Domain and instance services

When you start a Teracloud® Streams domain, instance, or stream 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, rest, sws, or view).

Domain services

The following services are domain services:

Table 1. Domain services
This table lists and describes domain services in Teracloud® Streams, and includes a list of tags for these services to run on specific resources. The table also indicates short names used for each service in Teracloud® Streams messages and commands.
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 a Teracloud® 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 Teracloud® 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`.
JMX management API service	The JMX management API service is a management service that provides an application programming interface (API). The Streams Console uses this API to obtain information about the domain. There can be only one JMX 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`.
REST management API service	The REST management API service is a management service that provides an application programming interface (API). It is based on the Representational State Transfer (REST) architectural principles and is implemented by using the HTTP protocol. You can use this API to monitor and manage Streams services and jobs. There can be only one REST management API service per resource. If you want this service to run on specific resources, use the following tags: rest. The following short name is used for this service in messages and commands: `rest`.
web management service	The web management service is a management service that provides web-based access to monitor and manage domain services, instance services, and jobs. 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:

Table 2. Instance services
This table lists and describes instance services in Teracloud® Streams, and includes a list of tags for these services to run on specific resources. The table also indicates short names used for each service in Teracloud® Streams messages and commands.
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 includes a 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 collects runtime metrics for Streams jobs, resources and 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`.
data service	The data service is a management service that provides an application programming interface (API) to determine the endpoints available for transferring data to and from Streams jobs. You can also use the data service to invoke the endpoints to inject data into jobs and to inspect data flowing through jobs. There can be only one data service per resource. If you want this service to run on specific resources, use the data tag. The following short name is used for this service in messages and commands: `data`.
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 (PEC), 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 or a table. 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`.