Appdenix C. Testing and Debugging Commands

Log Central provides a number of testing and debugging utilities. This appendix describes how to:

Generating Test Messages

Log Central provides a program called msg_test to test the flow of messages. You can observe the results of your test messages with the Message Browser of the Log Central Console. The msg_test utility generates a user-defined number of messages and sends them according to the settings specified in its options. You can also use msg_test to print performance data.

To generate test messages, run the msg_test command at a command prompt on the central host or a managed node, with the following syntax:

msg_test [-h] [-i] [-l length] [-m log_level] [-n messages]
[-s subsystem [subsystem]] [-t interval]

The msg_test command options definitions follow.


Argument	Description
`-h`	Displays a help message.
`-i`	Invokes the interactive mode. The `-i` option overrides the `-t` option.
`-l` `length`	Defines the message body length. The default length is 40.
`-m` `log_level`	Specifies one or more logging levels to use in the message header. `log_level` is one or more of the following: `N` - Normal (the default) `V` - Verbose `D` - Debug `S` - Special
`-n` `messages`	Defines the number of messages you want to generate. The default is 1.
`-t` `interval`	Defines the time interval, in seconds, to sleep between messages. The default is 0.
`-s` `subsystem`	Specifies the subsystem name to use in the message header. You can specify more than one subsystem. The default is `LC`. You can supply a list of subsystem names.

Examples

This command simply generates three random messages:

msg_test -n 3

The following two commands are equivalent; each generates three messages. The subsystem name of the first message is LC, the second is TUXEDO, and that of the third is LC (because it is not specified, and thus uses the default).

msg_test -n 3 -s "LC TUXEDO"

msg_test -n 3 -s LC -s TUXEDO

Reading the Current Intermediate Log File

The msg_reader utility continuously reads the current intermediate log file that the msg_receiver process constructs, and writes the contents of this file to the standard output stream. The data appears in stdout in message format (that is, in a string containing header data and body text).

The msg_receiver process creates a new intermediate log file every hour. The msg_reader process automatically switches to reading the current log file, which the msg_server process updates hourly. It tracks the current log file, and automatically switches to a new log file whenever the msg_server closes an old log file and opens a new one. The msg_reader process displays the contents of the intermediate log file on the standard output, allowing you to monitor the file without going through the Console.

To read the current log file, run the msg_reader command at a command prompt on the central host, with the following syntax:

msg_reader [ -e  ] [ -n  ] [ -h  ] pathname

The msg_reader command options definitions follow.


Argument	Description
`-e`	Starts writing from the end of the log file.
`-n`	Formats the logged messages before writing them. Do not use this option if you invoke the `msg_reader` along with the `log_monitor` application.
`-h`	Displays a help message.
`pathname`	Specifies the path and file name to open for reading. The `msg_reader` utility takes `pathname` as an argument, adds the extension `.cur`, and opens the resulting file for reading. The `pathname` value is the intermediate file prefix for Log Central.

Examples

The following command invokes msg_reader with formatting options and opens the file named /tmp/log1 for reading:

msg_reader -n /tmp/log1 &

The following command prints messages to stdout with formatting:

msg_reader -n pathname &

Use the following command to specify your own parameters:

msg_reader [-e] [-n] pathname &