In our SAS environment, SAS Stored process server has 9 multibridge connection. Maximum cost=500
session cost=1, context cost =100, cost per client=1
Hence according to theory, 4 requests can execute on one multibridge connection simultaneously.
So total of (9*4=36) requests should execute in parallel on the SAS Stored process server.
But when I open 12 tabs in a browser and hit one SAS stored process URL at the same time(with a very time gap of miliiseconds), what i observe is that, only 6 requests get executed at a time. and when 6 request completes its execution then next 6 requests gets executed.
In the STP log, it is observed that all 12 requests are being submitted only on 6 multibridge connections port.
So my question is, why not all 12 request to SAS Stored process from a single user are not executed at the same time on SAS STP server?
If you set the Object Spawner's IOM.LoadBalancing logger to TRACE the Object Spawner log will provide detail on the cost algorithm's process.
You can set this logger in SAS Management Console by right-clicking on the host under the Object Spawner and selecting "Connect", then under the loggers tab locate the logger "IOM.LoadBalancing" and double-click or right-click and select "Properties", then change it's setting from Inherited to Assigned: Trace.
You can change this back after reproducing the behavior.
-- Greg Wootton | Principal Systems Technical Support Engineer