Essbase 11.1.2 - AgtSvrConnections Essbase Configuration Setting
By Ann Donahue on Apr 10, 2012
AgtSvrConnections is a documented Essbase configuration setting used in conjunction with the AgentThreads and ServerThreads settings. Basically, when a user logs into Essbase, the AgentThreads connects to the ESSBASE process then the AgtSvrConnections will connect the ESSBASE process to the ESSSVR application process which then the ServerThreads are used for end user activities. In Essbase 11.1.2, the default value of the AgtSvrConnections setting was changed to 5. In previous Essbase releases, the AgtSvrConnections setting default value is 1.
It is recommended that tuning the AgtSvrConnections settings be done incrementally by 1 or 2 maximum and based on the number of concurrent Set Active/Clear Active calls.
In the Essbase DBA Guide and Technical Reference, the maximum setting recommended is to not exceed what is set for AgentThreads, however, we have found that most customers do not need to exceed a setting of 10. In general, it is ok to set AgtSvrConnections close to the AgentThreads setting, however, there have been customers that needed an AgentThread setting greater than 10 and we have found that the AgtSvrConnections setting higher than 5-10 could have a negative impact on Essbase due to too many TCP ports used unnecessarily. As with all Essbase.cfg settings, it is best to set values to what is needed based on process load and not arbitrarily set to high values.
In order to monitor and tune the AgtSvrConnections setting, monitor the application log for logins and Set Active/Clear Active messages. If there are a lot of logins and Set Active/Clear Active messages happening in a short period of time making it appear that the login is taking longer, incrementally increase the AgtSvrConnections setting by 1 or 2, which can then help with login speed. The login performance tolerance is different from one customer environment to another since there are other factors that can impact this performance i.e. network latency.
What is happening in Essbase when a user logs in:
- ESSBASE issues a Set Active to the ESSSVR process. Each application has its own ESSSVR process.
- Set Active then calls MultipleAsyncLogout and waits on the pipe connection.
- MultipleAsyncLogout goes back to ESSBASE.
- ESSBASE then needs to send the logout back to the ESSSVR process.
- When the AgtSvrConnections setting needs to be increased from the default of 5, it is because Essbase cannot find a connection since the previous connections are used by ESSBASE-ESSSVR. In this example, we may want to increase AgtSvrConnections from 5 to 7 to improve the login performance.
Again, it is best to set Essbase settings to what is needed based on process load and not arbitrarily set to high values. In general, stress or performance testing environments using automated tools may need higher than normal settings. This is because automated processes run at high speeds for logging in and logging out. Typically, in a real life production environment, the settings are much closer to default values.