Informatica PowerCenter 8x Key Concepts – 5

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.

General Properties

> 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

Database Properties

> 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

Advanced Properties

> 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.

Environment Variables

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.

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Informatica PowerCenter 8x Key Concepts – 4

owerCenter Client (contd)

Workflow Manager : In the Workflow Manager, we define a set of instructions called a workflow to execute mappings we build in the Designer. Generally, a workflow contains a session and any other task we may want to perform when we run a session. Tasks can include a session, email notification, or scheduling information.

A set of tasks grouped together becomes worklet. After we create a workflow, we run the workflow in the Workflow Manager and monitor it in the Workflow Monitor. Workflow Manager has following three window panes,Task Developer, Create tasks we want to accomplish in the workflow. Worklet Designer, Create a worklet in the Worklet Designer. A worklet is an object that groups a set of tasks. A worklet is similar to a workflow, but without scheduling information. You can nest worklets inside a workflow. Workflow Designer, Create a workflow by connecting tasks with links in the Workflow Designer. We can also create tasks in the Workflow Designer as you develop the workflow. The ODBC connection details are defined in Workflow Manager “Connections “ Menu .

Workflow Monitor : We can monitor workflows and tasks in the Workflow Monitor. We can view details about a workflow or task in Gantt Chart view or Task view. We can run, stop, abort, and resume workflows from the Workflow Monitor. We can view sessions and workflow log events in the Workflow Monitor Log Viewer.

The Workflow Monitor displays workflows that have run at least once. The Workflow Monitor continuously receives information from the Integration Service and Repository Service. It also fetches information from the repository to display historic information.

The Workflow Monitor consists of the following windows:

Navigator window – Displays monitored repositories, servers, and repositories objects.

Output window – Displays messages from the Integration Service and Repository Service.

Time window – Displays progress of workflow runs.

Gantt chart view – Displays details about workflow runs in chronological format.

Task view – Displays details about workflow runs in a report format.

Repository Manager

We can navigate through multiple folders and repositories and perform basic repository tasks with the Repository Manager. We use the Repository Manager to complete the following tasks:

1. Add domain connection information, we can configure domain connection information.

2. Add and connect to a repository, we can add repositories to the Navigator window and client registry and then connect to the repositories.

3. Work with PowerCenter domain and repository connections, we can edit or remove domain connection information. We can connect to one repository or multiple repositories. We can export repository connection information from the client registry to a file. We can import the file on a different machine and add the repository connection information to the client registry.

4. Change your password. We can change the password for our user account.

5. Search for repository objects or keywords. We can search for repository objects containing specified text. If we add keywords to target definitions, use a keyword to search for a target definition.

6. View objects dependencies. Before we remove or change an object, we can view dependencies to see the impact on other objects.

7. Compare repository objects. In the Repository Manager, wecan compare two repository objects of the same type to identify differences between the objects.

8. Truncate session and workflow log entries. we can truncate the list of session and workflow logs that the Integration Service writes to the repository. we can truncate all logs, or truncate all logs older than a specified date.

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Business Intelligence Challenge – Product Upgrades & Migrations, Moving the Code – 4

Last time we discussed about Impact Assessment , the next logical step after this is to perform the actual upgrade or migration of the code.

Moving the Code: Performing Upgrade or Migration of the Objects

When we talk about product upgrades, always the product vendor provides tools by which the objects in the earlier version can be upgraded to the latest version. Yes we would see some objects failing through while using such tools; these are the ones that would need rework after the upgrade process.

When we talk about product migration like moving from Cognos to Business Objects or Business Objects to Cognos, there is good scope for us to look for some ways to automate the code migration. Earlier discussions have been on how to leverage the metadata for understanding the environment, now we are looking at an option on how to manipulate or transform the metadata so that an object in platform ‘A’ becomes compliant to platform ‘B’.

Steps involved in building an automated product migration process

Perform metadata level object mapping between the two platforms, determine the gaps. This would actually be a ‘by product’ of ‘Step 2’ in Impact Assessment

Build individual components that would

• Read the metadata from the source platform and prepare a repository
• Have the knowledge of the match & gap between the platforms, could be reference tables
• Transform the ‘source’ metadata and write out as understood by the ‘target’ platform by using the reference tables

Benefits of Automated Migration

• Helps avoid creation of objects from scratch
• Ensures availability of time for testing (core task) than code development
• Enables team to have a flexible skillset
• A faster way of delivering things when a ‘one to one’ migration from the source platform is seen as a must

Automated Migration Challenges

Transforming the source metadata to the target platform would be a challenge, especially with data manipulation functions. Having a good understanding of the gaps will help; a reference table mapping the functions between the platforms would be useful. In scenarios where a function cannot be converted to the target platform, a comment can be written into a log file enabling quicker attention.

