I have a C# WebService setup to return JSON info for use on a mobile. Everything is working fine, except one of the calls which now throws an “HTTP Error 502 (Bad Gateway): The gateway or proxy server received an invalid response from an upstream server”.
The error started when I increased the data the call returned. The data is read from a JSON file residing on the server. The size of this data file was previously 1,324,859 bytes which worked fine (and still does), the new data file is 1,563,570 bytes and this is the one failing.
It seems pretty obvious that I hit some sort of default limit to how much I can return in a single call, but I cannot for the like of me figure out how to increase this limit. Googling points in the direction of setting maxJsonLength, but this doesn’t seem to have any effect.
Below is the drilled down code for the WebService and more importantly my web.config. I should say that the call is working fine locally, meaning while running in VS2010, but failing on the server (GearHost running IIS 7.5).
I am quite a novice in configuring/setting up IIS, so any help is greatly appreciated.
[ServiceContract]
public interface IMyService
{
[OperationContract]
[WebInvoke(Method = "GET", UriTemplate = "/GetItems", RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json)]
Item[] GetItems();
}
public class MyService : IMyService
{
public Item[] GetItems()
{
var result = ReadDataFile<List<Item>>(DataType.Items);
return result == null ? null : result.ToArray();
}
}
I have tried so many settings by now, that I am not even sure what needs to be in here and what shouldn’t…
<?xml version="1.0"?>
<configuration>
<configSections>
<sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
<sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
<section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
<sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
<section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="Everywhere" />
<section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" />
<section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" />
<section name="roleService" type="System.Web.Configuration.ScriptingRoleServiceSection, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" />
</sectionGroup>
</sectionGroup>
</sectionGroup>
</configSections>
<system.web>
<customErrors mode="On"/>
<compilation debug="true" targetFramework="4.0" />
<caching>
<outputCacheSettings>
<outputCacheProfiles>
<add name="NoCacheProfile" noStore="true" duration="0" varyByParam="none" enabled="true"/>
</outputCacheProfiles>
</outputCacheSettings>
</caching>
</system.web>
<system.serviceModel>
<bindings>
<webHttpBinding>
<binding name="StreamedRequestWebBinding"
bypassProxyOnLocal="true"
useDefaultWebProxy="false"
hostNameComparisonMode="WeakWildcard"
sendTimeout="10:15:00"
openTimeout="10:15:00"
receiveTimeout="10:15:00"
maxReceivedMessageSize="2147483647"
maxBufferSize="2147483647"
maxBufferPoolSize="2147483647"
transferMode="StreamedRequest">
<readerQuotas maxArrayLength="2147483647"
maxStringContentLength="2147483647" />
</binding>
</webHttpBinding>
</bindings>
<services>
<service name="JSON_WebService.WoWService" behaviorConfiguration="ServiceBehaviour">
<endpoint address ="" binding="webHttpBinding" bindingConfiguration="StreamedRequestWebBinding" contract="JSON_WebService.IWoWService" behaviorConfiguration="web">
</endpoint>
</service>
</services>
<behaviors>
<serviceBehaviors>
<behavior name="ServiceBehaviour">
<serviceMetadata httpGetEnabled="true"/>
<serviceDebug includeExceptionDetailInFaults="false"/>
</behavior>
</serviceBehaviors>
<endpointBehaviors>
<behavior name="web">
<webHttp/>
</behavior>
</endpointBehaviors>
</behaviors>
<serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
</system.serviceModel>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true"/>
</system.webServer>
<system.web.extensions>
<scripting>
<webServices>
<jsonSerialization maxJsonLength="50000000"/>
</webServices>
</scripting>
</system.web.extensions>
</configuration>
After communicating back and forth with GearHost (the ones hosting the web service), they have confirmed that my problem is related to a server error and not a programming/web.config error.
The jsonSerialization setting should have been sufficient.
In their defense I must say that their support is really quite excellent and I think quite a few others would have dismissed my claim as being a development problem.