commit f6a0a8e899d883869f0ffe19db019f87a076caa7 Author: Damian Johnson atagar@torproject.org Date: Sun Oct 12 11:41:03 2014 -0700

Forking mail subprocess before fetching descriptor data

Nope, attempt to garbage collect the descriptors didn't do the trick. We're still triggering OOM errors. Plan 'b' from...

https://stackoverflow.com/questions/1367373/python-subprocess-popen-oserror-...

... is to fork our process before gobbling up a lot of memory. I don't like this - there should be a way of subprocess without doubling memory usage. Fixing perdulce's overcommit policy would also be a preferable solution.

Oh well. Hopefully this does the trick so I can stop looking at it. --- consensus_health_checker.py | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/consensus_health_checker.py b/consensus_health_checker.py index a86855d..f9dc10e 100755 --- a/consensus_health_checker.py +++ b/consensus_health_checker.py @@ -7,7 +7,7 @@ Performs a variety of checks against the present votes and consensus. """

import datetime -import gc +import subprocess import time import traceback

@@ -190,6 +190,19 @@ def directory_authorities(): def main(): start_time = time.time()

+ if not TEST_RUN: + # Spawning a shell to run mail. We're doing this early because + # subprocess.Popen() calls fork which doubles the memory usage of our + # process. Hence we risk an OOM if this is done after loading gobs of + # descriptor data into memory. + + mail_process = subprocess.Popen( + ['mail', '-E', '-s', EMAIL_SUBJECT, util.TO_ADDRESS], + stdin = subprocess.PIPE, + stdout = subprocess.PIPE, + stderr = subprocess.PIPE, + ) + # loads configuration data

config = stem.util.conf.get_config("consensus_health") @@ -220,19 +233,14 @@ def main(): for issue in issues: rate_limit_notice(issue)

- # Reclaim memory of the consensus documents. This is ebecause sending an - # email forks our process, doubling memory usage. This can easily be a - # trigger of an OOM if we're still gobbling tons of memory for the - # descriptor content. - - del consensuses - del votes - gc.collect() - if TEST_RUN: print '\n'.join(map(str, issues)) else: - util.send(EMAIL_SUBJECT, body_text = '\n'.join(map(str, issues))) + stdout, stderr = mail_process.communicate('\n'.join(map(str, issues))) + exit_code = mail_process.poll() + + if exit_code != 0: + raise ValueError("Unable to send email: %s" % stderr.strip())

# notification for #tor-bots