cluster

The cluster property is used to configure a CUE Zipline cluster. It describes the members of the cluster and how they communicate. Clustering is optional. If you only intend to run a single instance of CUE Zipline then the cluster property can be omitted. If you do intend to run a cluster, then each CUE Zipline instance in the cluster must have a similar (but not identical) cluster property definition. In a cluster of two, for example, the instances might have the following cluster definitions:

cluster:
  instance_id: zipline01
  instance_name: Zipline 1
  listen_address: 0.0.0.0:12790
  members:
    - zipline1.myproject.com:12790,zipline2.myproject.com:12790
    - zipline1.myproject.com:12790,zipline2.myproject.com:12790

and:

cluster:
  instance_id: zipline02
  instance_name: Zipline 2
  listen_address: 0.0.0.0:12790
  members:
    - zipline1.myproject.com:12790,zipline2.myproject.com:12790
    - zipline1.myproject.com:12790,zipline2.myproject.com:12790
instance_id (optional)

The internal ID of this CUE Zipline instance. The ID must be unique within the cluster. If not specified then it is set to the value of the ZL_CLUSTER_INSTANCE_ID environment variable. If ZL_CLUSTER_INSTANCE_ID is not set, then it is set to an automatically assigned UUID.

instance_name (optional)

A descriptive name for the cluster instance. If not specified then it is set to the value of the ZL_CLUSTER_INSTANCE_NAME environment variable. If ZL_CLUSTER_INSTANCE_NAME is not set, then it is set to the name of the host.

listen_address (optional)

The network address and port number to listen on for internal communication between CUE Zipline instances. The network address and port number must be accessible to all other instances in the cluster. If not specified then it is set to the value of the ZL_CLUSTER_LISTEN_ADDRESS environment variable. If ZL_CLUSTER_LISTEN_ADDRESS is not set, then it is set to 0.0.0.0:12790, which means "listen on port 12790, on all the host's network interfaces".

members (optional)

An array containing the network address and port number of each instance in the cluster. If not specified then it is set to the value of the ZL_CLUSTER_MEMBERS environment variable. If ZL_CLUSTER_MEMBERS is not set, then it is set to an empty array.

The value of ZL_CLUSTER_MEMBERS must be a comma-separated list of entries. For example: zipline1.myproject.com:12790,zipline2.myproject.com:12790.

If members is undefined or left as an empty array, then CUE Zipline will run as a single instance (always active).