Examples of com.datastax.driver.core.policies.LoadBalancingPolicy.distance()

com.datastax.driver.core.policies.LoadBalancingPolicy.distance()

Returns the distance assigned by this policy to the provided host.

The distance of an host influence how much connections are kept to the node (see {@link HostDistance}). A policy should assign a {@code LOCAL} distance to nodes that are susceptible to be returned first by{@code newQueryPlan} and it is useless for {@code newQueryPlan} toreturn hosts to which it assigns an {@code IGNORED} distance.

The host distance is primarily used to prevent keeping too many connections to host in remote datacenters when the policy itself always picks host in the local datacenter first. @param host the host of which to return the distance of. @return the HostDistance to {@code host}.

        return this;
    }


    public HostAssert isAtDistance(HostDistance expected) {
        LoadBalancingPolicy loadBalancingPolicy = cluster.manager.loadBalancingPolicy();
        assertThat(loadBalancingPolicy.distance(actual)).isEqualTo(expected);
        return this;
    }


    public HostAssert comesUpWithin(long duration, TimeUnit unit) {
        final CountDownLatch upSignal = new CountDownLatch(1);

        LoadBalancingPolicy lbPolicy = session.getCluster().getConfiguration().getPolicies().getLoadBalancingPolicy();
        String dc = null;
        int count = 0;


        for (Host host : metadata.getAllHosts()) {
            if (lbPolicy.distance(host) == HostDistance.LOCAL) {
                dc = host.getDatacenter();
                count++;
            }
        }

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