The ORA-12520 cannot find the available handler for the requested server type

The ORA-12520 listener cannot find the available handler for the requested server type:

The ORA-12520 listener cannot find the available handler for the requested server type:

Solution to ORA-12520 errors

The ORA-12520 listener cannot find the available handler for the requested server type:

1) The database is a dedicated server, but the connection mode is set to shared in the tnsname. ora configuration. In this case, enable tnsname. ora,

Change (server = shared) to (server = dedicate)

2) It is caused by insufficient process.

Later, I found that v $ process has risen to more than 140, and my database has set 150. Based on this, we can conclude that process is not enough. Use the following statement to modify the processes value of the database.

Alter system set processes = 500 scope = spfile (because processes is a static parameter, scope can only be spfile, in the v $ sgastate condition of 'procesees', we can see that each process will be 4 bytes ),

Restart the database to make the new processes take effect. Then re-run eclipse, you can start it normally.

Note: If you use hibernate in hibernate. connection. provider_class selects c3p0. This is the case, but it does not seem like any other. it is strange that c3p0 will open so many processs. In the shared connection mode, shared_server is the process value that has been connected to the database. Pay attention to this.

Current number of connections

Select count (*) from v $ process;

Set the maximum number of connections (default value: 150)

Select value from v $ parameter where name = 'processs ';

Modify the maximum number of connections

Alter system set processses = 300 scope = spfile;

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