#!/bin/sh
# A port of ZFS stats for FreeBSD plugin to Linux
# Author of the original plugin: David Bjornsson <dabb@lolnet.is>
# Author of the Linux port: Alex Chistyakov <alexclear@gmail.com>
#
# Usage: zfs_stats_FUNCTION
#
# Available functions:
#	efficiency - ARC efficiency
#	cachehitlist - Cache hit by cache list
#	cachehitdtype - Cache hit by data type
#	utilization - ARC size breakdown
#	l2utilization - L2ARC size breakdown
#	l2efficiency - L2ARC efficiency
#
#%# family=auto

FUNCTION=$(basename $0 | cut -d_ -f3)
BC='/usr/bin/bc -q'
SYS='/sbin/sysctl -n'

#
# Sysctl macros
#


CONTENT=`cat /proc/spl/kstat/zfs/arcstats`

ARC_HITS=`echo "$CONTENT" | grep "^hits" | awk '{print $3;}'`

ARC_MISSES=`echo "$CONTENT" | grep "^misses" | awk '{print $3;}'`

DEMAND_DATA_HITS=`echo "$CONTENT" | grep "^demand_data_hits" | awk '{print $3;}'`
DEMAND_DATA_MISSES=`echo "$CONTENT" | grep "^demand_data_misses" | awk '{print $3;}'`
DEMAND_METADATA_HITS=`echo "$CONTENT" | grep "^demand_metadata_hits" | awk '{print $3;}'`
DEMAND_METADATA_MISSES=`echo "$CONTENT" | grep "^demand_metadata_misses" | awk '{print $3;}'`

MFU_GHOST_HITS=`echo "$CONTENT" | grep "^mfu_ghost_hits" | awk '{print $3;}'`
MFU_HITS=`echo "$CONTENT" | grep "^mfu_hits" | awk '{print $3;}'`
MRU_GHOST_HITS=`echo "$CONTENT" | grep "^mru_ghost_hits" | awk '{print $3;}'`
MRU_HITS=`echo "$CONTENT" | grep "^mru_hits" | awk '{print $3;}'`

PREFETCH_DATA_HITS=`echo "$CONTENT" | grep "^prefetch_data_hits" | awk '{print $3;}'`
PREFETCH_DATA_MISSES=`echo "$CONTENT" | grep "^prefetch_data_misses" | awk '{print $3;}'`
PREFETCH_METADATA_HITS=`echo "$CONTENT" | grep "^prefetch_metadata_hits" | awk '{print $3;}'`
PREFETCH_METADATA_MISSES=`echo "$CONTENT" | grep "^prefetch_metadata_misses" | awk '{print $3;}'`

SIZE=`echo "$CONTENT" | grep "^size" | awk '{print $3;}'`
MRU_SIZE=`echo "$CONTENT" | grep "^p\s" | awk '{print $3;}'`
MAX_SIZE=`echo "$CONTENT" | grep "^c_max" | awk '{print $3;}'`
MIN_SIZE=`echo "$CONTENT" | grep "^c_min" | awk '{print $3;}'`
TARGET_SIZE=`echo "$CONTENT" | grep "^c\s" | awk '{print $3;}'`

L2_SIZE=`echo "$CONTENT" | grep "^l2_size" | awk '{print $3;}'`
L2_HDR_SIZE=`echo "$CONTENT" | grep "^l2_hdr_size" | awk '{print $3;}'`

L2_HITS=`echo "$CONTENT" | grep "^l2_hits" | awk '{print $3;}'`
L2_MISSES=`echo "$CONTENT" | grep "^l2_misses" | awk '{print $3;}'`

#
# Calculation macros
#

ANON_HITS=`echo "$ARC_HITS-($MFU_HITS+$MRU_HITS+$MFU_GHOST_HITS+$MRU_GHOST_HITS)" | $BC`
ARC_ACCESSES_TOTAL=`echo "$ARC_HITS+$ARC_MISSES" | $BC`
DEMAND_DATA_TOTAL=`echo "$DEMAND_DATA_HITS+$DEMAND_DATA_MISSES" | $BC`
PREFETCH_DATA_TOTAL=`echo "$PREFETCH_DATA_HITS+$PREFETCH_DATA_MISSES" | $BC`
REAL_HITS=`echo "$MFU_HITS+$MRU_HITS" | $BC`

CACHE_HIT_RATIO_PERC=`echo "scale=2 ; (100*$ARC_HITS/$ARC_ACCESSES_TOTAL)" | $BC`
CACHE_MISS_RATIO_PERC=`echo "scale=2 ; (100*$ARC_MISSES/$ARC_ACCESSES_TOTAL)" | $BC`
ACTUAL_HIT_RATIO_PERC=`echo "scale=2 ; (100*$REAL_HITS/$ARC_ACCESSES_TOTAL)" | $BC`
DATA_DEMAND_EFFICIENCY_PERC=`echo "scale=2 ; (100*$DEMAND_DATA_HITS/$DEMAND_DATA_TOTAL)" | $BC`
DATA_PREFETCH_EFFICENCY_PERC=`echo "scale=2 ; (100*$PREFETCH_DATA_HITS/$PREFETCH_DATA_TOTAL)" | $BC`

