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zephyr_mirror: Fix killing duplicate zephyr_mirror processes.

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The refactoring that we did a couple weeks ago to make the zephyr
mirror script restart itself automatically (by splitting it into
zephyr_mirror.py and zephyr_mirror_backend.py) had a poor interaction
with our code for killing old zephyr_mirror processes (to prevent
double-mirroring).  If you manually ran two copies of the outer
mirroring script (zephyr_mirror.py), then the second one would on
startup kill the first one's zephyr_mirror_backend.py children (for
being duplicate zephyr_mirror_backend.py processes that would result
in double-mirroring).  However, importantly, it did not kill the first
mirroring script's zephyr_mirror.py parent process, so the first
mirroring script would then proceed to startup up new children.  The
process then repeats, with the two scripts' roles reversed.

This issue didn't affect the sharded mirroring case, where I had been
doing the testing of the kill code with that refactoring, because we
don't have a version of the outer zephyr_mirror.py loop for that
situation (a consequence of it being hard to restart the threads
properly with the run_parallel API that we're using to spawn all the
children).

(imported from commit d4886ac77312a6b0ebd0d612f6fb084970bf23a2)
This commit is contained in:
Tim Abbott 2012-12-21 11:26:36 -05:00
parent a22f94633b
commit 25bb86d2d0
1 changed files with 14 additions and 13 deletions
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27
bots/zephyr_mirror_backend.py
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@ -831,25 +831,26 @@ or specify the --api-key-file option.""" % (options.api_key_file,)))
add_humbug_subscriptions(True) add_humbug_subscriptions(True)
sys.exit(0) sys.exit(0)
# First check that there are no other bots running # Kill all zephyr_mirror processes other than this one and its parent.
bot_name = "zephyr_mirror_backend.py"
if not options.test_mode: if not options.test_mode:
pgrep_query = bot_name pgrep_query = "/usr/bin/python.*zephyr_mirror"
if options.shard is not None: if options.shard is not None:
pgrep_query = "%s.*--shard=%s" % (bot_name, options.shard) pgrep_query = "%s.*--shard=%s" % (pgrep_query, options.shard)
proc = subprocess.Popen(['pgrep', '-U', os.environ["USER"], "-f", pgrep_query], proc = subprocess.Popen(['pgrep', '-U', os.environ["USER"], "-f", pgrep_query],
stdout=subprocess.PIPE, stdout=subprocess.PIPE,
stderr=subprocess.PIPE) stderr=subprocess.PIPE)
out, _err_unused = proc.communicate() out, _err_unused = proc.communicate()
for pid in out.split(): for pid in map(int, out.split()):
if int(pid.strip()) != os.getpid(): if pid == os.getpid() or pid == os.getppid():
# Another copy of zephyr_mirror.py! Kill it. continue
print "Killing duplicate zephyr_mirror process %s" % (pid,)
try: # Another copy of zephyr_mirror.py! Kill it.
os.kill(int(pid), signal.SIGKILL) print "Killing duplicate zephyr_mirror process %s" % (pid,)
except OSError: try:
# We don't care if the child process no longer exists, so just print the error os.kill(pid, signal.SIGKILL)
traceback.print_exc() except OSError:
# We don't care if the target process no longer exists, so just print the error
traceback.print_exc()
if options.shard is not None and set(options.shard) != set("a"): if options.shard is not None and set(options.shard) != set("a"):
# The shard that is all "a"s is the one that handles personals # The shard that is all "a"s is the one that handles personals