Technical Blog Post
Why am I getting dumps from db2fmp process' when DB2 engine is up and running
db2fmp process are Fenced Mode Process' which are run outside of DB2's main address space.
Not-Fenced -> Runs inside DB2's address space. Example, SQL procedures, C Stored Procedures.
Fenced -> Runs outside of DB2's address space. Those use db2fmp process' which are not part of db2sysc process. Example, Java, C Stored Procedures and User Defined Functions (UDF).
This is a way to run a non-DB2 code as part of procedures or, functions inside DB2. If it's run as Not-Fenced then it will run in DB2's address space. So, any code bug in those procedures and functions will bring down the entire DB2 engine.
The fenced procedures are used to avoid that kind of DB2 crash. Instead, it will crash only the db2fmp process' and cause associated dumps. But, not affect running of the main DB2 engine.
So, if it's noticed that dumps are getting generated from db2fmp process' the first thing should be checked is, what products or, applications are owning the code as part of those procedures/functions and involve the product team to find the cause of the crashes. The application providing those codes might have their own diagnostic ways which might help to find the source of the problem.
In rare situations it might be a defect related to DB2's infrastructure or, some tuning need related to resources in the box and in specific users.