TMF Planning and Configuration Guide (H06.05+)
Reconfiguring TMF Processes
HP NonStop TMF Planning and Configuration Guide—540136-002
6-2
Monitor Processes (TMFMON and TMFMON2)
Monitor Processes (TMFMON and TMFMON2)
The monitor processes, TMFMON and TMFMON2, run in every processor in an HP
NonStop server.
The TMFMON processes are responsible for the highest-priority, critical operations and
are always fully resident. They are primarily responsible for allocating the memory
segments used by the TMF library (TMFLIB) data structures. They also detect when
disk volumes go up and down and notify the TMP of those changes.
The TMFMON2 processes are each created and started by the associated TMFMON
process. They are primarily responsible for resynchronizing the TMFLIB data
structures in their processor after processor failures and reloads. They also clean up
TMFLIB and disk process data structures after TMF crashes or is stopped abruptly.
Transaction Management Process (TMP)
The transaction management process (TMP) coordinates distributed transactions and
the TMF configuration. One TMP process pair, named $TMP, in each HP NonStop
server runs TMF. The primary TMP process is created by the TMFMON2 process
when a processor configured for the TMP is reloaded.
The TMP is responsible for coordinating transactions whose execution is distributed
over a network. It is also in charge of all operations that require a single point of
control in the system, such as starting and stopping TMF, initiating the recovery
processes, and implementing configuration changes. The TMP manages the data
volumes and audit trails, and is the final authority in deciding whether transactions
should be committed or aborted. It also creates other TMF processes as needed.
Backout
Whenever a transaction is aborted, the backout process backs out any changes that
the transaction made to the database, thus leaving the database in a consistent state.
There is always at least one backout process per system. The backout processes are
created by the TMP when TMF is started and are terminated when TMF is stopped.
Up to three additional copies of the backout process are created according to the
number and types of processors in the system. Backout processes are named $XBKn,
where n is a digit uniquely identifying the particular process.
If a backout process stops or abends while TMF is running, the TMP automatically
restarts it.