Socket connection aborted using NetTcpBinding

Question

I know there are quite some questions about this issue already, but no reply solved my problem.

I have a NetTcpBinding on a server running, and from time to time (not always, like 1 out of 20 to 60 calls, completely random) I receive this exception on the client side:

The socket connection was aborted. This could be caused by an error processing your message or a receive timeout being exceeded by the remote host, or an underlying network resource issue. Local socket timeout was '00:01:00'.

I noticed that this exceptions occurs much more frequently when the client's connection is slow.

Also, the timeout stated is 1 minute, but the exception already occurs after 1 second or so.

What I do:

var client = GetClient();
client.Open();
bool success = client.Call(); // Exception occurs here (the return value is a bool)

I sometimes also get this exception on the server side:

A TCP error (995: The I/O operation has been aborted because of either a thread exit or an application request) occurred while transmitting data.

I have server tracing enabled but I get the same exceptions, and it doesn't provide me with any additional insight.

My GetClient:

NetTcpBinding netTcpBinding = new NetTcpBinding
{
    CloseTimeout = new TimeSpan(0, 0, 30),
    OpenTimeout = new TimeSpan(0, 0, 30),
    TransferMode = TransferMode.Buffered,
    ListenBacklog = 2,
    MaxConnections = 2,
    MaxReceivedMessageSize = 10485600,
    ReaderQuotas = { MaxStringContentLength = 1048576 },
    ReliableSession = { Enabled = false },
    Security =
    {
        Mode = SecurityMode.Transport,
        Transport = { ClientCredentialType = TcpClientCredentialType.None, ProtectionLevel = ProtectionLevel.EncryptAndSign },
        Message = { ClientCredentialType = MessageCredentialType.Windows }
    }
};

Important config from service:

<behaviors>
    <serviceBehaviors>
        <behavior name="ServiceBehavior">
            <serviceMetadata httpGetEnabled="true" /> 
            <serviceDebug includeExceptionDetailInFaults="true" httpHelpPageEnabled="true" httpsHelpPageEnabled="true" />
            <serviceAuthorization principalPermissionMode="Custom" serviceAuthorizationManagerType="My.Service.WCF.Tools.CustomAuthorizationManager, My.Service.WCF">
                <authorizationPolicies>
                    <clear/>
                    <add policyType="My.Service.WCF.Tools.CustomAuthorizationPolicy, My.Service.WCF" />
                </authorizationPolicies>
            </serviceAuthorization>
            <serviceCredentials>
                <serviceCertificate findValue="MyService" storeLocation="LocalMachine" storeName="My" x509FindType="FindBySubjectName" />
            </serviceCredentials>
            <serviceThrottling maxConcurrentCalls="65536" maxConcurrentSessions="65536" maxConcurrentInstances="65536" />
        </behavior>
    </serviceBehaviors>
</behaviors>
<bindings>
    <customBinding>
        <binding name="ServiceBinding" receiveTimeout="00:05:00" maxConnections="65536" listenBacklog="65536">
            <transactionFlow />                      
            <sslStreamSecurity requireClientCertificate="false" />
            <binaryMessageEncoding />
            <tcpTransport transferMode="Buffered" portSharingEnabled="true" maxReceivedMessageSize="1048576" maxPendingConnections="65536" maxPendingAccepts="10">
                <connectionPoolSettings leaseTimeout="00:05:00" idleTimeout="00:05:00" maxOutboundConnectionsPerEndpoint="65536" />
            </tcpTransport>
        </binding>
        <binding name="MexBinding" receiveTimeout="00:05:00" maxConnections="65536" listenBacklog="65536"> 
            <tcpTransport transferMode="Buffered" portSharingEnabled="true" maxReceivedMessageSize="1048576" maxPendingConnections="65536" maxPendingAccepts="10">
                <connectionPoolSettings leaseTimeout="00:05:00" idleTimeout="00:05:00" maxOutboundConnectionsPerEndpoint="65536" />
            </tcpTransport>
        </binding>
    </customBinding>
</bindings>

I have already updated service reference and tried to change some of the buffer and sizes, but it didn't work (not that I'd expect an issue there as only a bool is returned).

Fixed using:

OperationContext.Current.OperationCompleted += Test;

private void Test(object sender, EventArgs e)
{
    OperationContext.Current.Channel.Close();
}

Do not use the Abort but the Close method!

Answer 1

I found the problem: I aborted the channel on server side with

OperationContext.Current.OperationCompleted

which called:

OperationContext.Current.Channel.Abort();

This seems to work fine in 99% of the cases, but not all, using:

OperationContext.Current.Channel.Close();

resolved my problem completely.