Winibndd's increasing RSS memory issue.

[Ravindra Channabasappa]

Starting a new thread about winibndd's increasing RSS memory issue. This issue was partially discussed in another thread-
https://lists.samba.org/archive/samba-technical/2014-April/099268.html


We have Samba-4.1.3 with MIT Kerberos and external keytab is being used.

Before the performance test (of 10K user login) is run the winbindd process memory statistics shows:
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bash-4.1# ps -eo pid,ppid,pcpu,pmem,vsz,rss,command | grep winbindd

27033 26799  0.0  0.2  29228 12084 /sbin/winbindd --interactive --stdout --configfile=/etc/samba/7.conf --log-basename=/home/runtime
27059 27033  0.0  0.1  29452  5616 /sbin/winbindd --interactive --stdout --configfile=/etc/samba/7.conf --log-basename=/home/runtime
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VSZ and RSS size - (29452  5616)


But once test with 10K users is completed, the VSZ and RSS increase to (31892 14408) and never come down.
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bash-4.1# ps -eo pid,ppid,pcpu,pmem,vsz,rss,command | grep winbindd
27033 26799  0.0  0.2  29228 12112 /sbin/winbindd --interactive --stdout --configfile=/etc/samba/7.conf --log-basename=/home/runtime
27059 27033  0.5  0.3  31892 14408 /sbin/winbindd --interactive --stdout --configfile=/etc/samba/7.conf --log-basename=/home/runtime
**********

As discussed/suggested in another mail thread I ran valgrind and found that there is hardly any leak in the memory (max 40 bytes).
valgrind output of winbindd is attached. Note, valgrind output is of another instance of the run with different pids.

In the above run, RSS size increases from ~5 MB to ~14M.
>From the SMAP output of the process, I see that winbindd_cache.tdb and netsamlogon_cache.tdb are majorly contributing to RSS size increase.
This is expected as the number of logged in users have increased.

But the problem is RSS size does not seem to come down. Isn't  it a problem for long living winbindd processes?

Files attached:


Thanks,
--ravindra




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