Troubleshooting
Problem
Symptom
Threads are erroring out with ORA-00018 database connection error when the number of application threads increases.
The application tried to execute a statement that requested a resource. Since the maximum number of sessions has been reached, Oracle will not process any new resource requests.
ORA-00018: maximum number of sessions exceeded error, not able to connect to DB
Resolving The Problem
The options to resolve this Oracle error are:
1. One can wait a few minutes and try to re-execute the statement(s).
- This can be considered only when enough sessions are configured in database and this is one time occurrence due to some additional testing.
2. One can shut down Oracle, increase the SESSIONS parameter in the initialization parameter file, and restart Oracle.
- Customer should verify the "No. of sessions (PROCESSES)" at Oracle and set proper value for the same based on the application requirement.
As per earlier observations, PROCESSES = 300 is an average number for MCF application, but can vary based on customer configurations.
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Document Information
Modified date:
18 June 2025
UID
swg21559053