AIPS HELP file for TPMON in 31DEC20
As of Thu Jul 9 21:43:52 2020
Type: A system daemon for receiving remote AIPS tape/disk requests
Use: TPMON is a program that runs outside of AIPS itself, though it
can be started as a result of starting AIPS. Its purpose is to
run autonomously (like the system daemons, e.g. inetd), and
accept remote requests from other computers on the network. The
description here is mainly intended for the AIPS manager and is
of minor interest to the end user.
Each tape drive on a given system has a single TPMON dedicated to
it. This is achieved by hard links TPMON2, TPMON3, etc. in the
load area, to TPMON.EXE. When TPMON starts up, one of the first
things it will do is basically ask "who am I" by getting the
number in its name. TPMON1 is a special case reserved for access
to FITS disk areas; thus, TPMON2 is reserved for accessing the
first local tape, TPMON3 for the second, and so on. See the help
on MOUNT for how to access remote FITS disk areas.
The TPMON daemons can be started in one of two ways: either by
starting up AIPS in the normal way, or explicitly via the
START_TPSERVERS script. If you add the "-d" argument to this
script (which is located in $AIPS_ROOT), additional diagnostic
messages will be emitted by the startup scripts, and the output
from the TPMONs will not be suppressed (it otherwise is). AIPS
Managers may want to divert the stdout and stderr from such a
command (e.g. specified in AIPS.BOOT) to a log file.
The manner in which AIPS remote tape operation is achieved is
relatively simple: if a MOUNT or FITLD or FITTP, etc. request is
made on your local host for a resource (tape or disk file) on a
remote host, a socket connection is made to the appropriate port
on the remote host. The socket/service names are set in the file
/etc/services (or the YP services map), usually during the AIPS
installation, and for remote tape/disk access are named aipsmt0,
aipsmt1, and so on. aipsmt0 will be used to communicate with
TPMON1, aipsmt1 with TPMON2, and so on.
The AIPS manager will set up a file in $NET0 called TPHOSTS. Its
purpose is to list the hosts that are allowed to connect to your
TPMON daemons. It is VERY IMPORTANT that this file be set up
correctly, so that you restrict incoming connections to trusted
hosts. The format of this file is simple: one hostname per line,
with a single pseudo-wildcard allowed at the beginning of each
line (or the end for IP addresses). For example:
would permit access from the following:
1) any hostname that ended in ".foobar.edu";
2) the host "glock.com";
3) any IP address in the 192.33.115 family, e.g. 126.96.36.199;
4) the host at IP address 188.8.131.52.
The entries in this file should begin in the first column. Blank
lines, or lines beginning with a "#" character are ignored. The
current maximum number of (non-comment, non-blank) lines in
TPHOSTS is 512.
As shipped, AIPS will have a single line in this file with the
word "localhost". You (the AIPS manager) will have to edit this
file in the course of installation, or all remote access will be
If you do not wish to grant FITS disk access to your local
systems, you can simply kill the TPMON1 process anytime after it
starts. This may be a good idea, though it may be useful to
enable it temporarily if you wish NRAO to access a file for
debugging or problem-solving purposes.