cmd/arcstat/arcstat.py

   1 #!/usr/local/bin/python
   2 #
   3 # Print out ZFS ARC Statistics exported via kstat(1)
   4 # For a definition of fields, or usage, use arctstat.pl -v
   5 #
   6 # This script is a fork of the original arcstat.pl (0.1) by
   7 # Neelakanth Nadgir, originally published on his Sun blog on
   8 # 09/18/2007
   9 #     http://blogs.sun.com/realneel/entry/zfs_arc_statistics
  10 #
  11 # This version aims to improve upon the original by adding features
  12 # and fixing bugs as needed.  This version is maintained by
  13 # Mike Harsch and is hosted in a public open source repository:
  14 #    http://github.com/mharsch/arcstat
  15 #
  16 # Comments, Questions, or Suggestions are always welcome.
  17 # Contact the maintainer at ( mike at harschsystems dot com )
  18 #
  19 # CDDL HEADER START
  20 #
  21 # The contents of this file are subject to the terms of the
  22 # Common Development and Distribution License, Version 1.0 only
  23 # (the "License").  You may not use this file except in compliance
  24 # with the License.
  25 #
  26 # You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  27 # or http://www.opensolaris.org/os/licensing.
  28 # See the License for the specific language governing permissions
  29 # and limitations under the License.
  30 #
  31 # When distributing Covered Code, include this CDDL HEADER in each
  32 # file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  33 # If applicable, add the following below this CDDL HEADER, with the
  34 # fields enclosed by brackets "[]" replaced with your own identifying
  35 # information: Portions Copyright [yyyy] [name of copyright owner]
  36 #
  37 # CDDL HEADER END
  38 #
  39 #
  40 # Fields have a fixed width. Every interval, we fill the "v"
  41 # hash with its corresponding value (v[field]=value) using calculate().
  42 # @hdr is the array of fields that needs to be printed, so we
  43 # just iterate over this array and print the values using our pretty printer.
  44 #
  45
  46
  47 import sys
  48 import time
  49 import getopt
  50 import re
  51 import copy
  52
  53 from decimal import Decimal
  54 from subprocess import Popen, PIPE
  55 from signal import signal, SIGINT
  56
  57 cols = {
  58     # HDR:        [Size, Scale, Description]
  59     "time":       [8, -1, "Time"],
  60     "hits":       [4, 1000, "ARC reads per second"],
  61     "miss":       [4, 1000, "ARC misses per second"],
  62     "read":       [4, 1000, "Total ARC accesses per second"],
  63     "hit%":       [4, 100, "ARC Hit percentage"],
  64     "miss%":      [5, 100, "ARC miss percentage"],
  65     "dhit":       [4, 1000, "Demand Data hits per second"],
  66     "dmis":       [4, 1000, "Demand Data misses per second"],
  67     "dh%":        [3, 100, "Demand Data hit percentage"],
  68     "dm%":        [3, 100, "Demand Data miss percentage"],
  69     "phit":       [4, 1000, "Prefetch hits per second"],
  70     "pmis":       [4, 1000, "Prefetch misses per second"],
  71     "ph%":        [3, 100, "Prefetch hits percentage"],
  72     "pm%":        [3, 100, "Prefetch miss percentage"],
  73     "mhit":       [4, 1000, "Metadata hits per second"],
  74     "mmis":       [4, 1000, "Metadata misses per second"],
  75     "mread":      [4, 1000, "Metadata accesses per second"],
  76     "mh%":        [3, 100, "Metadata hit percentage"],
  77     "mm%":        [3, 100, "Metadata miss percentage"],
  78     "arcsz":      [5, 1024, "ARC Size"],
  79     "c":          [4, 1024, "ARC Target Size"],
  80     "mfu":        [4, 1000, "MFU List hits per second"],
