vertx-ext-cassandra

Apache Cassandra integration for Vert.x 3.x

Intro

This extension provides functionality to access a Cassandra database with Vert.x 3.x using a Verticle Service Factory. The code is heavily borrowed from the folks at englishtown and nea, as they both have done awesome work for Vert.x 2.x.

Configuration

The configuration follows mostly from vertx-mod-cassandra from englishtown, with elements from nea. The following options are available:

{
    "cassandra": {
        "seeds": [<seeds>],
        
        "policies": {
            "load_balancing": {
                "name": "<lb_policy_name>",
            },
            "reconnect_policy": {
                "name": "<reconnect_policy_name>"
            }
        },
        
        "pooling": {
            "core_connections_per_host_local": <int>,
            "core_connections_per_host_remote": <int>,
            "max_connections_per_host_local": <int>,
            "max_connections_per_host_remote": <int>,
            "min_simultaneous_requests_local": <int>,
            "min_simultaneous_requests_remote": <int>,
            "max_simultaneous_requests_local": <int>,
            "max_simultaneous_requests_remote": <int>
        },
        
        "socket": {
            "connect_timeout_millis": <int>,
            "read_timeout_millis": <int>,
            "keep_alive": <boolean>,
            "reuse_address": <boolean>,
            "receive_buffer_size": <int>,
            "send_buffer_size": <int>,
            "so_linger": <int>,
            "tcp_no_delay": <boolean>
        }
    }
}

• seeds - an array of string seed IP or host names. At least one seed must be provided.
• lb_policy_name - (optional) the load balancing policy name. The following values are accepted:
  • "DCAwareRoundRobinPolicy" - requires string field local_dc and optional numeric field used_hosts_per_remote_dc
  • Any FQCN such of a class that implements LoadBalancingPolicy
• reconnect_policy_name - (optional) the reconnect policy name. The following values are accepted:
  • "constant"|"ConstantReconnectionPolicy" - creates a ConstantReconnectionPolicy policy. Expects additional numeric field delay in ms.
  • "exponential"|"ExponentialReconnectionPolicy" - creates an ExponentialReconnectionPolicy policy. Expects additional numeric fields base_delay and max_delay in ms.

Refer to the Cassandra Java driver documentation for a description of the remaining configuration options.

A sample config looks like:

{
    "cassandra": {
        "seeds": ["10.0.0.1", "10.0.0.2"],
        
        "policies": {
            "load_balancing": {
                "name": "DCAwareRoundRobinPolicy",
                "local_dc": "LOCAL1",
                "used_hosts_per_remote_dc": 1
            },
            "reconnect": {
                "name": "exponential",
                "base_delay": 1000,
                "max_delay": 10000
            }
        },
    }
}

Overriding with Environment Variables

This is not yet supported in ext-cassandra.

Defaults

If there is no configuration, neither JSON nor environment variables, the module will default to looking for cassandra at 127.0.0.1 with the Cassandra driver defaults for everything.