e '/^$/d'
# print data source attributes
echo "$data_attr" | while read -r field type draw label
do
[ -z "$field" ] && continue
echo "${field}.type ${type}"
echo "${field}.draw ${draw}"
echo "${field}.label ${label:0:${label_max_length}}"
if [ "$type" = 'DERIVE' ]; then
echo "${field}.min 0"
fi
if [ "$label" = 'dummy' ]; then
echo "${field}.graph no"
fi
done
echo
}
get_stats() {
local arcstats stat value
case $osname in
SunOS|illumos)
arcstats=$( kstat -p 'zfs:0:arcstats' | sed -e 's/:/ /g' | awk '{ print $4,$5 }' )
# kstat output example:
# $ kstat -p zfs:0:arcstats
# zfs:0:arcstats:c 4135233544
# ...
;;
*BSD)
arcstats=$( /sbin/sysctl -a | sed -n -e 's/^kstat\.zfs\.misc\.arcstats\.//p' | awk -F: '{ print $1,$2 }' )
# sysctl output example:
# $ sysctl -a
# ...
# kstat.zfs.misc.arcstats.c: 632540160
# ...
;;
Linux)
arcstats=$( sed '1,2d' /proc/spl/kstat/zfs/arcstats | awk '{ print $1,$3 }' )
# proc file output example:
# $ cat /proc/spl/kstat/zfs/arcstats
# ...
# name type data
# hits 4 62
# ...
;;
*)
echo "Unsupported OS: $osname"
exit 1
esac
while read -r stat value
do
printf -v "arcstats_${stat}" "%s" "$value"
# printf -v means indirect variable assignment (similar to eval)
done <<< "$arcstats"
}
do_fetch() {
local func=$1
local field type draw label value ref
preconfig "$func"
echo "multigraph ${plugin_name}_${func}"
echo "$data_attr" | while read -r field type draw label
do
[ -z "$field" ] && continue
ref="arcstats_${field}"
value=${!ref:-0}
# ${!varname} means indirect evaluation (similar to eval)
echo "${field}.value ${value}"
done
echo
}
autoconf() {
if [ -x /sbin/zfs ]; then
echo yes
else
echo "no (ZFS looks unavailable)"
fi
}
config() {
local func
for func in $functions
do
do_config "$func"
done
}
fetch() {
local func
get_stats
for func in $functions
do
do_fetch "$func"
done
}
# Main
osname=$( get_osname )
case ${1:-} in
autoconf)
autoconf
;;
config)
config
if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
;;
*)
fetch
;;
esac
exit 0