  81     "mru":        [4, 1000, "MRU List hits per second"],
  82     "mfug":       [4, 1000, "MFU Ghost List hits per second"],
  83     "mrug":       [4, 1000, "MRU Ghost List hits per second"],
  84     "eskip":      [5, 1000, "evict_skip per second"],
  85     "mtxmis":     [6, 1000, "mutex_miss per second"],
  86     "rmis":       [4, 1000, "recycle_miss per second"],
  87     "dread":      [5, 1000, "Demand data accesses per second"],
  88     "pread":      [5, 1000, "Prefetch accesses per second"],
  89     "l2hits":     [6, 1000, "L2ARC hits per second"],
  90     "l2miss":     [6, 1000, "L2ARC misses per second"],
  91     "l2read":     [6, 1000, "Total L2ARC accesses per second"],
  92     "l2hit%":     [6, 100, "L2ARC access hit percentage"],
  93     "l2miss%":    [7, 100, "L2ARC access miss percentage"],
  94     "l2size":     [6, 1024, "Size of the L2ARC"],
  95     "l2bytes":    [7, 1024, "bytes read per second from the L2ARC"],
  96 }
  97
  98 v = {}
  99 hdr = ["time", "read", "miss", "miss%", "dmis", "dm%", "pmis", "pm%", "mmis",
 100     "mm%", "arcsz", "c"]
 101 xhdr = ["time", "mfu", "mru", "mfug", "mrug", "eskip", "mtxmis", "rmis",
 102     "dread", "pread", "read"]
 103 sint = 1               # Default interval is 1 second
 104 count = 1              # Default count is 1
 105 hdr_intr = 20          # Print header every 20 lines of output
 106 opfile = None
 107 sep = "  "              # Default separator is 2 spaces
 108 version = "0.4"
 109 l2exist = False
 110 cmd = ("Usage: arcstat [-hvx] [-f fields] [-o file] [-s string] [interval "
 111     "[count]]\n")
 112 cur = {}
 113 d = {}
 114 out = None
 115 kstat = None
 116 float_pobj = re.compile("^[0-9]+(\.[0-9]+)?$")
 117
 118
 119 def detailed_usage():
 120     sys.stderr.write("%s\n" % cmd)
 121     sys.stderr.write("Field definitions are as follows:\n")
 122     for key in cols:
 123         sys.stderr.write("%11s : %s\n" % (key, cols[key][2]))
 124     sys.stderr.write("\n")
 125
 126     sys.exit(1)
 127
 128
 129 def usage():
 130     sys.stderr.write("%s\n" % cmd)
 131     sys.stderr.write("\t -h : Print this help message\n")
 132     sys.stderr.write("\t -v : List all possible field headers and definitions"
 133         "\n")
 134     sys.stderr.write("\t -x : Print extended stats\n")
 135     sys.stderr.write("\t -f : Specify specific fields to print (see -v)\n")
 136     sys.stderr.write("\t -o : Redirect output to the specified file\n")
 137     sys.stderr.write("\t -s : Override default field separator with custom "
 138         "character or string\n")
 139     sys.stderr.write("\nExamples:\n")
 140     sys.stderr.write("\tarcstat -o /tmp/a.log 2 10\n")
 141     sys.stderr.write("\tarcstat -s \",\" -o /tmp/a.log 2 10\n")
 142     sys.stderr.write("\tarcstat -v\n")
 143     sys.stderr.write("\tarcstat -f time,hit%,dh%,ph%,mh% 1\n")
 144     sys.stderr.write("\n")
 145
 146     sys.exit(1)
 147
 148
 149 def kstat_update():
 150     global kstat
 151
 152     p = Popen("/sbin/sysctl -q 'kstat.zfs.misc.arcstats'", stdin=PIPE,
 153         stdout=PIPE, stderr=PIPE, shell=True, close_fds=True)
 154     p.wait()
 155
 156     k = p.communicate()[0].split('\n')
 157     if p.returncode != 0:
 158         sys.exit(1)
 159
 160     if not k:
 161         sys.exit(1)
 162
 163     kstat = {}
 164
 165     for s in k:
 166         if not s:
 167             continue
 168
 169         s = s.strip()
 170
 171         name, value = s.split(':')
 172         name = name.strip()
 173         value = value.strip()
 174
 175         parts = name.split('.')
