title: WCF "Too many active security negotiations" error in production
body: <p>We have a WCF service that over 100 client sites make calls to. Today we started getting the</p>
  
  <pre><code>Exception: Server 'http://[url]/services/[service].svc/ws' sent back a     
  fault indicating it is too busy to process the request. Please retry later. Please see the 
  inner exception for fault details.
  System.ServiceModel.FaultException: There are too many active security negotiations or 
  secure conversations at the service. Please retry later.
  </code></pre>
  
  <p>The only information I could find is that I need to make the <code>maxPendingSessions</code> larger. But that would require changing the endpoint to a CustomBinding, which will be difficult because I'd have to push that to all of my client sites. </p>
  
  <p>Is there some way I can just "reset" the number of security negotiations and such? This would give us time to change the client program to use the custom binding, because at the moment, our sites cannot talk to our server.<br>
  I've tried making a small change to the config file and saving, which should have restarted the service, but we're still getting errors.</p>
  
  <p>Or is there some other way I could handle this?</p>
  
  <p><strong>Edit</strong> Here's my config:</p>
  
  <pre><code>&lt;?xml version="1.0"?&gt;
  &lt;configuration&gt;
    &lt;configSections&gt;
      &lt;section name="dataConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Data.Configuration.DatabaseSettings,     Microsoft.Practices.EnterpriseLibrary.Data"/&gt;
    &lt;/configSections&gt;
    &lt;connectionStrings&gt;
    &lt;/connectionStrings&gt;
      &lt;system.web&gt;
        &lt;compilation debug="true" targetFramework="4.0"/&gt;
        &lt;authorization&gt;
          &lt;allow users="?"/&gt;
        &lt;/authorization&gt;
      &lt;/system.web&gt;
  
    &lt;system.diagnostics&gt;
      &lt;sources&gt;
        &lt;source name="System.ServiceModel" switchValue="Error" propagateActivity="true"&gt;
          &lt;listeners&gt;
            &lt;add name="xml" /&gt;
          &lt;/listeners&gt;
            &lt;/source&gt;
      &lt;/sources&gt;
      &lt;sharedListeners&gt;
        &lt;add name="xml" type="System.Diagnostics.XmlWriterTraceListener" initializeData="D:\logs\log.txt" /&gt;
      &lt;/sharedListeners&gt;
    &lt;/system.diagnostics&gt;
  
    &lt;system.serviceModel&gt;
  &lt;diagnostics performanceCounters="All" /&gt;
          &lt;services&gt;
         &lt;service name="WCFServiceLibrary.WCFService"&gt;
       &lt;endpoint address="ws" binding="wsHttpBinding"     bindingConfiguration="WSHttpBinding_IWCFService"
        name="WSHttpEndpoint_IWCFService" contract="WCFServiceLibrary.IWCFService" /&gt;
       &lt;endpoint address="basic" binding="basicHttpBinding"
                name="BasicHttpEndpoint_IWCFService"             contract="WCFServiceLibrary.IWCFService" /&gt;
       &lt;endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/&gt;
     &lt;/service&gt;
    &lt;/services&gt;
      &lt;bindings&gt;
            &lt;wsHttpBinding&gt;
              &lt;binding name="WSHttpBinding_IWCFService" 
              maxBufferPoolSize="524288" maxReceivedMessageSize="1048576"&gt;
          &lt;readerQuotas maxDepth="32" maxStringContentLength="65536"     maxArrayLength="16384"
              maxBytesPerRead="4096" maxNameTableCharCount="16384" /&gt;
            &lt;security mode="Message"&gt;
              &lt;message clientCredentialType="Certificate"     negotiateServiceCredential="true"
                  algorithmSuite="Default" /&gt;
            &lt;/security&gt;
          &lt;/binding&gt;
        &lt;/wsHttpBinding&gt;
      &lt;/bindings&gt;
          &lt;behaviors&gt;
              &lt;serviceBehaviors&gt;
          &lt;behavior&gt;
            &lt;serviceCredentials&gt;
              &lt;serviceCertificate findValue="CN=[url]" storeLocation="LocalMachine"     storeName="TrustedPeople" /&gt;
              &lt;clientCertificate&gt;
                &lt;authentication revocationMode="NoCheck"     certificateValidationMode="PeerTrust" /&gt;
                  &lt;/clientCertificate&gt;
            &lt;/serviceCredentials&gt;
            &lt;serviceThrottling maxConcurrentCalls ="1001" maxConcurrentSessions="1001"     maxConcurrentInstances="1000" /&gt;
                      &lt;serviceMetadata httpGetEnabled="true"/&gt;
                      &lt;serviceDebug     includeExceptionDetailInFaults="false"/&gt;
                  &lt;/behavior&gt;
              &lt;/serviceBehaviors&gt;
          &lt;/behaviors&gt;
              &lt;serviceHostingEnvironment multipleSiteBindingsEnabled="true"/&gt;
      &lt;/system.serviceModel&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p><strong>EDIT</strong><br>
  We tried an <code>iisreset</code> and even restarted the server and it's still throwing the same error.</p>