HP Integrity NonStop H-Series - Manual (Page 68)

Scheduled Synchronization
HP AutoSYNC User’s Guide—522580-021
4-8
Scheduled Synchronization Flow
Scheduled Synchronization Flow
The following paragraphs describe how components of AutoSYNC interact to manage
and execute scheduled synchronizations:
Monitor Process
ASYSYNCP process
ASYSYNC process
Variant for Synchronization over TCP/IP
Monitor Process
The monitor process accesses the SYNCUSER table to determine the users that have
been configured by the administrator. Each user has various parameters such as
maximum priority. A user may be suspended, in which case it is ignored.
For each user ID, uuu,ggg, there should be a file set configuration table named
SFggguuu. All file sets in these tables are fetched to the monitor’s memory and sorted.
Suspended file sets are discarded.
The monitor starts a local ASYSYNCP process for each unique combination of user ID,
known destination system, and batch ID. If a destination system is not available, the
monitor waits for a system message that declares that the remote system is available,
and then starts the appropriate processes.
After starting the ASYSYNCP processes, the monitor sends a message to each
process, containing all file sets that pertain to that process.
The monitor maintains (and checkpoints) a table of ASYSYNCP processes and
periodically checks that these processes are still alive. If any process fails, or if there
are network or CPU failures that affect these processes, the monitor takes an
appropriate corrective action. Simple failures will be retried three times immediately
and then once every 30 minutes.
If the administrator or a user issues a command that updates the SYNCUSER or
SFggguuu tables, the monitor determines which tables have been changed and
refreshes its list of active file sets. The monitor then analyzes what changes have been
made; the monitor can start or stop ASYSYNCP processes or simply send a new set of
file sets to an existing ASYSYNCP process.
The monitor responds to STATUS requests by the AUTOSYNC Command Interpreter
with the cached list of file sets and ASYSYNCP processes.
Each monitor process can manage up to 1024 ASYSYNCP processes.
ASYSYNCP process
The ASYSYNCP process receives the list of file sets that have been assigned to it from
the monitor. It alters its process-access ID to the user ID that is associated with the file