For a HiRDB parallel server configuration, you can select one of the following message log output methods (message log output destinations):

1. Message logs are output to the message log files and to syslogfile of the server machine where the system manager is defined.
2. Message logs are output to the message log files and to syslogfile of a server machine. In this case, a message is output to the server machine that issued the message.

Normally, message logs are output using method 1. If necessary, change to method 2. Method 2 is called message log output dispersion.

You use the pd_mlg_msg_log_unit operand to select the desired method. If this operand is omitted, the default is method 1.

The following figures show message output methods 1 and 2.

Figure 8-2 Normal message log output method (method 1)

Figure 8-3 Message log output method when message log output dispersion is used (method 2)

Reference note

When you use the pdcat command to view message logs, you will view the message logs of the unit in which the pdcat command is executed. For this reason, if message log output dispersion is used, you must execute the pdcat command at the unit where the desired message logs to be viewed are located.

Table 8-1 Message log output methods shows the message log output methods; Table 8-2 Advantages and disadvantages of the message log output methods shows the advantages and disadvantages of each message log output method.

Table 8-1 Message log output methods

Method selected#	Condition	Message log output destination
Method 1 (manager)	During normal operation	Message logs are output to the message log files and to syslogfile of the server machine where the system manager is defined.
	When an error or communication error occurs at the manager unit	Message logs are output to syslogfile of each server machine. Only some message log information is output. Also, the correct message logs might not be output.
Method 2 (local)	During normal operation	Message logs are output to the message log files and to syslogfile of each server machine.
	When an error or communication error occurs at the manager unit

#: The value in parentheses ( ) is the value specified in the pd_mlg_msg_log_unit operand.

Table 8-2 Advantages and disadvantages of the message log output methods

Method selected#	Advantage	Disadvantage
Method 1 (manager)	Because message logs can be centrally managed from the server machine of the system manager, the job of monitoring messages is simpler than when local is specified.	If the system manager unit shuts down or a communication error occurs between the system manager unit and other units, the correct message logs might not be output.
Method 2 (local)	Correct message logs are output even if the system manager unit shuts down or a communication error occurs between the system manager unit and other units.	Because message logs are output to each server machine, the job of monitoring messages is more complicated than when manager is specified.

#: The value in parentheses ( ) is the value specified in the pd_mlg_msg_log_unit operand.

The following shows the environment settings for using message log output dispersion.

Procedure

1. Because message log files are created in each server machine, you must re-evaluate your estimate of message log file size. Specify the revised result in the pd_mlg_file_size operand.
2. Specify local in the pd_mlg_msg_log_unit operand.
3. Synchronize the time-zone settings in all server machines.
   

   Reference note

   If the time-zone settings are not synchronized among the server machines, the times in the additional information in the message logs that are output to the various server machines will be different. Therefore, when you view the message logs, you will have to take into account the time-zone differences among the server machines.

• When you use JP1/BASE (or JP1/SES) to monitor messages, you must monitor syslogfile of all server machines.
• When you specify PD_MLOG for the records to be collected by JP1/Performance Management - Agent Option for HiRDB, only the message logs that are output by the server machine where the system manager is defined are collected.