NAME

dtpcclock - DTPC daemon task for managing scheduled events

SYNOPSIS

dtpcclock

DESCRIPTION

dtpcclock is a background "daemon" task that periodically performs scheduled DTPC activities. It is spawned automatically by dtpcadmin in response to the 's' command that starts operation of the DTPC protocol, and it is terminated by dtpcadmin in response to an 'x' (STOP) command.

Once per second, dtpcclock takes the following action:

First it executes all DTPC events scheduled to occur at any time up to the current moment:

DTPC ADUs for which an expected positive acknowledgment has not yet arrived are retransmitted.

Received DTPC ADUs whose time to live has elapsed are deleted.

Then dtpcclock increases the ages of all DTPC ADUs pending transmission and initiates transmission of each such ADU whose age now equals or exceeds its aggregation time limit.

EXIT STATUS

0

dtpcclock terminated, for reasons noted in the ion.log file. If this termination was not commanded, investigate and solve the problem identified in the log file and use dtpcadmin to restart dtpcclock.
1

dtpcclock was unable to attach to DTPC protocol operations, probably because dtpcadmin has not yet been run.

FILES

No configuration files are needed.

ENVIRONMENT

No environment variables apply.

DIAGNOSTICS

The following diagnostics may be issued to the ion.log log file:

dtpcclock can't initialize DTPC.

dtpcadmin has not yet initialized DTPC protocol operations.
Can't send finished adu.

An unrecoverable database error was encountered. dtpcclock terminates.
Can't stop aggregation for adu.

An unrecoverable database error was encountered. dtpcclock terminates.
Could not scan outbound Adus

An unrecoverable database error was encountered. dtpcclock terminates.

BUGS

Report bugs to <https://github.com/nasa-jpl/ION-DTN/issues>