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Migrating Oracle9iAS Web Cache

This chapter explains the functionality of the Web Cache migration option. It contains the following topics:

• Web Cache Migration Candidates for Migration from Release 1 (1.0.2.2.x)

• The Web Cache Migration Process: Migrating from Release 1 (1.0.2.2.x)

• The Web Cache Migration Process: Migrating from Release 2 (9.0.2)

• The Web Cache Migration Process: Migrating from Release 2 (9.0.2)

• The Web Cache Migration Process: Migrating from Release 1 (1.0.2.2.x)

• Backup and Auditing Measures for Web Cache Migration

• Completing the Web Cache Migration

Web Cache Migration Candidates for Migration from Release 1 (1.0.2.2.x)

When you migrate from Release 1 (1.0.2.2.x), the Migration Assistant recognizes most of the elements in the webcache.xml file in ORACLE_HOME_1. They are listed in "The Web Cache Migration Process: Migrating from Release 1 (1.0.2.2.x)" below.

Web Cache Migration Candidates for Migration from Release 2 (9.0.2)

When you migrate from Oracle9iAS Release 2 (9.0.2), all customization values are migrated to the Oracle9iAS Release 2 (9.0.3) instance, except:

• ORACLEHOME

• IDENTITY

• LOGDIR

• MULTIPORT

• OSWALLET

These values remain as specified by the Oracle9iAS Release 2 (9.0.3) installation.

Migration of Session Definitions

A session definition consists of a session name, a cookie, a URL parameter, and a default value. The Migration Assistant migrates session definitions as follows:

• If the session name, cookie, URL parameter, and default value, are the same in the source installation as in the target installation, then the session definition is not migrated.

• If the session name is the same, but the cookie, URL parameter, or default value is different, then the Migration Assistant migrates the session as it is, changes the name of the target session, and updates its references.

  Warning: Any application that was using WEBCACHETAG with reference to the original target Web Cache session definition must be modified to use the re-named session definitions.

Web Cache Elements Not Migrated

The Assistant does not migrate the MULTIVERSIONHEADERRULE, if the Host header is used for disambiguation. Web Cache in Oracle9iAS Release 2 (9.0.2) supports multiple sites. See the Web Cache documentation for site-to-server mapping.

The Assistant does not migrate the internal.xml and internal_admin.xml files (which contain values such as buffer sizes and network time-outs).

The Web Cache Migration Process: Migrating from Release 2 (9.0.2)

When you migrate from Release 2 (9.0.2) to Release 3 (9.0.3), the 9.0.2 webcache.xml file is unchanged by the Migration Assistant, except for certain values, retained from the 9.0.3 installation:

• ORACLEHOME

• IDENTITY

• LOGDIR

• MULTIPORT

• OSWALLET

If the 9.0.2 version of webcache.xml contained all of the necessary customization, no post-migration tasks are necessary.

The Web Cache Migration Process: Migrating from Release 1 (1.0.2.2.x)

The Web Cache migration option does the following copies the following elements of the webcache.xml file from ORACLE_HOME_1 to ORACLE_HOME_2:

• SECURITY

  SECURESUBNET (Sub-element of SECURITY; trusted subnets).

  Note: The Migration Assistant does not migrate any passwords. The administrator and invalidation passwords have default values when Release 2 is installed; see the Web Cache documentation for the default passwords.

• WATCHDOG

• REQUESTBACKLOGTIMELIMIT (an attribute of the SITE element)

  Copied to the first SITE element of the webcache.xml file in ORACLE_HOME_2.

• ERRORPAGES

  Copied to the ORACLE_HOME_2 webcache.xml file under the first SITE element.

• MULTIVERSIONCOOKIESRULE

  Merged with the data in the same sections of the GLOBALCACHINGRULES element in the webcache.xml file in ORACLE_HOME_2. This can result in duplicate or redundant multi-version cookies rules. See "Completing the Web Cache Migration" for instructions on resolving this.

• SESSIONCACHINGRULE

  Copied to the ORACLE_HOME_2 webcache.xml file, in the GLOBALCACHINGRULES section. This can result in duplicate or redundant session caching rules. See "Completing the Web Cache Migration" for instructions on resolving this.