ANONYMOUSLY_USED_PERC=`echo "scale=2 ; (100*$ANON_HITS/$ARC_HITS)" | $BC`
MOST_RECENTLY_USED_PERC=`echo "scale=2 ; (100*$MRU_HITS/$ARC_HITS)" | $BC`
MOST_FREQUENTLY_USED_PERC=`echo "scale=2 ; (100*$MFU_HITS/$ARC_HITS)" | $BC`
MOST_RECENTLY_USED_GHOST_PERC=`echo "scale=2 ; (100*$MRU_GHOST_HITS/$ARC_HITS)" | $BC`
MOST_FREQUENTLY_USED_GHOST_PERC=`echo "scale=2 ; (100*$MFU_GHOST_HITS/$ARC_HITS)" | $BC`

DEMAND_DATA_HIT_PERC=`echo "scale=2 ; (100*$DEMAND_DATA_HITS/$ARC_HITS)" | $BC`
DEMAND_DATA_MISS_PERC=`echo "scale=2 ; (100*$DEMAND_DATA_MISSES/$ARC_MISSES)" | $BC`
PREFETCH_DATA_HIT_PERC=`echo "scale=2 ; (100*$PREFETCH_DATA_HITS/$ARC_HITS)" | $BC`
PREFETCH_DATA_MISS_PERC=`echo "scale=2 ; (100*$PREFETCH_DATA_MISSES/$ARC_MISSES)" | $BC`
DEMAND_METADATA_HIT_PERC=`echo "scale=2 ; (100*$DEMAND_METADATA_HITS/$ARC_HITS)" | $BC`
DEMAND_METADATA_MISS_PERC=`echo "scale=2 ; (100*$DEMAND_METADATA_MISSES/$ARC_MISSES)" | $BC`
PREFETCH_METADATA_HIT_PERC=`echo "scale=2 ; (100*$PREFETCH_METADATA_HITS/$ARC_HITS)" | $BC`
PREFETCH_METADATA_MISSES_PERC=`echo "scale=2 ; (100*$PREFETCH_METADATA_MISSES/$ARC_MISSES)" | $BC`

if [ $SIZE -gt $TARGET_SIZE ]; then
	MFU_SIZE=`echo "$SIZE-$MRU_SIZE" | $BC`
else
	MFU_SIZE=`echo "$TARGET_SIZE-$MRU_SIZE" | $BC`
fi

L2_ACCESSES_TOTAL=`echo "$L2_HITS+$L2_MISSES" | $BC`
if [ $L2_ACCESSES_TOTAL -gt 0 ]; then
	L2_HIT_RATIO_PERC=`echo "scale=2 ; (100*$L2_HITS/$L2_ACCESSES_TOTAL)" | $BC`
	L2_MISS_RATIO_PERC=`echo "scale=2 ; (100*$L2_MISSES/$L2_ACCESSES_TOTAL)" | $BC`
fi

efficiency() {
        if [ "$1" = "config" ]; then
                echo 'graph_title ZFS ARC Efficiency'
                echo 'graph_args -u 100'
                echo 'graph_vlabel %'
                echo 'graph_info This graph shows the ARC Efficiency'

                echo 'hits.label Hit Ratio'
                echo 'misses.label Miss Ratio'
                echo 'actual_hits.label Actual Hit Ratio'
                echo 'data_demand_efficiency.label Data Demand Efficiency'
                echo 'data_prefetch_efficiency.label Data Prefetch Efficiency'

		exit 0
        else
                echo 'hits.value ' $CACHE_HIT_RATIO_PERC
                echo 'misses.value ' $CACHE_MISS_RATIO_PERC
                echo 'actual_hits.value ' $ACTUAL_HIT_RATIO_PERC
                echo 'data_demand_efficiency.value ' $DATA_DEMAND_EFFICIENCY_PERC
                echo 'data_prefetch_efficiency.value ' $DATA_PREFETCH_EFFICENCY_PERC
        fi
}

cachehitlist() {
        if [ "$1" = "config" ]; then
                echo 'graph_title ZFS ARC Efficiency: Cache hits by cache list'
                echo 'graph_args -u 100'
                echo 'graph_vlabel %'
                echo 'graph_info This graph shows the ARC Efficiency'

                echo 'cache_list_anon.label Anonymously Used'
                echo 'cache_list_most_rec.label Most Recently Used'
                echo 'cache_list_most_freq.label Most Frequently Used'
                echo 'cache_list_most_rec_ghost.label Most Recently Used Ghost'
                echo 'cache_list_most_freq_ghost.label Most Frequently Used Ghost'

