Question

I have a web site that communicates with a .NET 4 WCF web services. That WCF service connects to Dynamics GP Web Services on a remote server. Both Web Services are self-hosted (no IIS).

The first call to GP takes around 12 seconds to complete!! Calls immediately after (even in another WCF request) are around 100ms, but if I wait a minute or two between calls, it will take again 10 seconds…

What could be the cause of the issue, how can I resolve it?

I’ve generated a proxy using both SvcUtil and VS 2010 Add Service Reference, but got the same problem with both. The Dynamics GP proxy file is huge 3MB, don’t know if that’s related.

I ran Wireshark to analyse network traffic and the actual tcp request-reply stream seems to take less than a second. There seems to be something going on before the request is sent that take up that 10 seconds.

Here is the code used:

Context context = new Context();
CompanyKey companyKey = new CompanyKey();
companyKey.Id = -1;
context.OrganizationKey = companyKey;

System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
sw.Start();

_proxy = new DynamicsGPClient();
_proxy.ClientCredentials.Windows.ClientCredential.Domain = Domain;
_proxy.ClientCredentials.Windows.ClientCredential.UserName = Username;
_proxy.ClientCredentials.Windows.ClientCredential.Password = Password;

long openingMs = sw.ElapsedMilliseconds;
CustomerCriteria customerCriteria = new CustomerCriteria();
CustomerSummary[] gpCustomers = _proxy.GetCustomerList(customerCriteria, context);
long fctCallMs = sw.ElapsedMilliseconds;
...
if (_proxy != null && _proxy.State != System.ServiceModel.CommunicationState.Faulted) {
    _proxy.Close();
}

Here’s the app.config:

<system.serviceModel>
   <bindings>
      <wsHttpBinding>
         <binding name="GPWebService" closeTimeout="00:01:00" openTimeout="00:01:00"
                  receiveTimeout="00:10:00" sendTimeout="00:01:00" bypassProxyOnLocal="false" 
                  transactionFlow="false" hostNameComparisonMode="StrongWildcard" 
                  maxBufferPoolSize="2147483647" maxReceivedMessageSize="2147483647" 
                  messageEncoding="Text" textEncoding="utf-8" 
                  useDefaultWebProxy="true" allowCookies="false">
            <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384" 
                          maxBytesPerRead="4096" maxNameTableCharCount="2147483647"/>
            <reliableSession ordered="true" inactivityTimeout="00:10:00" enabled="false"/>
            <security mode="Message">
               <transport clientCredentialType="Windows" proxyCredentialType="None" realm=""/>
               <message clientCredentialType="Windows" negotiateServiceCredential="true" algorithmSuite="Default"/>
            </security>
         </binding>
      </wsHttpBinding>
   </bindings>
   <client>
      <endpoint address="http://192.168.x.y:48620/Dynamics/GPService/GPService" binding="wsHttpBinding"
                bindingConfiguration="GPWebService"
                contract="DynamicsGpService.DynamicsGP" name="GPWebService">
         <identity>
            <userPrincipalName value="DEV\gpeconnect"/>
         </identity>
      </endpoint>
   </client>
</system.serviceModel>

Answer 1

Self answer

For the community, here’s what I have found out (but I can’t explain why, so don’t ask! ;))

In the Client’s app.config, useDefaultWebProxy="true" should be set to false… this made a very simple Hello World Web Service pass from 7 sec to ~100ms on the first call.

In the Client’s app.config, completely removing the identity > userPrincipalName section caused the first WCF call to pass from > 10 sec to ~1 sec!