Negotiation processing is a process that confirms whether preference information of the Web application to be started matches with the information stored on the EADs server at the time of starting a Web application that uses the EADs session failover functionality.

If result of the negotiation processing indicates that the preference information matches, the Web application is started. If the preference information does not match, one of the following processes is executed:

• KDJE34453-E, KDJE34406-E, or KDJE34407-E, indicating that the preference information did not match in the negotiation processing that was output, and that starting of the Web application was canceled. Take actions as per the output message.
• KDJE34409-I, indicating that the preference information did not match in the negotiation processing is output, and processing of starting the Web application continues.

If application information acquired from the EADs server is invalid, KDJE34452-E is output and starting of the Web application is canceled. Take action as per the output message.

This subsection describes the contents confirmed in negotiation.

(a) Web applications are matching

If all of the confirmation items in the table below match with the information saved in the application cache, it is determined that the applications are matching. The following table describes the confirmation items and operations performed when the confirmation items do not match, and output messages:

Table 7-9 Items used to confirm matching of Web applications

No.	Confirmation item	Operation when items do not match	Message output when items do not match
1	Application identifier#	Starting of the Web application continues (handled as a different application).	--
2	J2EE application name	Starting of the Web application is canceled.	KDJE34453-E
3	Web application name (context root name)

Legend:

--: Not applicable

#

For details on application identifiers, see (4) Application identifiers.

(b) Settings of all web applications are matching

The processing checks whether settings of all replicated Web applications match with the information saved in the application cache, with regard to the confirmation items described in the table below. The following table describes the confirmation items, operations performed when the confirmation items do not match, and output messages:

Table 7-10 Items used to confirm matching of settings of all Web applications

No.	Confirmation item	Operation when items do not match	Message output when items do not match
1	Upper limit of the number of HttpSession objects	Starting of the Web application continues.	KDJE34409-I
2	Validity of HTTP session defined in DD (web.xml)
3	URL pattern that inhibits the EADs session failover functionality	Starting of the Web application is canceled.	KDJE34406-E
4	URL pattern of refer-only requests

(c) J2EE server settings are matching

The processing checks whether settings of all replicated J2EE servers match, with regard to the confirmation items described in the table below. The following table describes the confirmation items, operations performed when the confirmation items do not match, and output messages:

Table 7-11 Items used to confirm matching of settings of all J2EE servers

No.	Confirmation item	Operation when items do not match	Message output when items do not match
1	URL pattern that inhibits the EADs session failover functionality	Starting of the Web application is canceled.	KDJE34406-E
2	URL pattern of refer-only requests

(d) EADs server settings are correct

The processing checks whether the conditions described in the table below are satisfied. The following table describes the confirmation items, operations performed when the confirmation items do not match, and output messages:

Table 7-12 Conditions used to confirm whether EADs server settings are correct

No.	Condition	Operation when items do not match	Message output when items do not match
1	Required cache is available on theEADs server.	Starting of the Web application is canceled.	KDJE34407-E

First, preference information of the Web applications, which were successful in the negotiation processing, is saved in the application information cache on the EADs server. Then, with negotiation, preference information of the Web applications and preference information saved in the application information cache are compared, and it is confirmed whether the contents match.

Therefore, if you want to change preference information of a Web application, you need to delete preference information related to the change target Web application that is already saved in the application information cache on the EADs server. For details on how to delete preference information, see 7.7.2 Initializing application information.

Application identifiers are names used for identifying the clustered Web applications when using the EADs session failover functionality. By default, the system automatically generates application identifiers.

Application identifiers are used in negotiation processing to confirm whether Web applications are matching. Therefore, an application identifier must meet the following conditions:

• An application identifier matches with the same Web application, which operates on replicated J2EE servers.
• An application identifier is a unique value in the system.

If an application identifier that is automatically generated by the system does not satisfy a condition, you need to define a value that satisfies the conditions. For details on how to define an application identifier, see 7.4 Defining with cosminexus.xml.

The following subsections describe the rules for automatically generating application identifiers and examples of automatically generated application identifiers:

Note

If the same application identifier is set to different Web applications, the second Web application fails in negotiation when starting and does not start.

(a) Rules for automatically generating an application identifier

By default, a string based on context root name is automatically set in application identifiers. If an application identifier is automatically generated, the applicable value is output to the message log with the KDJE34402-I message when starting the Web application.

The following rules are applied when automatically generating an application identifier on the basis of context root name:

• Delete forward slash (/) at the beginning.
• If the length of the string exceeds 128 characters, excluding the forward slash (/) at the beginning, use a string of up to 128 characters.
• If characters that cannot be used in an application identifier are used in the context root name, replace the characters with underscores (_).
  You can use only alphanumeric characters (A - Z, a - z, and 0 - 9) and underscores (_) in an application identifier. Set values are case-sensitive.
  
• In root context, change to ROOT and not to a blank string.

If you apply the rules for automatic generation, application identifiers might not remain unique in the system. In that case, the second Web application, to which the same application identifier is set, fails in the negotiation processing when starting and does not start. Therefore, it is essential to set an application identifier that is unique in the system for a Web application.

(b) Examples of automatically generated application identifiers

The following table shows examples of default application identifiers, which are automatically generated from context root name:

Table 7-13 Examples of automatically generated default application identifiers

No.	Context root name	Application identifier	Rules applied when creating
1	/examples	Examples	Delete forward slash (/) at the beginning
2	/App01/test1	App01_test1	Delete forward slash (/) at the beginning Replace forward slashes (/) in between with underscores (_)
3	/	ROOT	Because this is root context, change to ROOT