[cvsnt] Strange CVS performance fluctuation

[Trevor Leybourne]

Just some ideas and feedback if it will help, 

We've been having similar and significant problems here as well. Our CPU
rarely goes above about 5-10% usage (even with 10-20 cvs.exe processes
---- it's a fairly grunty Windows 2003 Server) and yet a checkout that
would normally take less than 15 minutes will take more than a hour when
multiple people are accessing it. 

Our IT guys have spent a lot of time evaluating the issue and the issues
has been resolved as being disk contention (see timer results below). 

We found that running on a server with Raid 1 was costly and have moved
the disk array to Raid 5 instead (no significant difference between SAN
and LOCAL disk). 

Also, if you are using something like CruiseControl for your build
process, look at the URL Build Trigger rather than the standared build
trigger. The standard build trigger uses a CVS LOG command to look for
changes and this is a significant process to run against a large
repository. 

We ran a test of having 3 PCs each running 3 concurrent checkouts
against CVS. Here are the results against different disk configurations
and are in Minutes. The repository size is around 850Mb and a checked
out Sandbox is 540Mb (6,000 files in 250 folders)
 
	(RAID5 Local) (RAID1 Local) (RAID5 SAN)	   
Test1	14	77	15	   
Test2	15	77	15	   
Test3	14	76	15	   
Test4	16	78	16	   
Test5	16	77	16	   
Test6	16	77	16	   
Test7	16	72	17	   
Test8	16	78	17	   
Test9	16	79	16	  

The CVS Server is 2.5.02.2115 and the client was 2.5.03.22650

Cheers
Trevor

-----Original Message-----
From: cvsnt-bounces at cvsnt.org [mailto:cvsnt-bounces at cvsnt.org] On Behalf
Of Tobias Rodenbach
Sent: Wednesday, 21 June 2006 1:41 a.m.
To: cvsnt at cvsnt.org
Subject: [cvsnt] Strange CVS performance fluctuation

Hello,

I observed the following strange behaviour, when "many" people tried to
access our cvs server (I counted about 35 instances of cvs.exe).
Then, the CPU usage history of the Windows Task Manager shows that CPU
Usage goes to about 50% for about 10 seconds, then drops to below 3% for
about 10 seconds, rises to about 50% for 10 seconds and so on...
Sometimes CPU usage stays high or low for more than 10 sec but most of
the time it alternates in the 10 second scheme.

In general, the performance is very low. Checking out using a tag (which
is the most common case here) can take up to one hour for around 6 MB in
the local LAN. ("Normally" that takes significantly less than one
minute.)

The host is a Win2003 server with 2 hyperthreading CPUs, the cvsnt
server is version 2.5.02 build 2115.

Does anyone have any idea what could be the reason for this behaviour?

Best regards
 Tobias
_______________________________________________
cvsnt mailing list
cvsnt at cvsnt.org
http://www.cvsnt.org/cgi-bin/mailman/listinfo/cvsnt
######################################################################
Attention: 
This e-mail message is privileged and confidential. If you are not the 
intended recipient please delete the message and notify the sender. 
Any views or opinions presented are solely those of the author.

######################################################################