 176         n = parts.pop()
 177
 178         kstat[n] = Decimal(value)
 179
 180
 181 def snap_stats():
 182     global cur
 183     global kstat
 184
 185     prev = copy.deepcopy(cur)
 186     kstat_update()
 187
 188     cur = kstat
 189     for key in cur:
 190         if re.match(key, "class"):
 191             continue
 192         if key in prev:
 193             d[key] = cur[key] - prev[key]
 194         else:
 195             d[key] = cur[key]
 196
 197
 198 def prettynum(sz, scale, num=0):
 199     suffix = [' ', 'K', 'M', 'G', 'T', 'P', 'E', 'Z']
 200     index = 0
 201     save = 0
 202
 203     # Special case for date field
 204     if scale == -1:
 205         return "%s" % num
 206
 207     # Rounding error, return 0
 208     elif num > 0 and num < 1:
 209         num = 0
 210
 211     while num > scale and index < 5:
 212         save = num
 213         num = num / scale
 214         index += 1
 215
 216     if index == 0:
 217         return "%*d" % (sz, num)
 218
 219     if (save / scale) < 10:
 220         return "%*.1f%s" % (sz - 1, num, suffix[index])
 221     else:
 222         return "%*d%s" % (sz - 1, num, suffix[index])
 223
 224
 225 def print_values():
 226     global hdr
 227     global sep
 228     global v
 229
 230     for col in hdr:
 231         sys.stdout.write("%s%s" % (
 232             prettynum(cols[col][0], cols[col][1], v[col]),
 233             sep
 234             ))
 235     sys.stdout.write("\n")
 236
 237
 238 def print_header():
 239     global hdr
 240     global sep
 241
 242     for col in hdr:
 243         sys.stdout.write("%*s%s" % (cols[col][0], col, sep))
 244     sys.stdout.write("\n")
 245
 246
 247 def init():
 248     global sint
 249     global count
 250     global hdr
 251     global xhdr
 252     global opfile
 253     global sep
 254     global out
 255     global l2exist
 256
 257     desired_cols = None
 258     xflag = False
 259     hflag = False
 260     vflag = False
 261     i = 1
 262
 263     try:
 264         opts, args = getopt.getopt(
 265             sys.argv[1:],
 266             "xo:hvs:f:",
 267             [
 268                 "extended",
 269                 "outfile",
 270                 "help",
 271                 "verbose",
 272                 "seperator",
 273                 "columns"
 274             ]
 275         )
 276
 277     except getopt.error, msg:
 278         sys.stderr.write(msg)
 279         usage()
 280
 281     for opt, arg in opts:
 282         if opt in ('-x', '--extended'):
 283             xflag = True
 284         if opt in ('-o', '--outfile'):
 285             opfile = arg
 286             i += 1
 287         if opt in ('-h', '--help'):
 288             hflag = True
 289         if opt in ('-v', '--verbose'):
 290             vflag = True
 291         if opt in ('-s', '--seperator'):
 292             sep = arg
 293             i += 1
 294         if opt in ('-f', '--columns'):
 295             desired_cols = arg
 296             i += 1
 297         i += 1
 298
 299     argv = sys.argv[i:]
 300     sint = Decimal(argv[0]) if argv else sint
 301     count = int(argv[1]) if len(argv) > 1 else count
 302
 303     if len(argv) > 1:
 304         sint = Decimal(argv[0])
 305         count = int(argv[1])
 306
 307     elif len(argv) > 0:
 308         sint = Decimal(argv[0])
 309         count = 0
 310
 311     if hflag or (xflag and desired_cols):
 312         usage()
 313
 314     if vflag:
 315         detailed_usage()
 316
 317     if xflag:
 318         hdr = xhdr
 319
 320     # check if L2ARC exists
 321     snap_stats()
 322     l2_size = cur.get("l2_size")
 323     if l2_size:
 324         l2exist = True
 325
 326     if desired_cols:
 327         hdr = desired_cols.split(",")
 328
 329         invalid = []
 330         incompat = []
 331         for ele in hdr:
 332             if ele not in cols:
 333                 invalid.append(ele)
