ORA-12516 error with oc4j SOA suite

One of the common errors I see when running the SOA suite from oracle is the ORA-12516 error. This typically happens in a development environment where the backend database is oracle XE. The root cause of the issue is the XE process is running out of sessions/process threads as the default values for these in XE is too small. To fix the error, verify the current values for the processes and sessions and increase them to atleast 300.

To increase the sessions and process use the following sqls.

sqlplus "sys as sysdba"
SQL> show parameter processes;
SQL> show parameter sessions;

If the values are less than 300, set them to 300 using the following sqls,

SQL> alter system set processes=300 scope=spfile;
SQL> alter system set sessions=300 scope=spfile;
SQL> shutdown immediate
SQL> startup

Now, restart the oracle process using the following commands.

opmnctl stopall
opmnctl startall