Have seen good success in writing such automated migration components though not 100%. With almost every products providing good SDK kits for reading and as well writing metadata and as well with the support for XML structures, writing such bridges for object migration are getting easier.

Whether the objects in a product are migrated/upgraded in an automated way or not, the following activity of ‘Validation’ plays a key role in ensuring the final quality, next time let us discuss on some of the means for effective validation ….

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Informatica 8.6 Enhancements for Developers – 1

Informatica has released its latest version 8.6 covering all the hot fixes it released for the prior version 8.5 and including few new features. Since version 8, a Unified Admin Console has been designed for managing Integration and Repository services. These were discussed in earlier Blogs.

What does PowerCenter 8.6 bring new for the developers? Let us discuss PowerCenter 8.6 Client enhancements which will be useful to the developers.

1. Creating Targets from Transformations

We can create targets based on transformations in the workspace or navigator.

To create a target,

1. Right-click the transformation in the workspace and select the Create and Add Target option.

2. Alternatively, we can drag and drop the transformation in the Target Designer.

The target that is created has the same port definitions as the transformation from which it was created. We can edit the target definitions later. In addition, the target type is the same as that of the repository used.

2. Invalid/Invalidated renamed

In PowerCenter 7, the two states of objects were known as Invalid and Invalidated.

The exact meaning of these states is as follows:

Invalid – an object will not run,

Invalidated – an object may be invalid or may not run.

The difference between the two terms was not very clear. Therefore, to avoid any confusion, in PowerCenter 8.6, the two states have been renamed as Invalid and Impacted. While the Invalid state still implies that an object will not run, Impacted means that an object is affected by a change, and therefore, may not run.

Apart from the naming convention the icons are also changed in PowerCenter 8.

3. Propagating Port Descriptions

In the Designer, in addition to the other properties of port propagation, we can edit a port description and propagate the description to other transformations in the mapping.

4. Environment SQL Enhancements

In PowerCenter 8, environment SQL can be used to execute an SQL statement at the beginning of each transaction. The Integration Service executes transaction environment SQL at the beginning of each transaction. Environment SQL can still be used to execute an SQL statement at each connection to the database.

Use SQL commands that depend upon a transaction being opened during the entire read or write process. For example, the following SQL command modifies how the session handles characters:

ALTER SESSION SET NLS_LENGTH_SEMANTICS=CHAR

5. Flat File Enhancements

PowerCenter 8 includes enhancements for handling flat files. Some of these improve performance.

Flat files can now use Integer or Double data types.

In addition, target partitions can be merged. The flat file target merge options include:

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Informatica PowerCenter 8x Key Concepts -3

dministration Console

The Administration Console is a web application that we use to administer the PowerCenter domain and PowerCenter security. There are two pages in the console, Domain Page & Security Page.
We can do the following In Domain Page:

o Create & manage application services like Integration Service and Repository Service

o Create and manage nodes, licenses and folders

o Restart and shutdown nodes

o View log events

o Other domain management tasks like applying licenses and managing grids and resources

We can do the following in Security Page:

o Create, edit and delete native users and groups

o Configure a connection to an LDAP directory service. Import users and groups from the LDAP directory service

o Create, edit and delete Roles (Roles are collections of privileges)

o Assign roles and privileges to users and groups

o Create, edit, and delete operating system profiles. An operating system profile is a level of security that the Integration Services uses to run workflows

4. PowerCenter Client

Designer, Workflow Manager, Workflow Monitor, Repository Manager & Data Stencil are five client tools that are used to design mappings, Mapplets, create sessions to load data and manage repository.

Mapping is an ETL code pictorially depicting logical data flow from source to target involving transformations of the data. Designer is the tool to create mappings

Designer has five window panes, Source Analyzer, Warehouse Designer, Transformation Developer, Mapping Designer and Mapplet Designer.

Source Analyzer:

Allows us to import Source table metadata from Relational databases, flat files, XML and COBOL files. We can only import the source definition in the source Analyzer and not the source data itself is to be understood. Source Analyzer also allows us to define our own Source data definition.

Warehouse Designer:

Allows us to import target table definitions which could be Relational databases, flat files, XML and COBOL files. We can also create target definitions manually and can group them into folders. There is an option to create the tables physically in the database that we do not have in source analyzer. Warehouse designer doesn’t allow creating two tables with same name even if the columns names under them vary or they are from different databases/schemas.

Transformation Developer:

Transformations like Filters, Lookups, Expressions etc that have scope to be re-used are developed in this pane. Alternatively Transformations developed in Mapping Designer can also be reused by checking the option‘re-use’ and by that it would be displayed under Transformation Developer folders.

Mapping Designer:

This is the place where we actually depict our ETL process; we bring in source definitions, target definitions, transformations like filter, lookup, aggregate and develop a logical ETL program. In this place it is only a logical program because the actual data load can be done only by creating a session and workflow.

Mapplet Designer:

We create a set of transformations to be used and re-used across mappings.

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