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":      [5, 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     "grow":       [4, 1000, "ARC Grow disabled"],
  96     "need":       [4, 1024, "ARC Reclaim need"],
  97     "free":       [4, 1024, "ARC Free memory"],
  98 }
  99
 100 v = {}
 101 hdr = ["time", "read", "miss", "miss%", "dmis", "dm%", "pmis", "pm%", "mmis",
 102        "mm%", "arcsz", "c"]
 103 xhdr = ["time", "mfu", "mru", "mfug", "mrug", "eskip", "mtxmis", "dread",
 104         "pread", "read"]
 105 sint = 1               # Default interval is 1 second
 106 count = 1              # Default count is 1
 107 hdr_intr = 20          # Print header every 20 lines of output
 108 opfile = None
 109 sep = "  "              # Default separator is 2 spaces
 110 version = "0.4"
 111 l2exist = False
 112 cmd = ("Usage: arcstat.py [-hvx] [-f fields] [-o file] [-s string] [interval "
 113        "[count]]\n")
 114 cur = {}
 115 d = {}
 116 out = None
 117 kstat = None
 118
 119
 120 def detailed_usage():
 121     sys.stderr.write("%s\n" % cmd)
 122     sys.stderr.write("Field definitions are as follows:\n")
 123     for key in cols:
 124         sys.stderr.write("%11s : %s\n" % (key, cols[key][2]))
 125     sys.stderr.write("\n")
 126
 127     sys.exit(0)
 128
 129
 130 def usage():
 131     sys.stderr.write("%s\n" % cmd)
 132     sys.stderr.write("\t -h : Print this help message\n")
 133     sys.stderr.write("\t -v : List all possible field headers and definitions"
 134                      "\n")
 135     sys.stderr.write("\t -x : Print extended stats\n")
 136     sys.stderr.write("\t -f : Specify specific fields to print (see -v)\n")
 137     sys.stderr.write("\t -o : Redirect output to the specified file\n")
 138     sys.stderr.write("\t -s : Override default field separator with custom "
 139                      "character or string\n")
 140     sys.stderr.write("\nExamples:\n")
 141     sys.stderr.write("\tarcstat.py -o /tmp/a.log 2 10\n")
 142     sys.stderr.write("\tarcstat.py -s \",\" -o /tmp/a.log 2 10\n")
 143     sys.stderr.write("\tarcstat.py -v\n")
 144     sys.stderr.write("\tarcstat.py -f time,hit%,dh%,ph%,mh% 1\n")
 145     sys.stderr.write("\n")
 146
 147     sys.exit(1)
 148
 149
 150 def kstat_update():
 151     global kstat
 152
 153     k = [line.strip() for line in open('/proc/spl/kstat/zfs/arcstats')]
 154
 155     if not k:
 156         sys.exit(1)
 157
 158     del k[0:2]
 159     kstat = {}
 160
 161     for s in k:
 162         if not s:
 163             continue
 164
 165         name, unused, value = s.split()
 166         kstat[name] = Decimal(value)
 167
 168
 169 def snap_stats():
 170     global cur
 171     global kstat
 172
 173     prev = copy.deepcopy(cur)
 174     kstat_update()
 175
 176     cur = kstat
 177     for key in cur:
 178         if re.match(key, "class"):
 179             continue
 180         if key in prev:
 181             d[key] = cur[key] - prev[key]
 182         else:
 183             d[key] = cur[key]
 184
 185
 186 def prettynum(sz, scale, num=0):
 187     suffix = [' ', 'K', 'M', 'G', 'T', 'P', 'E', 'Z']
 188     index = 0
 189     save = 0
 190
 191     # Special case for date field
 192     if scale == -1:
 193         return "%s" % num
 194
 195     # Rounding error, return 0
 196     elif 0 < num < 1:
 197         num = 0
 198
 199     while num > scale and index < 5:
 200         save = num
 201         num = num / scale
 202         index += 1
 203
 204     if index == 0:
 205         return "%*d" % (sz, num)
 206
 207     if (save / scale) < 10:
 208         return "%*.1f%s" % (sz - 1, num, suffix[index])
 209     else:
 210         return "%*d%s" % (sz - 1, num, suffix[index])
 211
 212
