Concerns when configuring Rational Team Concert

Authors: DanToczala
Build basis: CLM 2011 (product versions 3.x) and later

Configuring Rational Team Concert should be simple and straightforward for most initial implementations. There should not be too many things to consider during the initial configuration of Rational Team Concert. After the application is deployed, sometimes performance issues dictate that you consider tuning the JVM settings of Rational Team Concert.

General concerns

When you consider how to configure Rational Team Concert, it is critical to know the workload that Rational Team Concert will support, and the expected user load on the solution. It is also essential to know how the Rational Team Concert instance is related to the Jazz Team Server, and how the Jazz Team Server will control licensing and user access to the resources being managed by the Rational Team Concert instance. Make sure that sufficient licenses are available for your user community, and that user authentication and roles have been considered when configuring the Jazz Team Server.

Hardware needs

In general, an instance of Rational Team Concert should have at least 2 cores associated with it, and 4 cores if the instance is planned to be used by a larger number of users (more than 50 users).

It should also have at least 4 GB of JVM heap memory available to use for processing, and this amount might need to be tuned and increased depending on the workload (see Tuning Rational Team Concert). When you initially configure Rational Team Concert, there should also be an equal amount of memory available for the operating system, so a total of 8 GB of memory should be available to support a single Rational Team Concert instance. Some solutions with lighter workloads might be able to achieve satisfactory performance with less memory, but this is considered a good starting point.

The Rational Team Concert instance should also have a fast network connection between itself, the Jazz Team Server instance, and the database instance. In an ideal scenario, these will all reside on the same subnet, but they should at least have a minimal number of network hops, and by physically co-located (that is, in the same data center) for acceptable performance.

The Rational Team Concert instance will also need disk storage. This storage is used by the operating system, as well as by the Rational Team Concert instance itself for the storage of configuration settings and index files. Making 40 GB of hard drive storage available is usually sufficient.

Configuration settings

A Rational Team Concert instance comes with a default set of configuration parameters. For initial implementations, these default settings provide the best option. There are some default options that you might like to modify, to improve the overall performance and stability of your Jazz deployment.

Limiting feed traffic

In deployments with a large number of end users with the Eclipse client, the Eclipse client requests for feed traffic can put a large load on the Jazz system. You have the ability to throttle, or reduce these feed requests. For deployments supporting over 200 concurrent users we strongly suggest throttling these feed requests. Feeds are useful for finding out what is going on in a project, but in general they only need to be updated every 30 minutes or so. The defaults are typically Note that each Jazz application server (the CCM, RM, QM, and even the JTS) has it's own feed update interval settings. Here is how you can change those default update intervals, and limit the amount of feed traffic on your Jazz server:

1. Go to the Administration Console for the Jazz application.
2. Select the Server page
3. Select "Feed Settings" under the Configuration option in the left side menu bar.
4. In the feed configuration properties, find out:
   • Is "Feed Query Maximum Entries" more than 200? You probably don't want to return more than 100 feed events for any feed query.

• The following options are available in version 4.0.3 or greater:
  • Is the Feed Throttle Management Enabled is set to true? You want this set to true to throttle feed processing.
  • Is "Update feed automatically" checked? If so, what is the update interval set for? Every 30 minutes should be sufficient.
  • Is "Reload feed automatically on startup" checked? You may want to disable this.
  • Is "Override server configuration" checked? This allows clients to override the server settings.
  • Is "Limit number of items" checked? If so, what is the value for "Maximum news items"? You probably don't want more than 100.
  • Is "Limit age of items" checked? If so, what is the value for "Days to keep news items"? You probably only want to keep items for 7 days.

For more information, see work item 255974. Note that only RTC 4.0.3 clients support the Feed Throttling feature at this time

Limiting the size of attachments

Attachments eat up DB space, and they hog bandwidth. Limiting the size of these can help immediate performance and long term performance of your system. The default limit on attachment size is 50MB (as of v4.x), but you can adjust this. I would strongly suggest adjusting it lower, and never higher than 50MB. Here is how you can do it:

1. Login to RTC (CCM) as the admin user
2. Go to Advanced Properties
3. Search for the com.ibm.team.workitem.service.internal.WorkItemRepositoryService entry in Work Item Component
4. Edit the Maximum Attachment Size to a required value and save the changes

Scalability

Keep in mind that any single Jazz solution might contain multiple Rational Team Concert instances. As you reach the limits of what a single Rational Team Concert instance can support, there is no way to move projects to new Rational Team Concert instances, and no way to move workload off of the existing Rational Team Concert instance.

For this reason, you should consider the deployment of new Rational Team Concert instances in a Jazz solution proactively, and you should do so before performance issues become apparent on the existing Rational Team Concert instance or instances.

Use of content caching proxies

The use of content caching proxies allows a solution to offload some of the processing that is associated with the retrieval of files from the SCM system with Rational Team Concert. The establishment of a content caching proxy will allow requests for frequently accessed source code to be satisfied by the content caching proxy, instead of having the request get routed to the Rational Team Concert instance, having the Rational Team Concert instance request the resource from the database, and then return this to the requesting user or process. In solution environments where there are frequent builds, these proxies can greatly reduce the load on both the Rational Team Concert application instance and on the database supporting that instance.

See the section on concerns when using a content caching proxy.

Configuring the Java Virtual Machine (JVM) settings

One of the most important things that you configure are the JVM settings that are used when you deploy the Jazz Team Server. These settings often have a large impact on the performance of your Jazz Team Server application, and you should have these tracked somewhere as part of your solution architecture description. Often, it is best to start with the default JVM settings suggested by the development team.

Related topics: Configure the JVM settings, Tuning the JVM settings, Tuning Rational Team Concert, Concerns when using a content caching proxy

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