exec

 

Description

Provides basic framework services for PIMs, DIMs, Jugglers, and Daemons.

 

Configuration Variables

There are several configuration variables that describe or control how the executive operates. The subset listed below can be modified by the user. There are others that are intended for future use or for information only.

id

An identifier used to label some PAM output windows. Can be set to anything that makes sense to the user.

DIMThreadCount

By default there is one thread available for DIMs to execute in. This may be changed.

PIMThreadCount

By default there are two threads available for PIMs to execute in. This may be changed.

concurrencyLimit

This is the number of simultaneous executions of any PIM or DIM instance. Default value is 1. You should increase this value only if you are experimenting since the results will depend on whether the PIM or DIM were written to support simultaneous execution of the same instance. As of the revision date no check has been made to guarantee that PIMs and DIMs support concurrent execution from different threads.

proxyHost, proxyPort

These tell PAM to use the specified host and port as an HTTP proxy. Note that FTP operations will not work via the proxy.

serverPortNumber

Identifies the HTTP port used for built-in web services. This port should not be the "public" web access point. PAM should be configured with a "real" peer web service to handle high volume queries.

peerProtocolHostAndPort

A URL that specifies the peer web service. Default port is 80. Example:

(peerProtocolHostAndPort "http://pushtech.mitre.org")

 

How it works

The executive is configured via a plain text file that by default is in the directory 0checkpts in a file called ckpt.txt. When PAM is run from the command line a different directory and file may be used as the only command argument. If enabled, PAM will automatically perform checkpoints into 0checkpts/ckpt.txt . The checkpoint file is in the same format as the startup file. Thus PAM may be initially started from a custom startup file and subsequently restarted from autogenerated checkpoint files.

Revised: 10 Dec 1997