cmd/arcstat/arcstat.py

   1 #!/usr/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 signal import signal, SIGINT, SIGWINCH, SIG_DFL
  55
  56 cols = {
  57     # HDR:        [Size, Scale, Description]
  58     "time":       [8, -1, "Time"],
  59     "hits":       [4, 1000, "ARC reads per second"],
  60     "miss":       [4, 1000, "ARC misses per second"],
  61     "read":       [4, 1000, "Total ARC accesses per second"],
  62     "hit%":       [4, 100, "ARC Hit percentage"],
  63     "miss%":      [5, 100, "ARC miss percentage"],
  64     "dhit":       [4, 1000, "Demand hits per second"],
  65     "dmis":       [4, 1000, "Demand misses per second"],
  66     "dh%":        [3, 100, "Demand hit percentage"],
  67     "dm%":        [3, 100, "Demand miss percentage"],
  68     "phit":       [4, 1000, "Prefetch hits per second"],
  69     "pmis":       [4, 1000, "Prefetch misses per second"],
  70     "ph%":        [3, 100, "Prefetch hits percentage"],
  71     "pm%":        [3, 100, "Prefetch miss percentage"],
  72     "mhit":       [4, 1000, "Metadata hits per second"],
  73     "mmis":       [4, 1000, "Metadata misses per second"],
  74     "mread":      [4, 1000, "Metadata accesses per second"],
  75     "mh%":        [3, 100, "Metadata hit percentage"],
  76     "mm%":        [3, 100, "Metadata miss percentage"],
  77     "arcsz":      [5, 1024, "ARC Size"],
  78     "c":          [4, 1024, "ARC Target Size"],
  79     "mfu":        [4, 1000, "MFU List hits per second"],
  80     "mru":        [4, 1000, "MRU List hits per second"],
  81     "mfug":       [4, 1000, "MFU Ghost List hits per second"],
  82     "mrug":       [4, 1000, "MRU Ghost List hits per second"],
  83     "eskip":      [5, 1000, "evict_skip per second"],
  84     "mtxmis":     [6, 1000, "mutex_miss per second"],
  85     "dread":      [5, 1000, "Demand accesses per second"],
  86     "pread":      [5, 1000, "Prefetch accesses per second"],
  87     "l2hits":     [6, 1000, "L2ARC hits per second"],
  88     "l2miss":     [6, 1000, "L2ARC misses per second"],
  89     "l2read":     [6, 1000, "Total L2ARC accesses per second"],
  90     "l2hit%":     [6, 100, "L2ARC access hit percentage"],
  91     "l2miss%":    [7, 100, "L2ARC access miss percentage"],
  92     "l2asize":    [7, 1024, "Actual (compressed) size of the L2ARC"],
  93     "l2size":     [6, 1024, "Size of the L2ARC"],
  94     "l2bytes":    [7, 1024, "bytes read per second from the L2ARC"],
  95 }
  96
  97 v = {}
  98 hdr = ["time", "read", "miss", "miss%", "dmis", "dm%", "pmis", "pm%", "mmis",
  99        "mm%", "arcsz", "c"]
 100 xhdr = ["time", "mfu", "mru", "mfug", "mrug", "eskip", "mtxmis", "dread",
 101         "pread", "read"]
 102 sint = 1               # Default interval is 1 second
 103 count = 1              # Default count is 1
 104 hdr_intr = 20          # Print header every 20 lines of output
 105 opfile = None
 106 sep = "  "              # Default separator is 2 spaces
 107 version = "0.4"
 108 l2exist = False
 109 cmd = ("Usage: arcstat.py [-hvx] [-f fields] [-o file] [-s string] [interval "
 110        "[count]]\n")
 111 cur = {}
 112 d = {}
 113 out = None
 114 kstat = None
 115 float_pobj = re.compile("^[0-9]+(\.[0-9]+)?$")
 116
 117
 118 def detailed_usage():
 119     sys.stderr.write("%s\n" % cmd)
 120     sys.stderr.write("Field definitions are as follows:\n")
 121     for key in cols:
 122         sys.stderr.write("%11s : %s\n" % (key, cols[key][2]))
 123     sys.stderr.write("\n")
 124
 125     sys.exit(0)
 126
 127
 128 def usage():
 129     sys.stderr.write("%s\n" % cmd)
 130     sys.stderr.write("\t -h : Print this help message\n")
 131     sys.stderr.write("\t -v : List all possible field headers and definitions"
 132                      "\n")
 133     sys.stderr.write("\t -x : Print extended stats\n")
 134     sys.stderr.write("\t -f : Specify specific fields to print (see -v)\n")
 135     sys.stderr.write("\t -o : Redirect output to the specified file\n")
 136     sys.stderr.write("\t -s : Override default field separator with custom "
 137                      "character or string\n")
 138     sys.stderr.write("\nExamples:\n")
 139     sys.stderr.write("\tarcstat.py -o /tmp/a.log 2 10\n")
 140     sys.stderr.write("\tarcstat.py -s \",\" -o /tmp/a.log 2 10\n")
 141     sys.stderr.write("\tarcstat.py -v\n")
 142     sys.stderr.write("\tarcstat.py -f time,hit%,dh%,ph%,mh% 1\n")
