Simultaneous Connection Considerations
When connections are being established simultaneously over Oracle Net Services (SQL*Net) to Oracle Database Exadata Express Cloud Service, there are certain parameter settings to consider in order to avoid intermittent errors during connection establishment.
Intermittent Error
If you are trying to establish a number of simultaneous connections, which may be from the use of a connection pool, or there are transient load scenarios, you may intermittently encounter the following error: ORA-28865: SSL connection closed
.
Workaround
You may reduce the initial pool size and/or minimum pool size to reduce the number of simultaneous connection requests. The specific parameters depend on the pool being used by the application.
You can also add RETRY_COUNT and RETRY_DELAY parameters to the connect string in tnsnames.ora if 12.1.0.2 (or higher) version of client is used. Please start with a value of 1, and tune upwards as needed. See RETRY_COUNTand RETRY_DELAY in Oracle Database Net Services Reference.
If the issue persists, contact Oracle Support for assistance.