[AOLSERVER-COMMITS] aolserver/tcl pools.tcl,1.4,1.5

[<gne...@us...>]

Update of /cvsroot/aolserver/aolserver/tcl
In directory 23jxhf1.ch3.sourceforge.com:/tmp/cvs-serv24700/tcl

Modified Files:
	pools.tcl 
Log Message:

New configure parameter "spread" for ns_pools: 

  Background: Requests are distributed to idle threads via CondSignal,
  which delivers subsequent signals to idle threads in a circular
  manner (i.e. t1, t2, .. tn, then t1 again) determined by the
  scheduling policy of the operating system. This round robin behavior
  has the disadvantage that multiple threads terminate about at the
  same time, based on the maxconnections (or maxconns) value. The idle
  timeout will never be used on a sufficiently busy server.  The mass
  termination of threads is performance-wise bad, especially when many
  connections threads are configured, since it is likely that about
  the same amount of threads will be recreated.

  The "spread" parameter introduces a random factor into threadtimeout
  and maxconnections to avoid these termination cycles.  It adds +/-
  the specified percentage to maxconnections and threadtimeout (e.g. a
  spread of 20 means a random value between 0.80 to 1.20 of the
  specified value of maxconnections and threadtimeout for every
  connection thread).
  


Index: pools.tcl
===================================================================
RCS file: /cvsroot/aolserver/aolserver/tcl/pools.tcl,v
retrieving revision 1.4
retrieving revision 1.5
diff -C2 -d -r1.4 -r1.5
*** pools.tcl	1 Aug 2007 22:30:51 -0000	1.4
--- pools.tcl	27 Dec 2008 00:36:39 -0000	1.5
***************
*** 36,41 ****
  set maxconns [ns_config $cfgsection maxconnections 0]
  set timeout [ns_config $cfgsection threadtimeout 0]
  
! ns_pools set default -minthreads $minthreads -maxthreads $maxthreads -maxconns $maxconns -timeout $timeout
  
  ns_log notice "default thread pool: [ns_pools get default]"
--- 36,42 ----
  set maxconns [ns_config $cfgsection maxconnections 0]
  set timeout [ns_config $cfgsection threadtimeout 0]
+ set spread [ns_config $cfgsection spread 20]
  
! ns_pools set default -minthreads $minthreads -maxthreads $maxthreads -maxconns $maxconns -timeout $timeout -spread $spread
  
  ns_log notice "default thread pool: [ns_pools get default]"