 143     sys.stderr.write("\n")
 144
 145     sys.exit(1)
 146
 147
 148 def kstat_update():
 149     global kstat
 150
 151     k = [line.strip() for line in open('/proc/spl/kstat/zfs/arcstats')]
 152
 153     if not k:
 154         sys.exit(1)
 155
 156     del k[0:2]
 157     kstat = {}
 158
 159     for s in k:
 160         if not s:
 161             continue
 162
 163         name, unused, value = s.split()
 164         kstat[name] = Decimal(value)
 165
 166
 167 def snap_stats():
 168     global cur
 169     global kstat
 170
 171     prev = copy.deepcopy(cur)
 172     kstat_update()
 173
 174     cur = kstat
 175     for key in cur:
 176         if re.match(key, "class"):
 177             continue
 178         if key in prev:
 179             d[key] = cur[key] - prev[key]
 180         else:
 181             d[key] = cur[key]
 182
 183
 184 def prettynum(sz, scale, num=0):
 185     suffix = [' ', 'K', 'M', 'G', 'T', 'P', 'E', 'Z']
 186     index = 0
 187     save = 0
 188
 189     # Special case for date field
 190     if scale == -1:
 191         return "%s" % num
 192
 193     # Rounding error, return 0
 194     elif 0 < num < 1:
 195         num = 0
 196
 197     while num > scale and index < 5:
 198         save = num
 199         num = num / scale
 200         index += 1
 201
 202     if index == 0:
 203         return "%*d" % (sz, num)
 204
 205     if (save / scale) < 10:
 206         return "%*.1f%s" % (sz - 1, num, suffix[index])
 207     else:
 208         return "%*d%s" % (sz - 1, num, suffix[index])
 209
 210
 211 def print_values():
 212     global hdr
 213     global sep
 214     global v
 215
 216     for col in hdr:
 217         sys.stdout.write("%s%s" % (
 218             prettynum(cols[col][0], cols[col][1], v[col]),
 219             sep
 220         ))
 221     sys.stdout.write("\n")
 222     sys.stdout.flush()
 223
 224
 225 def print_header():
 226     global hdr
 227     global sep
 228
 229     for col in hdr:
 230         sys.stdout.write("%*s%s" % (cols[col][0], col, sep))
 231     sys.stdout.write("\n")
 232
 233
 234 def get_terminal_lines():
 235     try:
 236         import fcntl
 237         import termios
 238         import struct
 239         data = fcntl.ioctl(sys.stdout.fileno(), termios.TIOCGWINSZ, '1234')
 240         sz = struct.unpack('hh', data)
 241         return sz[0]
 242     except Exception:
 243         pass
 244
 245
 246 def update_hdr_intr():
 247     global hdr_intr
 248
 249     lines = get_terminal_lines()
 250     if lines and lines > 3:
 251         hdr_intr = lines - 3
 252
 253
 254 def resize_handler(signum, frame):
 255     update_hdr_intr()
 256
 257
 258 def init():
 259     global sint
 260     global count
 261     global hdr
 262     global xhdr
 263     global opfile
 264     global sep
 265     global out
 266     global l2exist
 267
 268     desired_cols = None
 269     xflag = False
 270     hflag = False
 271     vflag = False
 272     i = 1
 273
 274     try:
 275         opts, args = getopt.getopt(
 276             sys.argv[1:],
 277             "xo:hvs:f:",
 278             [
 279                 "extended",
 280                 "outfile",
 281                 "help",
 282                 "verbose",
 283                 "separator",
 284                 "columns"
 285             ]
 286         )
 287     except getopt.error as msg:
 288         sys.stderr.write(msg)
 289         usage()
 290         opts = None
 291
 292     for opt, arg in opts:
 293         if opt in ('-x', '--extended'):
 294             xflag = True
 295         if opt in ('-o', '--outfile'):
 296             opfile = arg
 297             i += 1
 298         if opt in ('-h', '--help'):
 299             hflag = True
 300         if opt in ('-v', '--verbose'):
 301             vflag = True
 302         if opt in ('-s', '--separator'):
 303             sep = arg
 304             i += 1
 305         if opt in ('-f', '--columns'):
 306             desired_cols = arg
 307             i += 1
 308         i += 1
 309
 310     argv = sys.argv[i:]
 311     sint = Decimal(argv[0]) if argv else sint
 312     count = int(argv[1]) if len(argv) > 1 else count
 313
 314     if len(argv) > 1:
 315         sint = Decimal(argv[0])
 316         count = int(argv[1])
 317
 318     elif len(argv) > 0:
 319         sint = Decimal(argv[0])
 320         count = 0
 321
 322     if hflag or (xflag and desired_cols):
 323         usage()
