5. Repository Service
As we already discussed about metadata repository, now we discuss a separate,multi-threaded process that retrieves, inserts and updates metadata in the repository database tables, it is Repository Service.
Repository service manages connections to the PowerCenter repository from PowerCenter client applications like Desinger, Workflow Manager, Monitor, Repository manager, console and integration service. Repository service is responsible for ensuring the consistency of metdata in the repository.
Creation & Properties:
Use the PowerCenter Administration Console Navigator window to create a Repository Service. The properties needed to create are,
Service Name – name of the service like rep_SalesPerformanceDev
Location – Domain and folder where the service is created
License – license service name
Node, Primary Node & Backup Nodes – Node on which the service process runs
CodePage – The Repository Service uses the character set encoded in the repository code page when writing data to the repository
Database type & details – Type of database, username, pwd, connect string and tablespacename
The above properties are sufficient to create a repository service, however we can take a look at following features which are important for better performance and maintenance.
> OperatingMode: Values are Normal and Exclusive. Use Exclusive mode to perform administrative tasks like enabling version control or promoting local to global repository
> EnableVersionControl: Creates a versioned repository
Node Assignments: “High availability option” is licensed feature which allows us to choose Primary & Backup nodes for continuous running of the repository service. Under normal licenses would see only only Node to select from
> DatabaseArrayOperationSize: Number of rows to fetch each time an array database operation is issued, such as insert or fetch. Default is 100
> DatabasePoolSize:Maximum number of connections to the repository database that the Repository Service can establish. If the Repository Service tries to establish more connections than specified for DatabasePoolSize, it times out the connection attempt after the number of seconds specified for DatabaseConnectionTimeout
> CommentsRequiredFor Checkin: Requires users to add comments when checking in repository objects.
> Error Severity Level: Level of error messages written to the Repository Service log. Specify one of the following message levels: Fatal, Error, Warning, Info, Trace & Debug
> EnableRepAgentCaching:Enables repository agent caching. Repository agent caching provides optimal performance of the repository when you run workflows. When you enable repository agent caching, the Repository Service process caches metadata requested by the Integration Service. Default is Yes.
> RACacheCapacity:Number of objects that the cache can contain when repository agent caching is enabled. You can increase the number of objects if there is available memory on the machine running the Repository Service process. The value must be between 100 and 10,000,000,000. Default is 10,000
> AllowWritesWithRACaching: Allows you to modify metadata in the repository when repository agent caching is enabled. When you allow writes, the Repository Service process flushes the cache each time you save metadata through the PowerCenter Client tools. You might want to disable writes to improve performance in a production environment where the Integration Service makes all changes to repository metadata. Default is Yes.
The database client code page on a node is usually controlled by an environment variable. For example, Oracle uses NLS_LANG, and IBM DB2 uses DB2CODEPAGE. All Integration Services and Repository Services that run on this node use the same environment variable. You can configure a Repository Service process to use a different value for the database client code page environment variable than the value set for the node.
You might want to configure the code page environment variable for a Repository Service process when the Repository Service process requires a different database client code page than the Integration Service process running on the same node.
For example, the Integration Service reads from and writes to databases using the UTF-8 code page. The Integration Service requires that the code page environment variable be set to UTF-8. However, you have a Shift-JIS repository that requires that the code page environment variable be set to Shift-JIS. Set the environment variable on the node to UTF-8. Then add the environment variable to the Repository Service process properties and set the value to Shift-JIS.