 213 def print_values():
 214     global hdr
 215     global sep
 216     global v
 217
 218     for col in hdr:
 219         sys.stdout.write("%s%s" % (
 220             prettynum(cols[col][0], cols[col][1], v[col]),
 221             sep
 222         ))
 223     sys.stdout.write("\n")
 224     sys.stdout.flush()
 225
 226
 227 def print_header():
 228     global hdr
 229     global sep
 230
 231     for col in hdr:
 232         sys.stdout.write("%*s%s" % (cols[col][0], col, sep))
 233     sys.stdout.write("\n")
 234
 235
 236 def get_terminal_lines():
 237     try:
 238         import fcntl
 239         import termios
 240         import struct
 241         data = fcntl.ioctl(sys.stdout.fileno(), termios.TIOCGWINSZ, '1234')
 242         sz = struct.unpack('hh', data)
 243         return sz[0]
 244     except Exception:
 245         pass
 246
 247
 248 def update_hdr_intr():
 249     global hdr_intr
 250
 251     lines = get_terminal_lines()
 252     if lines and lines > 3:
 253         hdr_intr = lines - 3
 254
 255
 256 def resize_handler(signum, frame):
 257     update_hdr_intr()
 258
 259
 260 def init():
 261     global sint
 262     global count
 263     global hdr
 264     global xhdr
 265     global opfile
 266     global sep
 267     global out
 268     global l2exist
 269
 270     desired_cols = None
 271     xflag = False
 272     hflag = False
 273     vflag = False
 274     i = 1
 275
 276     try:
 277         opts, args = getopt.getopt(
 278             sys.argv[1:],
 279             "xo:hvs:f:",
 280             [
 281                 "extended",
 282                 "outfile",
 283                 "help",
 284                 "verbose",
 285                 "separator",
 286                 "columns"
 287             ]
 288         )
 289     except getopt.error as msg:
 290         sys.stderr.write("Error: %s\n" % str(msg))
 291         usage()
 292         opts = None
 293
 294     for opt, arg in opts:
 295         if opt in ('-x', '--extended'):
 296             xflag = True
 297         if opt in ('-o', '--outfile'):
 298             opfile = arg
 299             i += 1
 300         if opt in ('-h', '--help'):
 301             hflag = True
 302         if opt in ('-v', '--verbose'):
 303             vflag = True
 304         if opt in ('-s', '--separator'):
 305             sep = arg
 306             i += 1
 307         if opt in ('-f', '--columns'):
 308             desired_cols = arg
 309             i += 1
 310         i += 1
 311
 312     argv = sys.argv[i:]
 313     sint = Decimal(argv[0]) if argv else sint
 314     count = int(argv[1]) if len(argv) > 1 else count
 315
 316     if len(argv) > 1:
 317         sint = Decimal(argv[0])
 318         count = int(argv[1])
 319
 320     elif len(argv) > 0:
 321         sint = Decimal(argv[0])
 322         count = 0
 323
 324     if hflag or (xflag and desired_cols):
 325         usage()
 326
 327     if vflag:
 328         detailed_usage()
 329
 330     if xflag:
 331         hdr = xhdr
 332
 333     update_hdr_intr()
 334
 335     # check if L2ARC exists
 336     snap_stats()
 337     l2_size = cur.get("l2_size")
 338     if l2_size:
 339         l2exist = True
 340
 341     if desired_cols:
 342         hdr = desired_cols.split(",")
 343
 344         invalid = []
 345         incompat = []
 346         for ele in hdr:
 347             if ele not in cols:
 348                 invalid.append(ele)
 349             elif not l2exist and ele.startswith("l2"):
 350                 sys.stdout.write("No L2ARC Here\n%s\n" % ele)
 351                 incompat.append(ele)
 352
 353         if len(invalid) > 0:
 354             sys.stderr.write("Invalid column definition! -- %s\n" % invalid)
 355             usage()
