Running the MSNL Master
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The MSNL master is an Ultrix program which requires the pthreads
library in order to compile and run. Internally the master is
multi-threaded. The master must be run with root privileges, to
enable it to open and use the MSNL control socket. It also needs to
be configured with several environment variables which describe where
the master can obtain information on the configuration of the system
which it is managing, where it should write its log, and what
responses it should deliver when responding to rarp requests. The
environment variables which are required are:
- MSNL_MASTER_LOG: the full path them of the log file to
which the tracing information printed by the master will be logged.
This file will never exceed 10000 lines in length. It is
periodically closed and restarted.
- MSNL_MASTER_CONFIG: the name of the configuration file
which the master will read on start up and whenever it is signaled
to reread its configuration and rarp tables (see below).
- MSNL_MASTER_RARPD: the full path name of the file
containing the rarp table for the rarp daemon. If this is a non
existent file, or does not contain valid information then the rarp
daemon will not start. This will not affect the behavior of the
master in any other way. This is the correct way to prevent the rarp
daemon from starting. This file will be reread when the signal
(described below) is given to the master to get it to reconfigure.
- MSNL_MASTER_BOOT: the MSNL address of the boot server
which should be configured as the default boot server for all rarp
requests which do not have a boot server address encoded in the rarp
table. The format of this variable is an MSNL address in Internet
dotted notation.
To reconfigure the master, the appropriate files should be edited (for
example the rarp table) and the manager reinitialised by sending it
the signal SIGHUP. On receipt of this signal the rarp tables
will be discarded and the MSNL master will reread both the
configuration file and the rarp tables. An error in either file will
have the same results as if the master had just been started, namely
an error in the configuration file will cause the master to fail,
close the control socket and exit. An error in the rarp table will
prevent the rarp daemon from starting.
Next: File Formats
Up: MSNL Connection Management Using
Previous: The Rarp Server
Simon Crosby