/// <summary>
/// Gets a connection from the pool or creates a new one if all current connections are being used at peak access.
/// </summary>
/// <param name="serverName">Name of the PI server for the adapter's PI connection.</param>
/// <param name="userName">Name of the PI user ID for the adapter's PI connection.</param>
/// <param name="password">Password used for the adapter's PI connection.</param>
/// <param name="connectTimeout">Timeout interval (in milliseconds) for the adapter's connection.</param>
/// <returns>A <see cref="PIConnection"/> from the pool.</returns>
/// <exception cref="InvalidOperationException">Failed to get a pooled PI connection.</exception>
public PIConnection GetPooledConnection(string serverName, string userName = null, string password = null, int connectTimeout = PIConnection.DefaultConnectTimeout)
{
PIConnection connection = null;
// We dynamically allocate pooled PI server connections each having a maximum accessibility count.
// PI's threading model can handle many connections each archiving a small volume of points, but
// falls behind under load when archiving a large volume of points from a single connection.
try
{
lock (m_connectionPool)
{
while ((object)connection == null)
{
// Get next connection from the pool with lowest accessibility count
if (m_connectionPool.Count > 0)
{
PIConnection[] availableConnections = m_connectionPool.Where(c => c.AccessCount < m_accessCountPerConnection).ToArray();
if (availableConnections.Length > 0)
{
connection = availableConnections.Aggregate((currentMin, nextItem) => (object)nextItem != null && currentMin.AccessCount < nextItem.AccessCount ? currentMin : nextItem);
}
}
if ((object)connection == null)
{
// Add pooled connections in groups for better distribution
for (int i = 0; i < m_minimumPoolSize; i++)
{
// Create a new connection
connection = new PIConnection
{
ServerName = serverName,
UserName = userName,
Password = password,
ConnectTimeout = connectTimeout
};
// Since PI doesn't detect disconnection until an operation is attempted,
// we must monitor for disconnections from the pooled connections as well
connection.Disconnected += connection_Disconnected;
connection.Open();
// Add the new connection to the server pool
m_connectionPool.Add(connection);
}
}
}
// Increment current connection access count
connection.AccessCount++;
}
}
catch (Exception ex)
{
throw new InvalidOperationException(string.Format("Failed to get a pooled PI connection: {0}", ex.Message), ex);
}
return(connection);
}
/// <summary>
/// Connects to the configured PI server.
/// </summary>
protected override void AttemptConnection()
{
m_processedMappings = 0;
m_processedMeasurements = 0;
m_totalProcessingTime = 0;
m_connection = new PIConnection
{
ServerName = m_serverName,
UserName = m_userName,
Password = m_password,
ConnectTimeout = m_connectTimeout
};
m_connection.Disconnected += m_connection_Disconnected;
m_connection.Open();
m_mappedPIPoints.Clear();
lock (m_pendingMappings)
{
m_pendingMappings.Clear();
}
m_mapRequestQueue.Clear();
m_mapRequestQueue.Start();
m_archiveQueue.Start();
// Kick off meta-data refresh
RefreshMetadata();
}
/// <summary>
/// Connects to the configured PI server.
/// </summary>
protected override void AttemptConnection()
{
m_processedMeasurements = 0;
m_connection = new PIConnection
{
ServerName = m_serverName,
UserName = m_userName,
Password = m_password,
ConnectTimeout = m_connectTimeout
};
m_connection.Open();
}
/// <summary>
/// Connects to the configured PI server.
/// </summary>
protected override void AttemptConnection()
{
m_connection = new PIConnection
{
ServerName = this.ServerName,
UserName = this.UserName,
Password = this.Password,
ConnectTimeout = this.ConnectTimeout
};
m_connection.Disconnected += m_connection_Disconnected;
m_connection.Open();
m_dataPipe = new PIDataPipe(AFDataPipeType.Snapshot);
//m_dataPipe.Subscribe(m_dataUpdateObserver);
if (AutoStart && (object)OutputMeasurements != null && OutputMeasurements.Any())
{
SubscribeToPointUpdates(this.OutputMeasurementKeys());
}
}
/// <summary>
/// Attempts to connect to this <see cref="PIAdapters.PIPBInputAdapter"/>.
/// </summary>
protected override void AttemptConnection()
{
// This adapter is only engaged for history, so we don't process any data unless a temporal constraint is defined
if (this.TemporalConstraintIsDefined())
{
// Turn off read timer if it's active
m_readTimer.Enabled = false;
m_connection = new PIConnection
{
ServerName = m_serverName,
UserName = m_userName,
Password = m_password,
ConnectTimeout = m_connectTimeout
};
m_connection.Open();
// Start the data reader on its own thread so connection attempt can complete in a timely fashion...
ThreadPool.QueueUserWorkItem(StartDataReader);
}
}
