/// <summary>
/// Creates a new single-node connection. Internal usage only (Factory pattern on the base class).
/// </summary>
/// <param name="settings">Connection settings to use to connect to the node.</param>
/// <param name="callbackExecutor">The callback executor provided by the factory creator that will execute all
/// callbacks</param>
internal VoltNodeConnection(ConnectionSettings settings, CallbackExecutor callbackExecutor)
: base(settings)
{
this.ExecutionCache = new ExecutionCache(settings.MaxOutstandingTxns);
// Reference to the global callback executor
this.CallbackExecutor = callbackExecutor;
}
/// <summary>
/// Creates a new cluster connection (load-balanced multi-node connection).
/// Internal usage only (Factory pattern on the base class).
/// </summary>
/// <param name="settings">Connection settings to use to connect to the cluster.</param>
/// <param name="callbackExecutor">Reference to the executor that will execute all callbacks.</param>
internal VoltClusterConnection(ConnectionSettings settings, CallbackExecutor callbackExecutor)
: base(settings)
{
// Faster than looking up the settings property all the time
this.LoadBalancingBatchSize = this.Settings.LoadBalancingBatchSize;
// Reference to the global callback executor
this.CallbackExecutor = callbackExecutor;
}
/// <summary>
/// Builds a connection for the given settings. If the settings point to a single server, a VoltNodeConnection
/// is returned. If the settings point to multiple servers, a VoltClusterConnection is returned. Both
/// connection types offer identical signatures, tagged on the base VoltConnection class. The only difference
/// is that the VoltClusterConnection will embed automatic validation that all connected nodes belong to the
/// same cluster, pointing to the same catalog, and perform load balancing between the different servers.
/// Transparently, the Cluster connection will aggregate statistics accross all connections, defer Trace events
/// to each sub-Node connection and perform Round-Robin load balancing (for now this is the only algorithm)
/// between them for actual execution. The cluster connection offers additional control over its behavior upon
/// a node failure (should the conection be re-established, etc.) through the connection settings.
/// </summary>
/// <param name="settings">Connection settings to use to establish the connection.</param>
/// <returns>A VoltConnection object (either a single-node VoltNodeConnection or pooled
/// VoltClusterConnection.</returns>
public static VoltConnection Create(ConnectionSettings settings)
{
CallbackExecutor callbackExecutor = new CallbackExecutor();
switch (settings.HostAddresses.Length)
{
case 0:
throw new ArgumentException(
string.Format(
Resources.InvalidConnectionStringHostList
, settings.HostList
)
);
case 1:
return(new VoltNodeConnection(settings, callbackExecutor, true));
default:
return(new VoltClusterConnection(settings, callbackExecutor));
}
}
/// <summary>
/// Creates a new single-node connection. Internal usage only (Factory pattern on the base class).
/// </summary>
/// <param name="settings">Connection settings to use to connect to the node.</param>
/// <param name="callbackExecutor">The callback executor provided by the factory creator that will execute all
/// callbacks</param>
/// <param name="ownsCallbackExecutor">Flag indicating this connection owns the callback executor and should
/// stop it when it terminates.</param>
internal VoltNodeConnection(ConnectionSettings settings, CallbackExecutor callbackExecutor, bool ownsCallbackExecutor)
: this(settings, callbackExecutor)
{
this.OwnsCallbackExecutor = ownsCallbackExecutor;
}