		exit 0
	else
                echo 'cache_list_anon.value ' $ANONYMOUSLY_USED_PERC
                echo 'cache_list_most_rec.value ' $MOST_RECENTLY_USED_PERC
                echo 'cache_list_most_freq.value ' $MOST_FREQUENTLY_USED_PERC
                echo 'cache_list_most_rec_ghost.value ' $MOST_RECENTLY_USED_GHOST_PERC
                echo 'cache_list_most_freq_ghost.value ' $MOST_FREQUENTLY_USED_GHOST_PERC
	fi
}

cachehitdtype() {
        if [ "$1" = "config" ]; then
                echo 'graph_title ZFS ARC Efficiency: Cache hits by data type'
                echo 'graph_args -u 100'
                echo 'graph_vlabel %'
                echo 'graph_info This graph shows the ARC Efficiency'

                echo 'data_type_demand_hits.label Demand Data Hit Ratio'
                echo 'data_type_demand_misses.label Demand Data Miss Ratio'
                echo 'data_type_prefetch_hits.label Prefetch Data Hit Ratio'
                echo 'data_type_prefetch_misses.label Prefetch Data Miss Ratio'
                echo 'data_type_demand_metadata_hits.label Demand Metadata Hit Ratio'
                echo 'data_type_demand_metadata_misses.label Demand Metadata Miss Ratio'
                echo 'data_type_prefetch_metadata_hits.label Prefetch Metadata Hit Ratio'
                echo 'data_type_prefetch_metadata_misses.label Prefetch Metadata Miss Ratio'

		exit 0
	else
                echo 'data_type_demand_hits.value ' $DEMAND_DATA_HIT_PERC
                echo 'data_type_demand_misses.value ' $DEMAND_DATA_MISS_PERC
                echo 'data_type_prefetch_hits.value ' $PREFETCH_DATA_HIT_PERC
                echo 'data_type_prefetch_misses.value ' $PREFETCH_DATA_MISS_PERC
                echo 'data_type_demand_metadata_hits.value ' $DEMAND_METADATA_HIT_PERC
                echo 'data_type_demand_metadata_misses.value ' $DEMAND_METADATA_MISS_PERC
                echo 'data_type_prefetch_metadata_hits.value ' $PREFETCH_METADATA_HIT_PERC
                echo 'data_type_prefetch_metadata_misses.value ' $PREFETCH_METADATA_MISSES_PERC
	fi
}

utilization() {
        if [ "$1" = "config" ]; then
                echo 'graph_title ZFS ARC Size'
                echo 'graph_args --base 1024 -l 0 --vertical-label Bytes'
                echo 'graph_vlabel Size in MB'
                echo 'graph_info This graph shows the ARC Size utilization'

                echo 'max_size.label Maximum Size'
		echo 'max_size.draw AREA'
                echo 'size.label Size'
                echo 'size.draw AREA'
                echo 'min_size.label Minimum Size'
                echo 'min_size.draw AREA'
                echo 'target_size.label Target Size'
                echo 'target_size.draw LINE1'
		echo 'recently_size.label Recently Used Cache Size'
		echo 'recently_size.draw LINE1'
		echo 'frequently_size.label Frequently Used Cache Size'
		echo 'frequently_size.draw LINE1'

		exit 0
	else
                echo 'max_size.value ' $MAX_SIZE
		echo 'size.value ' $SIZE
                echo 'min_size.value ' $MIN_SIZE
                echo 'target_size.value ' $TARGET_SIZE
		echo 'recently_size.value ' $MRU_SIZE
		echo 'frequently_size.value ' $MFU_SIZE
	fi
}

l2utilization() {
        if [ "$1" = "config" ]; then
                echo 'graph_title ZFS L2ARC Size'
                echo 'graph_args --base 1024 -r -l 0 --vertical-label Bytes'
                echo 'graph_vlabel Size in MB'
                echo 'graph_info This graph shows the L2ARC Size utilization'

                echo 'size.label Size'
                echo 'size.draw AREA'
                echo 'hdr_size.label Header Size'
                echo 'hdr_size.draw AREA'

                exit 0
        else
                echo 'size.value ' $L2_SIZE
                echo 'hdr_size.value ' $L2_HDR_SIZE
        fi
}

l2efficiency() {
	if [ "$1" = "config" ]; then
		echo 'graph_title ZFS L2ARC Efficiency'
                echo 'graph_args -u 100'
                echo 'graph_vlabel %'
                echo 'graph_info This graph shows the L2ARC Efficiency'

		echo 'l2_hits.label Hit Ratio'
		echo 'l2_misses.label Miss Ratio'
	else
		echo 'l2_hits.value ' $L2_HIT_RATIO_PERC
		echo 'l2_misses.value ' $L2_MISS_RATIO_PERC
	fi

}

[ "$1" = "config" ] && echo "graph_category zfs"

case "$FUNCTION" in
        efficiency)
                efficiency $1
                ;;
        cachehitlist)
                cachehitlist $1
                ;;
        cachehitdtype)
                cachehitdtype $1
                ;;
        utilization)
                utilization $1
                ;;
	l2utilization)
		l2utilization $1
		;;
	l2efficiency)
		l2efficiency $1
		;;
esac