For details about defining CADL and CSDL, see the CICS System Definition Guide.
You need CSDL only if you use RDO and want to keep a log of commands.
The maximum length of data records written to CSDL is 128 bytes. If you define CSDL as extrapartition, the associated SDSCI or DD statement should specify V format records with a minimum blocksize of 136 bytes.
The length of messages issued by the JVM can vary, and the maximum record length for the CSSL queue (133 bytes) might not be sufficient to contain some of the messages you receive. If this happens, the sample output redirection class issues an error message, and the text of the message might be affected. If you find that you are receiving messages longer than 133 bytes from the JVM, you should redefine CSJO and CSJE as separate transient data queues. Make them extrapartition destinations, and increase the record length for the queue. You can allocate the queue to a physical data set or to a system output data set. You might find a system output data set more convenient in this case, because you do not then need to close the queue in order to view the output. If you redefine CSJO and CSJE, ensure that they are installed as soon as possible during a cold start, in the same way as for transient data queues that are defined in group DFHDCTG.