[Nss-mysql-devel] [ 101504 ] id command VERY slow

[nobody]

Support Request #101504, was updated on 2002-Nov-07 16:26
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Category: None
Status: Open
Priority: 5
Summary: id command VERY slow

By: marcus
Date: 2002-Dec-03 18:15
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Browser: Mozilla/4.0 (compatible; MSIE 5.15; Mac_PowerPC)

Hi Guillaume

Thanks very much for your reply, but I'm afraid none of 
your suggestions have made much difference. In fact, 
the problem is getting worse. The ls command is also 
very slow if the files being listed are owned by a user 
stored in the nss-mysql database.

I have tried optimising and even rebuilding the mysql 
database, but to no avail - and all of the important fields 
are definitely indexed. I have also tried tuning the mysql 
server with loads of extra memory etc, but still no 
change. I have even tried updating glibc (to 2.2.4-31) in 
case the newer nss api is faster.

nss-mysql is not in debug mode, it was built with the 
defaults (./configure). Also, unfortunately I can't use 
nscd as users must be able to change their username 
without having to wait for the cache to refresh. I could 
make them wait as a last resort, but I'm reluctant to as I 
don't think this is really addressing the cause of the 
problem.

Any more ideas would be very gratefully received.

Kindest regards

Marcus

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By: gmorin
Date: 2002-Nov-07 17:08
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user_id=230
Browser: Mozilla/5.0 (X11; U; Linux ppc; en-US; rv:1.1) Gecko/20020915 
Debian/1.1-1

Hi Marcus,

I understand your point. The problem is that id makes
several hundreds nss API calls in your case. That is why you
see so many queries. nscd implements some caching for nss
information. Unfortunately, it seems to be buggy and
triggers some weird bugs. 

But one minutes looks very long even for your number of
users. Are you sure you have not compiled nss-mysql in debug
mode which would slow it down significantly ? Since you saw
the nss-mysql queries, you should consider using the
"explain" command of MySQL to see if the query uses an index
which would speed things up.

If it's still too slow, try to install nscd and see if that
helps. 

HTH.

Guillaume.

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