This technote describes special considerations and issues for configuring a load balanced ClearQuest Web server environment to support OSLC integrations.
Resolving The Problem
Requirements for using OSLC integrations in a load-balanced ClearQuest Web deployment
- Using OSLC integrations in a load-balanced ClearQuest Web deployment is supported starting with ClearQuest version 220.127.116.11. Technote 1579391 describes the problems that can occur when attempting to use ClearQuest Web server as an OSLC provider in a load-balanced deployment prior to ClearQuest version 18.104.22.168. If your environment currently works around these problems by using a single ClearQuest Web server in an otherwise load-balanced environment, see Technote 1645802
- Store the OSLC configuration settings as master properties in the schema repository.
- All servers in the load-balanced environment must run the same version of Rational ClearQuest.
- All machines in the load-balanced environment must be able to resolve the machine names and/or IP addresses of all other machines in the load-balanced environment so that the requests can be forwarded to the appropriate server as needed.
- Ensure that every machine in the load-balanced environment has access to the same database connections. Each database connection must be consistently named across all machines in the load-balanced environment.
- In environments where different versions of WebSphere and/or IBM HTTP Server are used, review information about mixed-version compatibility in Technote 1160581. You must use a version of WebSphere and IBM HTTP Server supported by the Rational ClearQuest version in use.
General troubleshooting topics
- If the load-balanced ClearQuest environment makes use of non-standard port suffixes (*80 for http and *43 for https), both the IBM HTTP Server and the WebSphere Application Server must be configured to use the same protocol. The https protocol is preferred. If the servers are not configured properly, you might see the following error message:
Error '401: invalid_expired_token'
- In some cases, the ClearQuest Web server data on a specific server in an OSLC load-balanced environment can become stale. Because ClearQuest Web server data is refreshed at each login operation, you can refresh stale data by logging into the server. To prevent stale data across your environment, you might want to create an automated process to log into the ClearQuest Web servers after configuration changes or other scenarios that require refreshing the ClearQuest Web servers. Some scenarios where a refresh might be required include:
- ClearQuest is installed or re-installed on a particular server
- A new database connection is added to a ClearQuest server
- Configuration changes occur while a ClearQuest server is stopped
- A ClearQuest server stops unexpectedly
For ideas about automating the log in process, see Technote 1644559.
- In some cases, load-balanced ClearQuest Web servers that are running in a virtualized environment might use the wrong IP address when forwarding OSLC requests. See Technote 1645815 for information on how to diagnose and correct this issue.
Related Technote topics
- Technote 1644559 - How can the active OSLC configuration settings be refreshed on all servers in a load balanced ClearQuest environment?
- Technote 1644136 - Best practices when using OSLC integrations with a load balanced ClearQuest MultiSite environment
- Technote 1643365 - Load balanced ClearQuest systems may return an error '401: invalid_expired_token' when attempting to establish a project relationship
- Technote 1643251 - OSLC provisional key can only be authorized from a single server in a load balanced system
- Technote 1646293 - Process changes when performing a CLM server rename when the OSLC configuration settings are stored as master properties
16 June 2018