Domain and instance services
When you start an IBM® Streams domain, instance, or stream processing application, services start on the appropriate resources.
You can manage which services run on specific resources by using tags. For example, you can apply the application tag to a resource so that it runs the application services. Likewise, you can apply the management tag to a resource so that it runs the domain and instance management services. If you prefer to run specific management services on specific resources, use the appropriate tag for that service (for example, authentication, audit, jmx, sws, or view).
Domain services
The following services are domain services:| Domain service | Description |
|---|---|
| authentication and authorization service | The authentication and authorization service is a management service that authenticates and authorizes operations for the domain and all of
the instances in the domain. If you want this service to run on specific resources, use the following tags: authentication. The following short name is used for this service in messages and commands: aas. |
| domain controller service | A domain controller service runs on every resource in an
IBM
Streams domain and
manages all of the other services on that resource. This service starts when you configure the resource in the domain, or when you run the streamtool registerdomainhost or streamtool startdomainhost command. This service is not associated with any tags. For more information, see Options for setting up the domain controller service on resources. The following short name is used for this service in messages and commands: controller. |
| logging service | The logging service is a management service that has two functions. It writes user messages in the
streams.0.log file.
It
is also involved in audit logging. For more information, see Audit logging support for IBM
Streams. If you want this service to run on specific resources, use the following tags: audit. The following short name is used for this service in messages and commands: auditlog. |
| management API service | The management API service is a management service that provides an application programming interface (API). The Streams
Console and Streams Studio use this API to obtain information about the domain. There can be only one management API service per resource. If you want this service to run on specific resources, use the following tags: jmx. The following short name is used for this service in messages and commands: jmx. |
| web management service | The web management service is a management service that provides web-based access to instance services. There is only one
web management service in a domain. If you want this service to run on specific resources, use the following tag: sws. The following short name is used for this service in messages and commands: sws. |
Instance services
The following services are instance services:| Instance service | Description |
|---|---|
| application deployment service | The application
deployment service is an application service that prepares application resources for deploying and running
processing elements. It manages the deployment of application bundles to the appropriate resources.
If you want this service to run on specific resources, use the application tag. This service runs on every application resource in the instance. The following short name is used for this service in messages and commands: app. |
| application manager service | The application manager service is a management service that administers the applications in the instance. This service handles
job management tasks, including user requests such as job submission and cancellation. It interacts
with the scheduler to compute the placement of processing elements that are associated with an
application. It also interacts with the domain controller service to deploy and cancel the execution of these processing elements. If you want this service to run on specific resources, use the management tag. The following short name is used for this service in messages and commands: sam. |
| application metrics service | The application metrics service is a management service that initializes the IBM
Streams instance and monitors all instance services. The application metrics service collects run time metrics on the resources and IBM
Streams components. This service also collects performance metrics that are necessary for scheduling and
system administration by interacting with the domain controller service. If you want this service to run on specific resources, use the management tag. The following short name is used for this service in messages and commands: srm. |
| Processing elements (PEs) and processing element container services (PEC) | Streams Processing Language (SPL) programs consist of operators, which are grouped at compile
time into partitions. The execution container for a partition is a processing element (PE). Each
partition runs in one PE. PEs are loaded by the processing element container service, which is started and monitored by the domain controller service for the resource that the PE is running on. If you want this service to run on specific resources, use the application tag. |
| view service | The view service is a management service that administers the data that is used in views. A view defines the set
of attributes that can be displayed in a chart, table, or Microsoft Excel. For more information, see Views, charts, and tables.
If there are many data visualization users in your instance, consider running this service on a
separate resource from other management services. If you want this service to run on specific resources, use the view tag. The following short name is used for this service in messages and commands: view. |