Informatica: PowerCenter

It has a service oriented architecture that provides ability to scale services and share resources across multiple machines.

+ Domain:

+  Nodes:

         + Gateway Nodes

       + Worker Nodes

   + Services:

         + Service Manager:

             + Application Service Support:

             + Domain function:

                   + Alerts:

                   + Domain Configuration:

                   + Node Configuration:

                   + Logging:

         + Application Services:

             + Repository Services: Store metadata in repository tables.

             + Integration Services

             + Web Services HUB: Receives requests from web services clients and initiates PowerCenter workflows as response.

             + SAP BW Service: RFC request from SAP BW and initiates workflow to extract from or load to SAP BW.

Services can run on multiple nodes.  Node failover is implemented in Informatica via alerts.

INTEGRATION SERVICES:

Overview: It runs sessions and workflows.

LOAD BALANCER:

It matches the task requirement with resource availability to identify the best integration service processes running on nodes in a grid.

+ Dispatch mode

+ round-robin

+ round-robin with load metrics

+ node with most available resources

+ Service level

+ Establishes priority for a task that is waiting to be dispatched.

Load Balancer Setting on each node:

+ Resources: Compare available resources with required resources by the task.

+ CPU profile: computing throughput of each CPU and bus architecture.

+ Resource provision threshold: 

+ Maximum processes threshold

Distributed transaction

In distributed transaction, you may commit only from the site from where transaction began.  This implies you cannot execute DDL over dblink since that DDL cause implicit commit.

2 PC commit: 

1.  Driving Site asks secondary databases participating in transaction to prepare for commit.  All participating databases send the message back that they are ready to commit.

2.  Primary site sends broadcast message to all of them to commit.

To do DDL over the remote site, Oracle can use DBMS_JOB to schedule a job to do DDL on the remote site via db link.