WCF rest hosting on IIS - wcf

Question

I have an wcf rest service. I hosted it in IIS with following service configuration
<system.serviceModel>
<services>
<service behaviorConfiguration="Default" name="CRM_Service.CRM_Service">
<endpoint address="" behaviorConfiguration="webBehavior"
binding="webHttpBinding" bindingConfiguration="webHttpBinding_ICRM_Service" contract="CRM_Service.ICRM_Service" />
<endpoint contract="IMetadataExchange" binding="mexHttpBinding" address="mex" />
<host>
<baseAddresses>
<add baseAddress="*********" />
</baseAddresses>
</host>
</service>
</services>
<bindings>
<webHttpBinding>
<binding name="webHttpBinding_ICRM_Service" closeTimeout="00:04:00" maxReceivedMessageSize="2147483647"
maxBufferPoolSize="2147483647">
<readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647"
maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647" />
</binding>
</webHttpBinding>
</bindings>
<behaviors>
<endpointBehaviors>
<behavior name="webBehavior">
<webHttp />
</behavior>
</endpointBehaviors>
<serviceBehaviors>
<behavior name="Default">
<serviceMetadata httpGetEnabled="true" />
<serviceDebug includeExceptionDetailInFaults="true" />
<serviceThrottling maxConcurrentCalls="500" maxConcurrentSessions="500"
maxConcurrentInstances="500" />
</behavior>
<behavior name="">
<serviceMetadata httpGetEnabled="true" />
<serviceDebug includeExceptionDetailInFaults="false" />
</behavior>
</serviceBehaviors>
</behaviors>
<serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
<diagnostics>
<messageLogging logEntireMessage="true"
logMessagesAtServiceLevel="false"
logMessagesAtTransportLevel="false"
logMalformedMessages="true"
maxMessagesToLog="5000"
maxSizeOfMessageToLog="2000">
</messageLogging>
</diagnostics>
</system.serviceModel>
I used separate application pool for this project. After hosting it worked fine for some duration,but after that service was not responding for any method call. Please help me to come out this issue. Thanks in advance...