streamtool getzkstate

Usage

getzkstate [--fmt <format-spec>] [-h,--help] [--trace <level>] [-v,--verbose <level>] [--zkconnect {<host>:<port>},... | --embeddedzk]

The streamtool getzkstate command returns the status of the ZooKeeper servers.

Authority

You do not need any authority to run this command.

Description

You can use this command with both the embedded ZooKeeper and external ZooKeeper. It provides more detailed information than the streamtool embeddedzk --status command.

The command lists the overall status of the ZooKeeper ensemble and provides metrics for each of the servers in the ensemble. For example, the output includes the following details for each server:

Status
Specifies the state of the ZooKeeper server. Possible status values include:
Down
Specifies that the server is down.
Latent
Specifies that the server is initializing.
Not serving
Specifies that the server is running but is not yet serving data.
Serving
Specifies that the server is running and serving data.
Mode
Specifies the mode of the ZooKeeper server. Possible mode values include:
Follower
Specifies that the server is a follower in a multi-server ensemble.
Leader
Specifies that the server is the leader in a multi-server ensemble.
Observer
Specifies that the server is an observer in a multi-server ensemble.
Standalone
Specifies that it is a single-server ensemble.
Average, minimum, and maximum latency
Specify the time, in milliseconds, that the server spent receiving and processing requests.
Connection count
Specifies the number of clients that are connected to the ZooKeeper server.
Requests outstanding
Specifies the number of requests that were received but not yet processed.
Version
Specifies the version of ZooKeeper on the server.

If the specified ZooKeeper ensemble is not running, the command fails.

Options

--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.

--fmt <format-spec>
Specifies the presentation format. The command supports the following values:
  • %Mf: Multiline record format. One line per field.
  • %Nf: Name prefixed field table format. One line per host.
  • %Tf: Standard table format, which is the default. One line per host.
-h,--help
Specifies to show the command syntax.
--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.
-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.

Examples

The following command reports the status of the Zookeeper:

[streamtool <bsmith@StreamsDomain.StreamsInstance>] getzkstate  
ZooKeeper ensemble state: UP
Server                    Status  Mode       Average latency Minimum latency Maximum latency ...
host1.teracloud.com:40740 SERVING standalone               0               0             343