3.2.4 hwstraceinfo

Synopsis

hwstraceinfo -i shared-memory-identifier {-l file-name|-r}

Storage location

Application Server installation directory/httpsd/sbin

Function

When an application program is executed and a request is received, the events that occur in the system are collected as internal trace. The internal trace is output once to the shared memory, and then it is output to the file as per the specification in the directive or command.

Collecting trace information

Internal traces are collected in the shared memory when various events occur in the Web server. The memory identifiers of shared memory are stored in the file specified in the HWSTraceIdFile directive.

How to output to a file

The internal trace that is collected in the shared memory is output to a file when the server process terminates abnormally or when the hwstraceinfo command is executed. When the server process terminates abnormally, the trace is output to the file specified in the HWSTraceLogFile directive.

Specify the memory identifier and file name of output destination, in the hwstraceinfo command.

The internal trace information output file size is as follows:

(size of output from the ps -efl command) + (size of output from the the vmstat command) + (size of output from thethe ipcs -a command ) + (7KB x MaxRequestWorkers value)

Execution permission

Superuser or general user

Arguments

-i shared-memory-identifier

This parameter specifies the shared memory identifier that is output to the file specified in the HWSTraceIdFile directive.

-l file-name

This parameter specifies the file that outputs the trace corresponding to the shared memory identifier specified with -i.

-r

This parameter releases the shared memory allocated to the shared memory identifier specified in -i.

The shared memory for trace remains even if the Web server stops. Use this parameter to release the remaining shared memory.

Notes

To retain trace information, the Web server does not release the shared memory even when the Web server stops. The shared memory is reused when the server restarts.

When you stop the server and restart it later, the Web server releases the shared memory once and then restores it depending upon the file value specified in the HWSTraceIdFile directive. However, in the following cases, the shared memory used earlier cannot be released:

• When the same user does not restart the server (the User directive value or the Group directive value has changed)

• The value of the HWSTraceIdFile directive has changed

• The file specified in the HWSTraceIdFile directive is deleted

When you release the shared memory, execute the hwstraceinfo command in which -r is specified.