streamtool rmhost

Usage

rmhost [-d,--domain-id <did>] [-i,--instance-id <instance>] [--noprompt] [--force] [--continue] [-U,--User <user>] [-h,--help] [--trace <level>] [-v,--verbose <level>] [--zkconnect {<host>:<port>},... | --embeddedzk] <hostname> ... | <hostname>,...

The streamtool rmhost command removes one or more static Streams resources from an instance.

Authority

You must have delete and search authority for the hosts instance object. By default, the DomainAdministrator and InstanceAdministrator roles have this authority. For more information about access control lists, see streamtool getacl.

Description

Before the command removes resources from the instance, it verifies that the instance and the relevant jobs can remain healthy without these resources. If there are any management services on these resources, there must be standby services that are configured and available for the instance to remain healthy. For the jobs to remain healthy, there must be another resource in the instance that meets the placement constraints of all processing elements that are currently running on the resource. This command does not apply to resources that are obtained from an external resource manager.

Resources that are running management services cannot be removed unless standby services are configured and available.

You cannot remove resources that are configured as a result of resource specifications (that is to say, by using the --numresources option). To remove resource specifications from an instance, use the streamtool rmresourcespec command.

The streamtool rmhost command performs a controlled shutdown of the processing elements and host controller service on the resource. The processing elements are relocated. If one or more processing elements cannot be relocated, the command fails.

The resource is removed from the instance's configuration.

If you specify multiple resources in this command, each resource is removed sequentially and independently. If one of the resources cannot be removed, this failure does not affect the removal of other resources.

See also

streamtool quiescehost.

Options

--continue
This option is deprecated and no longer has any effect.
-d,--domain-id <did>
Specifies the domain identifier.

If you do not specify this option, Streams uses the domain name that is set in the STREAMS_DOMAIN_ID environment variable. By default, that domain name is StreamsDomain. If you are using the interactive streamtool interface, it uses the name of the active domain for the current streamtool session or else it prompts you for the domain name.

The active domain for the current streamtool session is set every time that you successfully run a streamtool command with a -d or --domain-id option. Alternatively, you can run the streamtool domain command in the interactive interface.

--embeddedzk

Specifies to use the embedded copy of ZooKeeper. This option is not supported within the interactive streamtool interface.

If you are not using the interactive streamtool interface and you do not specify either this option or the --zkconnect option, Streams uses the ZooKeeper connection that is associated with the active domain or the domain that is specified in the --domain-id option. Streams determines which connection maps to the domain by using cached information about the domains. In this scenario, if the domain identifier is not unique in the Streams configuration cache, the command fails.

--force
This option is deprecated and no longer has any effect.
-h,--help
Specifies to show the command syntax.
-i,--instance-id <instance>
Specifies the instance identifier.

If you do not specify this option, Streams uses the instance identifier that is set in the STREAMS_INSTANCE_ID environment variable. By default, that instance identifier is StreamsInstance. If you are using the interactive streamtool interface, it tries to use an instance ID that you specified in a previous command. If no such value is found, the command uses the STREAMS_INSTANCE_ID environment variable. Alternatively, you can run the streamtool instance command in the interactive interface.

--noprompt
Specifies to suppress confirmation prompts.
--trace <level>
Specifies the trace setting. The following valid levels are listed in order of increasing verbosity, which is to say that the first level in the list generates the least amount of information:
  • off
  • error
  • warn
  • info
  • debug
  • trace
The default value is off.
-U,--User <user>
Specifies an Streams user ID that has authority to run the command.
-v,--verbose <level>
Specifies to provide more detailed command output. The verbosity level can be 0-3, where 0 disables detailed reporting and each increment provides more detailed output.
--zkconnect <{<host>:<port>},...>

The name of one or more host and port pairs that specify the configured ZooKeeper servers. This option is not supported within the interactive streamtool interface.

If you are not using the interactive streamtool interface and you do not specify this option, Streams tries to use:

  1. The --embeddedzk option
  2. The value from the STREAMS_ZKCONNECT environment variable
  3. A ZooKeeper connection string that is derived from cached information about the current domain.

Arguments

hostname
Specifies the host name or IP address for a host in the domain.

Examples

The following example removes the server4 resource from the StreamsInstance instance:

[streamtool <bsmith@StreamsDomain.StreamsInstance>]rmhost server4
CDISC1009W Do you want to remove the resource from the StreamsInstance instance
in the StreamsDomain domain? Enter "y" to continue or "n" to cancel: y
CDISC0045I InfoSphere Streams is removing the following resource from the 
StreamsInstance instance: server4. The instance is in the StreamsDomain domain.