ZE3 ICM not coming up

There was a application server redesign activity last week where in we were involved in shutting down some application servers in backend /communication zones and changing parameters as per SAP TPO recommendations. But the issue came in where half of the processes in SM50 were showing in running status and other were in stopped status, when we reverted back the values of rdisp/wp_no_dia and btc it came again with correct status.

The logs were showing the database errors, we tried to connect to database and it showed connected to an idle instance even though the SAP system was working.

It immediately striked to us that database is not accepting more connections, we checked the value of V$session variable using following query;

The number of sessions the database was configured to allow

Select name, value from v$parameter WHERE name = 'sessions';

The number of sessions currently active

Select COUNT(*) from v$session;

for more info follow the below link
http://stackoverflow.com/questions/162255/how-to-check-the-maximum-number-of-allowed-connections-to-an-oracle-database


Though the connections were increased but still Business wanted justification on what basis the connections were increased.

We checked the ICM connection in SMICM in one of the instances was showing RED, we reverted the settings and it came up again, because of that the Adobe services and all JCo connections failed.