memory leak on standard requests

[Daniel Kahn Gillmor]

​imported from mantis, dkg wrote:

Hardy Griech reported what used to be bug 2 here about a recurrent memory leak, which appears to still be a problem:

• ​http://lists.outoforder.cc/pipermail/modules/2011-September/000424.html
• ​http://lists.outoforder.cc/pipermail/modules/2012-September/000427.html

The code below makes it possible to reproduce the memory leak directly:

while printf "GET / HTTP/1.1\nHost: %s\n\n" "$(hostname -f)" | gnutls-cli 127.0.1.1 --insecure; do : ; done

This is using packages from debian testing.

[Daniel Kahn Gillmor]

on 2013-03-04 d4sh2007 wrote:

I can not reproduce this bug.

I am using the following shell script to execute requests

#!/bin/bash

while printf "GET / HTTP/1.1\nHost: %s\n\n" "$(hostname -f)" | gnutls-cli dash.za.net; ps aux |grep httpd|awk '{ SUM += $5} END { print SUM/1024/1024 }'; do : ; done

The sum of the Virtual-Memory-Size of all of apache's httpd processes does not appear to increase.

Can anyone clarify this?

[Daniel Kahn Gillmor]

benbe wrote:

Maybe have a look at it with valgrind. Make sure to install the *-dbg packages so you have debugging symbols available (the output is MUCH nicer then ;-))

Haven't tested this.

[Daniel Kahn Gillmor]

d4sh2007 wrote:

Here's some notes that hopefully will shed some light on resolving this issue.

• ​http://foertsch.name/ModPerl-Tricks/Measuring-memory-consumption/index.shtml
• ​http://apache-http-server.18135.n6.nabble.com/Finding-memory-leaks-in-httpd-and-httpd-modules-td4829792.html
• ​http://carbonshaft.blogspot.com/2011/09/using-valgrind-to-find-apache-httpd.html

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• ​http://linux.die.net/man/3/gnutls_global_init

  Note! This function is not thread safe. If two threads call this function simultaneously, they can cause a race between checking the global counter and incrementing it, causing both threads to execute the library initialization code. That would lead to a memory leak. To handle this, your application could invoke this function after aquiring a thread mutex. To ignore the potential memory leak is also an option.
  

• ​Apache Memory Management