[horde] php and postgres, Re: Horde 3.1, memcache sessionhandler, sidebar, and flock()

[Chris Stromsoe]

On Tue, 2 Jan 2007, Chuck Hagenbuch wrote:
> Quoting Chris Stromsoe <cbs at cts.ucla.edu>:
>
>> The more I look at this, the more it looks like here is either In any 
>> event, I'm stumped about where to look.  Is anybody else using postgres 
>> and shares/datatree seeing the same issues (extremely long lag times to 
>> create the first instance of a share) ?
>
> I haven't seen this specific issue, but I do have speed issues in Ansel 
> listing photo galleries (mysql this time, so I don't think this is pgsql 
> specific). I'm looking at various remedies; unfortunately for me 
> removing about 1,000 rows from horde_datatree (10,000 from horde_d_a) by 
> getting bookmarks into their own table didn't do a think for gallery 
> listing speed.
>
> I'm planning on doing more, looking into this + shares in plain SQL + 
> your data, but in the mean time, do you still see this as related to the 
> memcache session handler?

The memcache session handler was my first guess, mostly because of the 
flock() serialization changes.  I think that I can completely rule session 
handling out as the source of the problem.

I added calls to microtime() in the various DataTree routines and the PEAR 
DB routines, and traced the slowness I'm seeing down to DB/pgsql.php 
fetchInto(), specifically the pg_fetch_row() call.


I wrote some php code to simulate the same set of DB calls outside of 
Horde, but was not able to duplicate the problem independantly, so it 
looks like it isn't anything specific to the DB calls themselves, but 
probably to how memory allocation and garbage collection in PHP works.

I haven't had time to start digging into the PHP source to try to figure 
out where the slowness is coming from.  Since I only see it on additional 
calls to ->exists(), I added code to the postauthenticate hook to create 
the nag, kronolith, and mnemo shares if they don't exist, so that the 
first ->exists() will always be true.




-Chris