Service Instances

When you create a service, you must specify how many instances of the service are allowed to run at the same time.

Since each instance can service one job (or Program or Business Area definition) at a time, this effectively defines the number of jobs that can run on a particular service at a particular time.

For processing engine service types, service instances serve as the interface between the requested job and the Oracle Life Sciences Data Hub execution system. They track the association of a particular job to a particular service and manage many aspects of the job's execution.

IDE service instances control the association between the use of a particular IDE for a particular Program or Business Area (which are used for visualizations) and the security and data access needed by the particular IDE. When a user launches an IDE from the Program or Business Area user interface, the system assigns a service instance to the Program or Business Area. After a service instance is allocated, it remains assigned to that Program or Business Area until it is explicitly released by a Checkin or Undo Checkout.

You can modify the number of service instances for each service.

Note:

For the OBIEE IDE Service, specify a number of Service Instances equal to the maximum number of users you expect to query the repository at the same time, plus a buffer.

If you do not create enough service instances, users may lose access to the database in the middle of a task. For example, if you define 10 service instances and 11 people log in to the same OBIEE URL, when the last person logs in, the system looks for a session that has been running longer than the defined Reuse Wait time for the service. If there is such a session, the system recycles it even if the user is active, and the original user loses his or her connection to the database.

It is better to solve this problem by defining a large number of service instances than a high reuse wait time because the same user cannot open a new session—for example, if he or she wants to select different launch settings—until his or her original session reaches the reuse wait time.