PI message archiving

Hello

I have recently been made responsible for a PI 7.1 system, and am new to SAP and PI. I have some general questions about message archiving and would be grateful for some advice.

I understand that message details are saved to SXMSPMAST and associated tables. There is a limit to the number of rows in the tables.

Q. What happens when the tables are full?

Q. Is it possible to increase the number of rows that they can hold?

I believe that none of our existing interfaces have been configured for archiving/retention.

Q. Should the interfaces have been configured for archiving before first use?

Q. Does this only apply to asynchronous interfaces?

The vast majority of messages in SXMXPMAST have ITFACTION set to 'INIT'. I understand that these messages will not be deleted or archived.

Q. Is it possible to change the ITFACTION and is this something I should be doing?

Q. There are some synchronous messages with a status of system error on our system. I am not able to cancel these messages in SXMB_MONI. I do not want to keep a record of these messages as they were sent before the system was 'live'. Is there anything I can do to delete them?

I have found several documents on the SAP forums and blogs, but none deal with the case where existing interfaces haven't been configured for archiving.

Kind regards

Steve