 334             elif not l2exist and ele.startswith("l2"):
 335                 sys.stdout.write("No L2ARC Here\n%s\n" % ele)
 336                 incompat.append(ele)
 337
 338         if len(invalid) > 0:
 339             sys.stderr.write("Invalid column definition! -- %s\n" % invalid)
 340             usage()
 341
 342         if len(incompat) > 0:
 343             sys.stderr.write("Incompatible field specified! -- %s\n" % (
 344                 incompat,
 345                 ))
 346             usage()
 347
 348     if opfile:
 349         try:
 350             out = open(opfile, "w")
 351             sys.stdout = out
 352
 353         except:
 354             sys.stderr.write("Cannot open %s for writing\n" % opfile)
 355             sys.exit(1)
 356
 357
 358 def calculate():
 359     global d
 360     global v
 361     global l2exist
 362
 363     v = {}
 364     v["time"] = time.strftime("%H:%M:%S", time.localtime())
 365     v["hits"] = d["hits"] / sint
 366     v["miss"] = d["misses"] / sint
 367     v["read"] = v["hits"] + v["miss"]
 368     v["hit%"] = 100 * v["hits"] / v["read"] if v["read"] > 0 else 0
 369     v["miss%"] = 100 - v["hit%"] if v["read"] > 0 else 0
 370
 371     v["dhit"] = (d["demand_data_hits"] + d["demand_metadata_hits"]) / sint
 372     v["dmis"] = (d["demand_data_misses"] + d["demand_metadata_misses"]) / sint
 373
 374     v["dread"] = v["dhit"] + v["dmis"]
 375     v["dh%"] = 100 * v["dhit"] / v["dread"] if v["dread"] > 0 else 0
 376     v["dm%"] = 100 - v["dh%"] if v["dread"] > 0 else 0
 377
 378     v["phit"] = (d["prefetch_data_hits"] + d["prefetch_metadata_hits"]) / sint
 379     v["pmis"] = (d["prefetch_data_misses"] +
 380         d["prefetch_metadata_misses"]) / sint
 381
 382     v["pread"] = v["phit"] + v["pmis"]
 383     v["ph%"] = 100 * v["phit"] / v["pread"] if v["pread"] > 0 else 0
 384     v["pm%"] = 100 - v["ph%"] if v["pread"] > 0 else 0
 385
 386     v["mhit"] = (d["prefetch_metadata_hits"] +
 387         d["demand_metadata_hits"]) / sint
 388     v["mmis"] = (d["prefetch_metadata_misses"] +
 389         d["demand_metadata_misses"]) / sint
 390
 391     v["mread"] = v["mhit"] + v["mmis"]
 392     v["mh%"] = 100 * v["mhit"] / v["mread"] if v["mread"] > 0 else 0
 393     v["mm%"] = 100 - v["mh%"] if v["mread"] > 0 else 0
 394
 395     v["arcsz"] = cur["size"]
 396     v["c"] = cur["c"]
 397     v["mfu"] = d["mfu_hits"] / sint
 398     v["mru"] = d["mru_hits"] / sint
 399     v["mrug"] = d["mru_ghost_hits"] / sint
 400     v["mfug"] = d["mfu_ghost_hits"] / sint
 401     v["eskip"] = d["evict_skip"] / sint
 402     v["rmis"] = d["recycle_miss"] / sint
 403     v["mtxmis"] = d["mutex_miss"] / sint
 404
 405     if l2exist:
 406         v["l2hits"] = d["l2_hits"] / sint
 407         v["l2miss"] = d["l2_misses"] / sint
 408         v["l2read"] = v["l2hits"] + v["l2miss"]
 409         v["l2hit%"] = 100 * v["l2hits"] / v["l2read"] if v["l2read"] > 0 else 0
 410
 411         v["l2miss%"] = 100 - v["l2hit%"] if v["l2read"] > 0 else 0
 412         v["l2size"] = cur["l2_size"]
 413         v["l2bytes"] = d["l2_read_bytes"] / sint
 414
 415
 416 def sighandler(*args):
 417     sys.exit(0)
 418
 419
 420 def main():
 421     global sint
 422     global count
 423     global hdr_intr
 424
 425     i = 0
 426     count_flag = 0
 427
 428     init()
 429     if count > 0:
 430         count_flag = 1
 431
 432     signal(SIGINT, sighandler)
 433     while True:
 434         if i == 0:
 435             print_header()
 436
 437         snap_stats()
 438         calculate()
 439         print_values()
 440
 441         if count_flag == 1:
 442             if count <= 1:
 443                 break
 444             count -= 1
 445
 446         i = 0 if i == hdr_intr else i + 1
 447         time.sleep(sint)
 448
 449     if out:
 450         out.close()
 451
 452
 453 if __name__ == '__main__':
 454     main()