How To Ensure Load Balancing Of Concurrent Manager Processes In PCP-RAC Configuration

There are 2 types of resources in use for PCP/RAC:

1.O/S processes for manager and requests

2.Shadow processes for database connection for managers and requests.

O/S processes for managers (e.g. FNDLIBR, etc.) and request processes (ar60run, sqlplus, etc.)will run on primary node defined for manager.Shadow processes for database connection use load balanced alias (s_cp_twotask) and the load isdistributed between database nodes by sqlnet. This is controlled by sqlnet and CP code is notinvolved. This should mimic what happens to sqlplus connections using load balanced alias forRAC. The following sql can be used to check how manager connections are spread:

select inst_id, count(*) from gv$session where process in (select os_process_id from fnd_concurrent_processes where process_status_code = 'A') group by inst_id;

Now to loadbalance the shadow concurrent manager processes please set the below :

1.Set the profile option "Concurrent: PCP Instance Check" to "OFF"
2.Set the context variable s_cp_twotask to '_806_BALANCE' (This entry can be found in the tnsnames.ora file). You have to set this in both RAC nodes.

3.Run autoconfig and after that you can check for the loadbalancing aspects

How To Enable Debugging For Concurrent Managers?

1. Enable DIAG for the ICM, by modifying script
$COMMON_TOP/admin/scripts/SID_hostname/adcmctl.sh as follows :
Replace line : CONTEXT_PARAMS="diag=N wait=N" With : CONTEXT_PARAMS="diag=Y wait=N"
Save file.

2. Enable the Debug Service if not yet enabled :
- Login with System Administrator responsibility
- Navigate to Concurrent / Manager /Define
- Query manager with name "Debug Service"
- tick the "Enabled" checkbox if not yet ticked
- save

3. Stop and restart the concurrent managers
Don't forget to switch it off after the debug information has been generated.