10.8 Migrating CMAN Sessions During Patching

You can migrate the established client/server sessions from one Oracle Connection Manager (CMAN) instance to another Oracle CMAN instance during a planned upgrade or patching of Oracle CMAN with zero downtime.

You can migrate live sessions with data in-transit without disrupting the service. Any operations that are running either on a client or on a server continue to run seamlessly during the migration without loss of service. You can also add new client connections during the migration.

Perform the following steps to migrate client/server sessions:

You must have either upgraded Oracle CMAN to the latest release or applied the latest patch.

1. Install the upgraded Oracle CMAN or the patched Oracle CMAN in a new ORACLE_HOME.
2. Use the same cman.ora file that you used for configuring Oracle CMAN to configure the new Oracle CMAN instance.
3. Start the new Oracle CMAN instance from the new ORACLE_HOME in migration mode. Use the following command:

   cmctl startup –migrate -c cman_alias

   This command starts a new Oracle CMAN instance and initiates migrating of sessions from old Oracle CMAN instances. An old Oracle CMAN instance will exit as soon as the migration is complete or after 7 minutes timeout.

   The address of the old Oracle CMAN instance is added in the cman.ora file with the alias, cman_alias_old. You can use this alias to control and check the status of old Oracle CMAN instance during migration.

You can migrate sessions in the following scenarios:

• If both client to Oracle CMAN and Oracle CMAN to server use TCP.
• If either a client or a server uses TCPS (TLS) on one end and TCP on the other end. You must install Oracle Database 21c or later on both, the client using TCPS and the server using TCPS.

Unsupported connections remain connected till the timeout duration.

Note:

• Session migration is supported only for Oracle CMAN in regular mode and not for Oracle CMAN in Traffic Director Mode.
• If both client to Oracle CMAN and Oracle CMAN to server use TCPS, then migration is not supported.
• Currently, session migration is not supported on Microsoft Windows.