/usr/lib/pcp/bin/pcp-dmcache is in pcp 4.0.1-1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 | #!/usr/bin/env pmpython
#
# Copyright (C) 2014-2017 Red Hat.
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# DmCache Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
# for more details.
#
# pylint: disable=C0103,R0914,R0902,W0141
""" Display device mapper cache statistics for the system """
import sys
from pcp import pmapi, pmcc
if sys.version >= '3':
long = int # python2 to python3 portability (no long() in python3)
CACHE_METRICS = ['dmcache.cache.used', 'dmcache.cache.total',
'dmcache.metadata.used', 'dmcache.metadata.total',
'dmcache.read_hits', 'dmcache.read_misses',
'dmcache.write_hits', 'dmcache.write_misses',
'disk.dm.read', 'disk.dm.write']
HEADING = ''
COL_HEADING = \
' ---%used--- ---------reads--------- --------writes---------'
SUBHEAD_IOPS = \
' meta cache hit miss ops hit miss ops'
SUBHEAD_RATIO = \
' meta cache hit miss ratio hit miss ratio'
RATIO = True # default to displaying cache hit ratios
REPEAT = 10 # repeat heading after every N samples
def option(opt, optarg, index):
""" Perform setup for an individual command line option """
global RATIO
global REPEAT
if opt == 'R':
REPEAT = int(optarg)
elif opt == 'i':
RATIO = False
def cache_value(group, device, width, values):
""" Lookup value for device instance, return it in a short string """
if device not in values:
return '?'.rjust(width)
result = group.contextCache.pmNumberStr(values[device])
return result.strip(' ').rjust(width)
def cache_percent(device, width, used, total):
""" From used and total values (dict), calculate 'percentage used' """
if device not in used or device not in total:
return '?%'.rjust(width)
numerator = float(used[device])
denominator = float(total[device])
if denominator == 0.0:
return '0%'.rjust(width)
value = 100.0 * numerator / denominator
if value >= 100.0:
return '100%'.rjust(width)
return ('%3.1f%%' % value).rjust(width)
def cache_dict(group, metric):
""" Create an instance:value dictionary for the given metric """
values = group[metric].netConvValues
if not values:
return {}
return dict(map(lambda x: (x[1], x[2]), values))
def max_lv_length(group):
""" look at the observation group and return the max length of all the lvnames """
cache_used = cache_dict(group, 'dmcache.cache.used')
if not cache_used:
return 0
lv_names = cache_used.keys()
return len(max(lv_names, key=len))
class DmCachePrinter(pmcc.MetricGroupPrinter):
""" Report device mapper cache statistics """
def __init__(self, devices):
""" Construct object - prepare for command line handling """
pmcc.MetricGroupPrinter.__init__(self)
self.hostname = None
self.devices = devices
def report_values(self, group, width=12):
""" Report values for one of more device mapper cache devices """
# Build several dictionaries, keyed on cache names, with the values
cache_used = cache_dict(group, 'dmcache.cache.used')
cache_total = cache_dict(group, 'dmcache.cache.total')
meta_used = cache_dict(group, 'dmcache.metadata.used')
meta_total = cache_dict(group, 'dmcache.metadata.total')
read_hits = cache_dict(group, 'dmcache.read_hits')
read_misses = cache_dict(group, 'dmcache.read_misses')
read_ops = cache_dict(group, 'disk.dm.read')
write_hits = cache_dict(group, 'dmcache.write_hits')
write_misses = cache_dict(group, 'dmcache.write_misses')
write_ops = cache_dict(group, 'disk.dm.write')
devicelist = self.devices
if not devicelist:
devicelist = cache_used.keys()
if devicelist:
for name in sorted(devicelist):
if RATIO:
read_column = cache_percent(name, 7, read_hits, read_ops)
write_column = cache_percent(name, 7, write_hits, write_ops)
else:
read_column = cache_value(group, name, 7, read_ops)
write_column = cache_value(group, name, 7, write_ops)
print('%s %s %s %s %s %s %s %s %s' % (name[:width],
cache_percent(name, 5, meta_used, meta_total),
cache_percent(name, 5, cache_used, cache_total),
cache_value(group, name, 7, read_hits),
cache_value(group, name, 7, read_misses),
read_column,
cache_value(group, name, 7, write_hits),
cache_value(group, name, 7, write_misses),
write_column))
else:
print('No values available')
def report(self, groups):
""" Report driver routine - headings, sub-headings and values """
self.convert(groups)
group = groups['dmcache']
max_lv = max_lv_length(group)
padding = " "*max_lv
if groups.counter % REPEAT == 1:
if not self.hostname:
self.hostname = group.contextCache.pmGetContextHostName()
stamp = group.contextCache.pmCtime(long(group.timestamp))
title = '@ %s (host %s)' % (stamp.rstrip(), self.hostname)
if RATIO:
style = "%s%s" % (padding, SUBHEAD_RATIO)
else:
style = "%s%s" % (padding, SUBHEAD_IOPS)
HEADING = ' device '.center(max_lv,'-') + COL_HEADING
print('%s\n%s\n%s' % (title, HEADING, style))
self.report_values(group, width=max_lv)
if __name__ == '__main__':
try:
options = pmapi.pmOptions('iR:?')
options.pmSetShortUsage('[options] [device ...]')
options.pmSetOptionCallback(option)
options.pmSetLongOptionHeader('Options')
options.pmSetLongOption('repeat', 1, 'R', 'N', 'repeat the header after every N samples')
options.pmSetLongOption('iops', 0, 'i', '', 'display IOPs instead of cache hit ratio')
options.pmSetLongOptionVersion()
options.pmSetLongOptionHelp()
manager = pmcc.MetricGroupManager.builder(options, sys.argv)
missing = manager.checkMissingMetrics(CACHE_METRICS)
if missing != None:
sys.stderr.write('Error: not all required metrics are available\nMissing: %s\n' % (missing))
sys.exit(1)
manager.printer = DmCachePrinter(options.pmGetOperands())
manager['dmcache'] = CACHE_METRICS
manager.run()
except pmapi.pmErr as error:
print('%s: %s\n' % (error.progname(), error.message()))
except pmapi.pmUsageErr as usage:
usage.message()
except KeyboardInterrupt:
pass
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