• EXPIRATIONRULE

  Merged with the data in the same sections of the GLOBALCACHINGRULES element in the webcache.xml file in ORACLE_HOME_2. This can result in duplicate or redundant expiration rules. See "Completing the Web Cache Migration" for instructions on resolving this.

CACHEABILITY

Copied to the ORACLE_HOME_2 webcache.xml file, in the GLOBALCACHINGRULES section. This can result in duplicate or redundant cacheability rules. See "Completing the Web Cache Migration" for instructions on resolving this.

Note: Since the migrated CACHEABILITY rules are defined in the GLOBALCACHINGRULES section, they apply to all of the SITES defined in the ORACLE_HOME_2 webcache.xml file. If you define another SITE element later in ORACLE_HOME_2, you must also define cacheability rules for it. The rules defined in the GLOBALCACHINGRULES section will apply to the new SITE also.

• HOST

  All of the application web servers from the ORACLE_HOME_1 webcache.xml file are migrated to the ORACLE_HOME_2 webcache.xml file. Host IDs are generated for each of these hosts.

• EVENTLOG

• ACCESSLOG (except for the LOGDIR attribute)

• RESOURCELIMITS

Backup and Auditing Measures for Web Cache Migration

The Assistant performs the following functions to provide a way to audit the migration process:

1. Creates a backup copy of the webcache.xml file from ORACLE_HOME_2. The backup file is named webcache.xml.backup.

2. Logs all migration activity and errors in

   ORACLE_HOME_2/migration/log/iASMigration.log (UNIX)

   ORACLE_HOME_2\migration\log\iASMigration.log (Windows)

Completing the Web Cache Migration

To complete the Web Cache migration, you may need to perform the tasks in this section after the Migration Assistant has executed.

Note: These tasks are always necessary after migrating from Release 1. If you are migrating from Release 2 (9.0.2), and the Web Cache configuration files were migrated from Release 1, but the tasks in this section were not performed at that time, then you must perform them when migrating to Release 2 (9.0.3).

Use the Web Cache Administration user interface to review and, if necessary, change the configuration as follows:

Note: If, because of a port conflict, the Web Cache administration process does not start, you must specify the correct administration port in the MULTIPORT element of the webcache.xml file, and restart Web Cache.

• Create the site-to-server mappings.

• To use the same Operations Port or Listening Port wallets as in Release 1, obtain the wallet information from Release 1 and modify the wallet information in Release 2, using the Administration user interface.

• Review post-installation user changes.

  The Migration Assistant can be invoked any time after the Oracle9iAS Release 2 (9.0.3) installation. If changes were made to the webcache.xml file, they are preserved. There may be redundant cacheability rules. You must review the file to resolve these. The rules themselves, and the order in which they appear, determine the caching behaviors executed by Web Cache.

• Resolve any port conflicts introduced by the migration.

  Port numbers are not migrated from the webcache.xml file. Compare the Release 1 and Release 2 webcache.xml files to ensure that there are no port conflicts after the Migration Assistant has executed.

  Web Cache does not migrate administration, listen, statistics, and invalidation port numbers. To use the Release 1 port numbers in Release 2, perform the following steps:

  1. Determine the Web Cache port numbers used in Release 1.

  2. Use the Administration user interface to change the port numbers in Release 2.

• Review session caching rules and resolve any duplications.

• Review expiration rules and resolve any duplications.

• Review multi-version cookies rules and resolve any duplications.

Synchronizing Oracle9iAS Web Cache and Oracle HTTP Server Ports

Web Cache and the Oracle HTTP Server have runtime interdependencies. When Web Cache runs in front of OHS, the elements and directives shown in the table below are related:

Web Cache Element	Corresponding OHS Directive
Site definitions	VirtualHost
Origin server ports	Listen
Site-to-server mappings	Virtual Host, Listen
Listen	Port

After migration, these Web Cache elements will be exactly as they were in Release 2 (9.0.2). In the Release 2 (9.0.3) instance, compare the Web Cache and OHS configurations to ensure that:

• If Web Cache has an OHS hostname as an origin server, that origin server points to the Listen port specified by OHS.

• The Web Cache listening port is the same port specified by the OHS Port directive.

• The ports in the site-to-server mapping properly correspond.