TMF Planning and Configuration Guide (H06.05+)

Reconfiguring TMF Processes

HP NonStop TMF Planning and Configuration Guide—540136-002

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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.