Subversion (with Apache) goes into slow motion

[Jens-Uwe Mager <ju...@anubis.han.de>]

We have it occasionally on our Server with svn 1.0.4 that the subversion
server inside Apache (we do only allow access via http:) goes into slow
motion. Any action be it local on the same machine or via a remote
client via the http: protocol proceeds very slowly. If I stop apache and
do a svnadmin recover everything is back to normal. I did just now
manage to strace Apache while it is in slow motion and it looks
basically like this:

pread(14, "N\6\0\0\2155\3\0\34\0\0\0\33\0\0\0\0\0\0\0\233\0\344\3"..., 4096, 114688) = 4096
select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout) pread(15, "N\6\0\0d\300\5\0\336\1\0\0\335\1\0\0\23\0\0\0*\0\224\1"..., 4096, 1957888) = 4096
select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)
pread(12, "K\6\0\0\'$\n\0a\r\0\0T\r\0\0\374\2\0\0\206\0h\1\1\5\364"..., 4096, 14028800) = 4096
select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)
pread(18, "N\6\0\0000\371\2\0i\v\0\0\0\0\0\0\0\0\0\0\301\0\360\3\2"..., 4096, 11964416) = 4096
pread(18, "K\6\0\0\3\377\t\0b\0\0\0\266\v\0\0\270\v\0\0<\0p\10\1\5"..., 4096, 401408) = 4096
pread(19, "N\6\0\0U\31\3\0\217\272\0\0\0\0\0\0\0\0\0\0\221\0\360\6"..., 4096, 195620864) = 4096
pread(19, "K\6\0\0\300\375\t\0\256\322\0\0\255\24\0\0/\25\0\0,\0\4"..., 4096, 220913664) = 4096
select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)

As one can see, the process does deliberatly sleep for one second using
the select system call for every few reads, no wonder anything takes
nearly forever. Why is it doing that?

-- 
Jens-Uwe Mager	<pgp-mailto:F476EBC2>

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Re: Subversion (with Apache) goes into slow motion

["C. Michael Pilato" <cm...@collab.net>]

Jens-Uwe Mager <ju...@anubis.han.de> writes:

> As one can see, the process does deliberatly sleep for one second using
> the select system call for every few reads, no wonder anything takes
> nearly forever. Why is it doing that?

Possibly a loop waiting for Berkeley DB locks?  I dunno for sure.

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