Tableau Server Coordination Service
The Coordination Service is built on Apache ZooKeeper(Link opens in a new window), an open-source project, and coordinates activities on the server, guaranteeing a quorum in the event of a failure, and serving as the source of "truth" regarding the server topology, configuration, and state. The service is installed automatically on the initial Tableau Server node, but no additional instances are installed as you add additional nodes. Because the successful functioning of Tableau Server depends on a properly functioning Coordination Service, we recommend that for server installations of three or more nodes, you add additional instances of the Coordination Service by deploying a new Coordination Service ensemble. This provides redundancy and improved availability in the event that one instance of the Coordination Service has problems.
The hardware for your cluster can have some effect on how well the Coordination Service runs. In particular:
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Memory. The Coordination Service maintains state information in memory. By design, the memory footprint is small, and is typically not a factor in overall server performance.
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Disk speed. Because the service stores state information on disk, it benefits from fast disk speed on the individual node computers.
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Connection speed between nodes. The service communicates continuously between cluster nodes; a fast connection speeds between nodes helps with efficient synchronization.
| Process |
|
| Status | Status of the |
| Logging | Logs generated by the the |
Configuration for the Coordination Service
The Coordination Service is installed automatically on the initial node of Tableau Server. If you are running a single-node installation, you do not need to do anything to deploy or configure the Coordination Service. If your installation includes three or more nodes, you'll be prompted to configure a Coordination Service ensemble when you add your third node. This is not required, but is highly recommended as the Coordination Service serves a key function for high availability, acting as the source of "truth" about server topology, configuration, and state.
To configure a Coordination Service ensemble, use the TSM CLI and add the Coordination Service to the nodes you want running it. For details on how to deploy a Coordination Service ensemble, see Deploy a Coordination Service Ensemble .
The Coordination Service Quorum
To ensure that the Coordination Service can work properly, the service requires a quorum—a minimum number of instances of the service. This means that the number of nodes in your installation impacts how many instances of the Coordination Service you want to configure in your ensemble.
Number of Coordination Service instances to use
The maximum number of Coordination Service instances you can have in an ensemble on Tableau Server depends on how many Tableau Server nodes you have in your deployment. Configure a Coordination Service ensemble based on these guidelines:
| Total number of server nodes | Recommended number of Coordination Service nodes in ensemble (must be 1, 3, or 5) | Notes |
|---|---|---|
| 1-2 nodes | 1 node | This is the default and requires no changes unless you want to move the Coordination Service off your initial node and onto your additional node. |
| 3-4 nodes | 3 nodes | |
| 5 or more nodes | 3 nodes or 5 nodes |
Five is the maximum number of Coordination Service instances you can install. A 3-node Coordination Service ensemble allows for one of the ensemble nodes to fail without causing Tableau Server to fail. A 5-node ensemble allows for two of the ensemble nodes to fail without causing Tableau Server to fail. For most installations, three Coordination Service nodes are adequate, and because of the I/O-intensive nature of the Coordination Service, this is the most performant configuration. If high availability is your absolute priority, you may want to consider deploying a 5-node Coordination Service ensemble. This provides the most redundancy in the event that one or more nodes fail but will require more system resources. A maximum of two of the ensemble nodes can fail without impacting Tableau Server (as long as any other services on the node also exist on still-functioning nodes). To reduce performance impact, locate the Coordination Service on nodes that are running fewer other services or consider using Coordination Service-only nodes. For details, see Configure Tableau Server for High Availability with Coordination Service-Only Nodes. |
If you reduce the number of nodes
If you reduce the nodes in your cluster from three (or more) to two nodes, a warning tells you Tableau Server can no longer support high availability:
A minimum of three Tableau Server nodes are required for high availability. You can add a third node now, or continue with only two nodes. Continuing with only two nodes means Tableau Server will not be highly available. You can always add a third node later. Click OK to continue with 2 nodes, or Cancel to go back and add a node.
If you continue, Tableau Server will run, but you will not have any automatic failover of the repository.
Viewing Coordination Service Status
The Coordination Service is not included in the listing when you View Server Process Status. To see the state of the service, you can use the tsm status command:
tsm status -v
The output from the command shows you whether the service is running:
node1: TABLEAUSVR01
Status: RUNNING
'Tableau Server Gateway 0' is running.
'Tableau Server Application Server 0' is running.
'Tableau Server VizQL Server 0' is running.
'Tableau Server VizQL Server 1' is running.
'Tableau Server VizQL Server 2' is running.
'Tableau Server VizQL Server 3' is running.
'Tableau Server Cache Server 0' is running.
'Tableau Server Cache Server 1' is running.
'Tableau Server Coordination Service 0' is running.
'Tableau Server Cluster Controller 0' is running.
'Tableau Server Search And Browse 0' is running.
'Tableau Server Backgrounder 0' is running.
'Tableau Server Backgrounder 1' is running.
'Tableau Server Data Server 0' is running.
'Tableau Server Data Server 1' is running.
'Tableau Server Data Engine 0' is running.
'Tableau Server File Store 0' is running.
'Tableau Server Repository 0' is running (Active Repository).
'Tableau Server Administration Agent 0' is running.
'Tableau Server Administration Controller 0' is running.
'Tableau Server Service Manager 0' is running.
'Tableau Server License Manager 0' is running.
'Tableau Server Client File Service 0' is running.
'Tableau Server Database Maintenance 0' is stopped.
'Tableau Server Backup/Restore 0' is stopped.
'Tableau Server Site Import/Export 0' is stopped.
'Tableau Server SAML Service 0' is stopped.