hphp/tools/hhvm-leak-isolator

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3 """
   4   This script can help you isolate memory leaks in HHVM. It will request a heap
   5   dump from HHVM at regular intervals and diff successive dumps to show you
   6   which code paths are allocating memory.
   7
   8   requirements:
   9     * HHVM debug symbols.
  10     * a copy of libjemalloc compiled with `--enable-prof`.
  11       (the script will check your libjemalloc for profiling capabilities
  12       and alert you if they are missing.)
  13     * Google Perf Tools (for diffing heaps).
  14     * Ability to make HTTP or HTTPS requests to the HHVM admin server.
  15
  16   usage: hhvm-leak-isolator [--heap-dir HEAP_DIR] [--check-only]
  17                             [--admin-server URL] [--interval MINS]
  18
  19   optional arguments:
  20     -h, --help           show this help message and exit
  21     --heap-dir HEAP_DIR  Dump heaps to this directory (default: $TMP).
  22     --check-only         Check for heap profiling capabilities and exit.
  23     --admin-server URL   HHVM admin server URL (default: http://localhost:9002)
  24     --interval MINS      Time to sleep between heap dumps (default: 5).
  25
  26   Author: Ori Livneh
  27
  28 """
  29 from __future__ import print_function
  30
  31 import argparse
  32 import ctypes
  33 import ctypes.util
  34 import distutils.spawn
  35 import os
  36 import subprocess
  37 import sys
  38 import tempfile
  39 import textwrap
  40 import time
  41
  42 try:
  43     from urllib import urlencode
  44     from urllib2 import urlopen
  45     from urlparse import urljoin
  46 except ImportError:
  47     from urllib.parse import urlencode, urljoin
  48     from urllib.request import urlopen
  49
  50
  51 temp_dir = tempfile.gettempdir()
  52 ap = argparse.ArgumentParser(
  53     description=textwrap.dedent(__doc__.split('usage')[0]),
  54     formatter_class=argparse.RawDescriptionHelpFormatter)
  55 ap.add_argument('--heap-dir', default=temp_dir, type=os.path.abspath,
  56                 help='Dump heaps to this directory (default: %s).' % temp_dir)
  57 ap.add_argument('--check-only', action='store_true', default=False,
  58                 help='Check for heap profiling capabilities and exit.')
  59 ap.add_argument('--admin-server', default='http://localhost:9002',
  60                 help='HHVM admin server URL (default: http://localhost:9002)',
  61                 metavar='URL')
  62 ap.add_argument('--interval', default=5, type=int, metavar='MINS',
  63                 help='Time to sleep between heap dumps (default: 5).')
  64 args = ap.parse_args()
  65
  66
  67 def get_jemalloc_can_profile():
  68     """Check if libjemalloc was built with `--enable-prof` and thus
  69     has heap profiling capabilities."""
  70     jemalloc_so = ctypes.util.find_library('jemalloc')
  71     if jemalloc_so is None:
  72         raise EnvironmentError('Could not find libjemalloc!')
  73     jemalloc = ctypes.CDLL(jemalloc_so, use_errno=True)
  74
  75     has_prof = ctypes.c_bool(False)
  76     has_prof_len = ctypes.c_size_t(ctypes.sizeof(has_prof))
  77     rv = jemalloc.mallctl(b'config.prof', ctypes.byref(has_prof),
  78                           ctypes.byref(has_prof_len), None, None)
  79     if rv != 0:
  80         err = ctypes.get_errno()
  81         raise OSError(err, os.strerror(err))
  82
  83     return bool(has_prof)
  84
  85
  86 def hhvm_admin_do(endpoint, **query_params):
  87     url = urljoin(args.admin_server, endpoint)
  88     if query_params:
  89         url += '?' + urlencode(query_params)
  90     req = urlopen(url)
  91     return req.read().decode('utf-8')
  92
  93
  94 if get_jemalloc_can_profile():
  95     print('OK: jemalloc built with `--enable-prof`.')
  96 else:
  97     print('NOT OK: your copy of libjemalloc was not built with `--enable-prof`'
  98           ' and thus has no heap profiling capabilities.', file=sys.stderr)
  99     sys.exit(1)
 100
 101 try:
 102     stats = hhvm_admin_do('jemalloc-stats-print')
 103 except EnvironmentError:
 104     print('NOT OK: Could not connect to an HHVM admin server at %s.\n'
 105           ' Use `--admin-server` to specify an alternate URL.'
 106           % args.admin_server, file=sys.stderr)
 107     sys.exit(1)
 108
 109 if 'opt.prof: true' in stats:
 110     print('OK: jemalloc heap profiling is active (prof: true).')
 111 else:
 112     print('NOT OK: jemalloc heap profiling is off.'
 113           ' Run `sudo ln -sf prof:true /etc/malloc.conf` and restart HHVM.',
 114           file=sys.stderr)
 115     sys.exit(1)
 116
 117 hhvm_path = distutils.spawn.find_executable('hhvm')
 118 pprof_path = (distutils.spawn.find_executable('google-pprof') or
 119               distutils.spawn.find_executable('pprof'))
 120 if pprof_path:
 121     print('OK: pprof is %s.' % pprof_path)
 122 else:
 123     print('WARN: Could not find `pprof` or `google-pprof` in $PATH. '
 124           'pprof is required for diffing heap dumps.\n'
 125           'Install the `google-perftools` package or see '
 126           'https://code.google.com/p/gperftools/.', file=sys.stderr)
 127
 128 if args.check_only:
 129     sys.exit(0)
 130
 131
 132 hhvm_admin_do('jemalloc-prof-activate')
 133 if 'ACTIVE' not in hhvm_admin_do('jemalloc-prof-status'):
 134     print('NOT OK: failed to activate jemalloc profiling.', file=sys.stderr)
 135     sys.exit(1)
 136
 137 print('I will write heap files to %s every %d minute(s).' %
 138       (os.path.join(args.heap_dir, 'hhvm-heap.*'), args.interval))
 139
 140 heap_files = []
 141 while 1:
 142     heap_file = os.path.join(args.heap_dir, 'hhvm-heap.%d' % time.time())
 143     heap_files.append(heap_file)
 144     hhvm_admin_do('jemalloc-prof-dump', file=heap_file)
 145     print('Wrote %s.' % heap_file)
 146     if pprof_path and len(heap_files) > 1:
 147         base, heap = heap_files[-2:]
 148         cmd = (pprof_path, hhvm_path, '--show_bytes', '--text',
 149                '--base=%s' % base, heap)
 150         out = subprocess.check_output(cmd, stderr=open(os.devnull, 'w'))
 151         out = out.decode('utf-8', errors='ignore')
 152         if out.strip():
 153             print('-' * 80, '\n', out, '\n', '-' * 80)
 154         else:
 155             print('-- no diff --')
 156     print('Sleeping for %d minute(s).' % args.interval)
 157     time.sleep(args.interval * 60)