This subsection describes how to investigate the life cycle of a session using a trace based performance analysis.

You can investigate the life cycle of a session by using the trace (Session trace) that is output when the PRF trace collection level is set as details.

You can investigate a session trace information by using the session ID of the trace based performance analysis file that is output or the global session ID (when the memory session fail over function is used), as a key.

The session ID is output to the option area of the event, output as the session trace information in the following format:

 
Number of session characters: Session ID
 

For example, if there is a session ID called as abc123, in the option area 6:abc123 is output. When the session ID is a blank character, 0: is output as the number of session characters. When the session ID cannot be acquired, nothing is output.

In the case of a global session ID as well, the session ID is output in the same format.

The session ID of the identified event is acquired from a URL when the Cookie or URL of the request header is overwritten. You can confirm from where the session ID is acquired referring to the character that is output at the end of the session ID. When the session ID is acquired from a Cookie, C is output following the session IDs that are output to these events. When a session ID is acquired from a URL, U is output following the session ID. The following are the events where you can confirm the acquisition source of the session ID:

• 0x8000 (After a request for processing a request is acquired)
• 0x8002 (Receive a request for an HTTP request body from a Web container)
• 0x8102 (Send and receive an HTTP request body to the Web container)
• 0x8200 (Acquire a request through the Web server and complete the analysis of the request header)

The following figure gives an example of trace based performance analysis file in which the session trace information is output. In this example, the trace information of a request to generate a session, a request to use the session, and a request to destroy the session are output in the validity period of one session. Also, a request to generate a session, a request to use the session, and a request to destroy the session are shown separately. In reality, the trace information in these three examples is output one after another. In these windows, all items are related to the session trace.

Figure 7-13 Example of trace based performance analysis file where the session trace information is output (request part where the session is created)

1. In the ASCII example of the 0x8208 event, the generated session ID is output. 60 in the option column indicate the session validity period.
2. In the ASCII example of the 0x8300 event, the generated global session ID is output.
   

   Figure 7-14 Example of the trace based performance analysis file where the session trace information is output (request part where the session is used)

   

3. Indicate the session IDs acquired from the Cookie of a request header.
   

   Figure 7-15 Example of the trace based performance analysis file where the session trace information is output (request part where the session is cancelled)

   

4. In the ASCII example of the 0x8209 event, the session ID of the destroyed session is output. The operation example describes the generation time of the destroyed session.
5. Indicates that the global session is destroyed. The cancelled global session ID is not output.

The items that you can confirm in this trace file are described here.

Confirming the validity period of the session

When generating a session, the 0x8208 event is output. When destroying a session, the 0x8209 event is output. You can confirm the validity range of the session from the date and time of these acquisitions. Also, in the case of the 0x8208 event, you can even confirm the validity period (seconds) of the session generated from the operation name.

The same ID is output to the event 0x8209 of the request to destroy the session until the session is destroyed. You can confirm the date and time of generating the session that is destroyed from the operation name.

Confirming the validity period of the global session (in the case of the memory session failover function)

You can confirm the validity period of the global session based on the global session ID that is output. The global session ID indicates that the session inherited between redundant J2EE servers is unique, if you use the memory session failover function. For details, see 6.4.1 Global session ID in the uCosminexus Application Server Compatibility Guide.

When a global session ID is generated, the global session ID is output following the session ID at the identified trace collection points.

In Figure 7-13, the global session ID is generated at the timings of the event 0x8300 in the request to generate a session, and that ID is output. The same global session ID is output until the request processing finishes in the event 0x8209 of the request to destroy the session.