 324
 325     if vflag:
 326         detailed_usage()
 327
 328     if xflag:
 329         hdr = xhdr
 330
 331     update_hdr_intr()
 332
 333     # check if L2ARC exists
 334     snap_stats()
 335     l2_size = cur.get("l2_size")
 336     if l2_size:
 337         l2exist = True
 338
 339     if desired_cols:
 340         hdr = desired_cols.split(",")
 341
 342         invalid = []
 343         incompat = []
 344         for ele in hdr:
 345             if ele not in cols:
 346                 invalid.append(ele)
 347             elif not l2exist and ele.startswith("l2"):
 348                 sys.stdout.write("No L2ARC Here\n%s\n" % ele)
 349                 incompat.append(ele)
 350
 351         if len(invalid) > 0:
 352             sys.stderr.write("Invalid column definition! -- %s\n" % invalid)
 353             usage()
 354
 355         if len(incompat) > 0:
 356             sys.stderr.write("Incompatible field specified! -- %s\n" %
 357                              incompat)
 358             usage()
 359
 360     if opfile:
 361         try:
 362             out = open(opfile, "w")
 363             sys.stdout = out
 364
 365         except IOError:
 366             sys.stderr.write("Cannot open %s for writing\n" % opfile)
 367             sys.exit(1)
 368
 369
 370 def calculate():
 371     global d
 372     global v
 373     global l2exist
 374
 375     v = dict()
 376     v["time"] = time.strftime("%H:%M:%S", time.localtime())
 377     v["hits"] = d["hits"] / sint
 378     v["miss"] = d["misses"] / sint
 379     v["read"] = v["hits"] + v["miss"]
 380     v["hit%"] = 100 * v["hits"] / v["read"] if v["read"] > 0 else 0
 381     v["miss%"] = 100 - v["hit%"] if v["read"] > 0 else 0
 382
 383     v["dhit"] = (d["demand_data_hits"] + d["demand_metadata_hits"]) / sint
 384     v["dmis"] = (d["demand_data_misses"] + d["demand_metadata_misses"]) / sint
 385
 386     v["dread"] = v["dhit"] + v["dmis"]
 387     v["dh%"] = 100 * v["dhit"] / v["dread"] if v["dread"] > 0 else 0
 388     v["dm%"] = 100 - v["dh%"] if v["dread"] > 0 else 0
 389
 390     v["phit"] = (d["prefetch_data_hits"] + d["prefetch_metadata_hits"]) / sint
 391     v["pmis"] = (d["prefetch_data_misses"] +
 392                  d["prefetch_metadata_misses"]) / sint
 393
 394     v["pread"] = v["phit"] + v["pmis"]
 395     v["ph%"] = 100 * v["phit"] / v["pread"] if v["pread"] > 0 else 0
 396     v["pm%"] = 100 - v["ph%"] if v["pread"] > 0 else 0
 397
 398     v["mhit"] = (d["prefetch_metadata_hits"] +
 399                  d["demand_metadata_hits"]) / sint
 400     v["mmis"] = (d["prefetch_metadata_misses"] +
 401                  d["demand_metadata_misses"]) / sint
 402
 403     v["mread"] = v["mhit"] + v["mmis"]
 404     v["mh%"] = 100 * v["mhit"] / v["mread"] if v["mread"] > 0 else 0
 405     v["mm%"] = 100 - v["mh%"] if v["mread"] > 0 else 0
 406
 407     v["arcsz"] = cur["size"]
 408     v["c"] = cur["c"]
 409     v["mfu"] = d["mfu_hits"] / sint
 410     v["mru"] = d["mru_hits"] / sint
 411     v["mrug"] = d["mru_ghost_hits"] / sint
 412     v["mfug"] = d["mfu_ghost_hits"] / sint
 413     v["eskip"] = d["evict_skip"] / sint
 414     v["mtxmis"] = d["mutex_miss"] / sint
 415
 416     if l2exist:
 417         v["l2hits"] = d["l2_hits"] / sint
 418         v["l2miss"] = d["l2_misses"] / sint
 419         v["l2read"] = v["l2hits"] + v["l2miss"]
 420         v["l2hit%"] = 100 * v["l2hits"] / v["l2read"] if v["l2read"] > 0 else 0
 421
 422         v["l2miss%"] = 100 - v["l2hit%"] if v["l2read"] > 0 else 0
 423         v["l2asize"] = cur["l2_asize"]
 424         v["l2size"] = cur["l2_size"]
 425         v["l2bytes"] = d["l2_read_bytes"] / sint
 426
 427
 428 def main():
 429     global sint
 430     global count
 431     global hdr_intr
 432
 433     i = 0
 434     count_flag = 0
 435
 436     init()
 437     if count > 0:
 438         count_flag = 1
 439
 440     signal(SIGINT, SIG_DFL)
 441     signal(SIGWINCH, resize_handler)
 442     while True:
 443         if i == 0:
 444             print_header()
 445
 446         snap_stats()
 447         calculate()
 448         print_values()
 449
 450         if count_flag == 1:
 451             if count <= 1:
 452                 break
 453             count -= 1
 454
 455         i = 0 if i >= hdr_intr else i + 1
 456         time.sleep(sint)
 457
 458     if out:
 459         out.close()
 460
 461
 462 if __name__ == '__main__':
 463     main()