 356
 357         if len(incompat) > 0:
 358             sys.stderr.write("Incompatible field specified! -- %s\n" %
 359                              incompat)
 360             usage()
 361
 362     if opfile:
 363         try:
 364             out = open(opfile, "w")
 365             sys.stdout = out
 366
 367         except IOError:
 368             sys.stderr.write("Cannot open %s for writing\n" % opfile)
 369             sys.exit(1)
 370
 371
 372 def calculate():
 373     global d
 374     global v
 375     global l2exist
 376
 377     v = dict()
 378     v["time"] = time.strftime("%H:%M:%S", time.localtime())
 379     v["hits"] = d["hits"] / sint
 380     v["miss"] = d["misses"] / sint
 381     v["read"] = v["hits"] + v["miss"]
 382     v["hit%"] = 100 * v["hits"] / v["read"] if v["read"] > 0 else 0
 383     v["miss%"] = 100 - v["hit%"] if v["read"] > 0 else 0
 384
 385     v["dhit"] = (d["demand_data_hits"] + d["demand_metadata_hits"]) / sint
 386     v["dmis"] = (d["demand_data_misses"] + d["demand_metadata_misses"]) / sint
 387
 388     v["dread"] = v["dhit"] + v["dmis"]
 389     v["dh%"] = 100 * v["dhit"] / v["dread"] if v["dread"] > 0 else 0
 390     v["dm%"] = 100 - v["dh%"] if v["dread"] > 0 else 0
 391
 392     v["phit"] = (d["prefetch_data_hits"] + d["prefetch_metadata_hits"]) / sint
 393     v["pmis"] = (d["prefetch_data_misses"] +
 394                  d["prefetch_metadata_misses"]) / sint
 395
 396     v["pread"] = v["phit"] + v["pmis"]
 397     v["ph%"] = 100 * v["phit"] / v["pread"] if v["pread"] > 0 else 0
 398     v["pm%"] = 100 - v["ph%"] if v["pread"] > 0 else 0
 399
 400     v["mhit"] = (d["prefetch_metadata_hits"] +
 401                  d["demand_metadata_hits"]) / sint
 402     v["mmis"] = (d["prefetch_metadata_misses"] +
 403                  d["demand_metadata_misses"]) / sint
 404
 405     v["mread"] = v["mhit"] + v["mmis"]
 406     v["mh%"] = 100 * v["mhit"] / v["mread"] if v["mread"] > 0 else 0
 407     v["mm%"] = 100 - v["mh%"] if v["mread"] > 0 else 0
 408
 409     v["arcsz"] = cur["size"]
 410     v["c"] = cur["c"]
 411     v["mfu"] = d["mfu_hits"] / sint
 412     v["mru"] = d["mru_hits"] / sint
 413     v["mrug"] = d["mru_ghost_hits"] / sint
 414     v["mfug"] = d["mfu_ghost_hits"] / sint
 415     v["eskip"] = d["evict_skip"] / sint
 416     v["mtxmis"] = d["mutex_miss"] / sint
 417
 418     if l2exist:
 419         v["l2hits"] = d["l2_hits"] / sint
 420         v["l2miss"] = d["l2_misses"] / sint
 421         v["l2read"] = v["l2hits"] + v["l2miss"]
 422         v["l2hit%"] = 100 * v["l2hits"] / v["l2read"] if v["l2read"] > 0 else 0
 423
 424         v["l2miss%"] = 100 - v["l2hit%"] if v["l2read"] > 0 else 0
 425         v["l2asize"] = cur["l2_asize"]
 426         v["l2size"] = cur["l2_size"]
 427         v["l2bytes"] = d["l2_read_bytes"] / sint
 428
 429     v["grow"] = 0 if cur["arc_no_grow"] else 1
 430     v["need"] = cur["arc_need_free"]
 431     v["free"] = cur["arc_sys_free"]
 432
 433
 434 def main():
 435     global sint
 436     global count
 437     global hdr_intr
 438
 439     i = 0
 440     count_flag = 0
 441
 442     init()
 443     if count > 0:
 444         count_flag = 1
 445
 446     signal(SIGINT, SIG_DFL)
 447     signal(SIGWINCH, resize_handler)
 448     while True:
 449         if i == 0:
 450             print_header()
 451
 452         snap_stats()
 453         calculate()
 454         print_values()
 455
 456         if count_flag == 1:
 457             if count <= 1:
 458                 break
 459             count -= 1
 460
 461         i = 0 if i >= hdr_intr else i + 1
 462         time.sleep(sint)
 463
 464     if out:
 465         out.close()
 466
 467
 468 if __name__ == '__main__':
 469     main()