[OpenAFS] UDP timeouts

Derek Atkins warlord@MIT.EDU
Mon, 09 May 2011 09:21:14 -0400

Jaap Winius <jwinius@umrk.nl> writes:

> Quoting Jeffrey Altman <jaltman@secure-endpoints.com>:
>> The next question is what do ip_conntrack_udp_timeout and
>> ip_conntrack_udp_timeout_stream actually control?  Are those values
>> "timeouts" from the last traffic seen or hard caps on how long a mapping
>> can exist?
>> It sounds like you are experiencing a hard cap.
> Yesterday I raised the values from 900 to 3600 to 7200 to 14400 and
> still saw dropped packets. Now I'm back to 28800 and they've
> disappeared.
> If it is a hard cap (although I'm still not certain of that), and if
> memory conservation is really what the original values are for (which
> is not too much of an issue for me), then 28800 sounds like it may not
> be so bad after all.

I thought that ip_conntrack timeouts were from last traffic seen, not
hard caps.  But I could be mis-remembering.  The Linux kernel changes
often enough that it wouldn't surprise me if they changed the behavior
without documenting it.  Historically I set the timeouts at 3600 and
wouldn't see issues.

> Cheers,
> Jaap


       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
       URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
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