This bug is created as a clone of upstream ticket:
https://fedorahosted.org/389/ticket/47743

I've been running some load tests against version 389-ds-base-1.2.11.15-31.el6_5.x86_64 on Centos 6.5. When looking at the vmsize of the ns-slapd process it appears to grow, rather than reaching a plateau. After some modifications to the load test it appears that the memory usage is flat if we remove the portion that performs the proxied authentication control.

I've created a simplified version of the data that exhibits the problem. This backup ldif is attached to the case. It consists of 3 users and 2 acis.

The load is the following pseudocode:
create a simple connection, binding as uid=AUser,o=Test.com
In 30 threads, repeat 1000 times each (i.e. 30000 total searches):
    using this single connection, proxy as uid=PUser,o=Test.com, and search for uid=SUser

In the end, the access log would look something like:
[13/Mar/2014:16:32:57 +0000] conn=5 op=29999 SRCH base="o=test.com" scope=2 filter="(uid=SUser)" attrs=ALL authzid="uid=puser,o=test.com"
[13/Mar/2014:16:32:57 +0000] conn=5 op=29999 RESULT err=0 tag=101 nentries=1 etime=0.001000
[13/Mar/2014:16:32:57 +0000] conn=5 op=30000 SRCH base="o=test.com" scope=2 filter="(uid=SUser)" attrs=ALL authzid="uid=puser,o=test.com"
[13/Mar/2014:16:32:57 +0000] conn=5 op=30000 RESULT err=0 tag=101 nentries=1 etime=0.001000
[13/Mar/2014:16:34:04 +0000] conn=5 op=30002 UNBIND
[13/Mar/2014:16:34:04 +0000] conn=5 op=30002 fd=66 closed - U1

You can see the memory grow with this command:
for((i=0;;++i)) { echo `date` ` grep VmSize /proc/\`pidof ns-slapd\`/status | grep -o '[0-9]*'`; sleep 1 || break; }

Note that when the connection/search finishes, the memory is not freed. If you run the test again it will grow again from the new baseline. The original (more complex and slow) load test caused the ns-slapd process to be aborted due to out-of-memory after around a week.