public async Task Should_Not_Use_The_LoadBalancingPolicy_When_Targeting_Single_Host()
{
var queryPlanCounter = 0;
var lbp = new TestHelper.CustomLoadBalancingPolicy((cluster, ks, stmt) =>
{
Interlocked.Increment(ref queryPlanCounter);
return(cluster.AllHosts());
});
var builder = Cluster.Builder().WithLoadBalancingPolicy(lbp);
using (var testCluster = SimulacronCluster.CreateNew(new SimulacronOptions {
Nodes = "3"
}))
using (var cluster = builder.AddContactPoint(testCluster.InitialContactPoint).Build())
{
var session = await cluster.ConnectAsync();
var host = cluster.AllHosts().Last();
Interlocked.Exchange(ref queryPlanCounter, 0);
await TestHelper.TimesLimit(() =>
{
var statement = new SimpleStatement("SELECT * FROM system.local").SetHost(host);
return(session.ExecuteAsync(statement));
}, 1, 1);
Assert.Zero(Volatile.Read(ref queryPlanCounter));
}
}
public void Should_Throw_NoHostAvailableException_When_Targeting_Single_Ignored_Host()
{
const string query = "SELECT * FROM system.local";
// Mark the last host as ignored
var lbp = new TestHelper.CustomLoadBalancingPolicy(
(cluster, ks, stmt) => cluster.AllHosts(),
(cluster, host) => host.Equals(cluster.AllHosts().Last()) ? HostDistance.Ignored : HostDistance.Local);
var builder = Cluster.Builder().WithLoadBalancingPolicy(lbp);
using (var testCluster = SimulacronCluster.CreateNew(new SimulacronOptions {
Nodes = "3"
}))
using (var cluster = builder.AddContactPoint(testCluster.InitialContactPoint).Build())
{
var session = cluster.Connect();
var lastHost = cluster.AllHosts().Last();
// Use the last host
var statement = new SimpleStatement(query).SetHost(lastHost);
Parallel.For(0, 10, _ =>
{
var ex = Assert.ThrowsAsync <NoHostAvailableException>(() => session.ExecuteAsync(statement));
Assert.That(ex.Errors.Count, Is.EqualTo(1));
Assert.That(ex.Errors.First().Key, Is.EqualTo(lastHost.Address));
});
}
}