URGENT: LOAD.ASHX CAUSES MAJOR ISSUES WITH LOAD BALANCER

Last post 01-19-2012, 7:10 PM by cutechat. 10 replies.
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  •  01-09-2012, 7:31 AM 72561

    URGENT: LOAD.ASHX CAUSES MAJOR ISSUES WITH LOAD BALANCER

    We run our dotnet solution using cutesoft in a load balanced configuration employing the use of an f5 load balancer network appliance.

    We recently upgraded to the 11-10-2011 build when we started experiencing problems experienced MAJOR problems with load.ashx not being properly returned to the client.  I upgraded this evening to the 12-20-2011 build of cutesoft editor, and the problem still persists.

    The resulting adverse behavior was that requests for resources through load.ashx were not received by the client, as a result of the load balancer aborting the request.

    Failures resulted from the failure of delivery of

    • Graphics files
    • Javascript files (disastrous implications)
    • css files

     As you can see – this affects pretty much all the content served through load.ashx, and is critical to the operation of cuteeditor on the client.

     Any failure to deliver content results in a completely unusable and unreliable HTML editor.

     We looked at our load balancer logs and noticed specific errors that are detailed here:

    http://support.f5.com/kb/en-us/solutions/public/5000/900/sol5922.html?sr=14345402

     Of note:

    Any response that is not compliant with RFC2616 will cause this error message, such as a web server response which includes a Content-Length header indicating a smaller value than the length of the data in the response. Another common cause of this error message is an extra HTTP 100 Continue message, which may be included in a POST response by Microsoft Internet Information Services (IIS) version 6.0.

     Have modifications been made to the underlying load.ashx code?  I’m finding the most recent builds are returning invalid HTTP headers on the response, which is causing our load balancer to discard and fail the resource requests.

     Can you outline what changes that have been made to writing out load.ashx?  I need to provide specific details to my technical team to discuss the implications so we can come up with the best fix to the problem in my live production system.

     
    We are  day 3 since the reporting and discovery of this problem, and I still have not heard back from you regarding this matter.

     Your response would greatly be appreciated.

  •  01-10-2012, 2:15 AM 72581 in reply to 72561

    Re: URGENT: LOAD.ASHX CAUSES MAJOR ISSUES WITH LOAD BALANCER

    Hi,
     
    Yes, the code have something wrong for load balancing.
     
    Please add this to web.config to fix it as a temp solution:
     
    <appSettings>
        <add key="CuteEditorIgnore304" value="True" />
    </appSettings>
     
    (The version we updated it 3 dyas ago)
     
    Regards, Terry
     
  •  01-10-2012, 8:52 AM 72590 in reply to 72581

    Re: URGENT: LOAD.ASHX CAUSES MAJOR ISSUES WITH LOAD BALANCER

    Thanks for getting back to me with a response so quickly. 
     
    It's great you released a version 3 days ago, and waited till now to tell me a temporary fix was available. Even better is the CuteEditorIgnore304 web.config setting - I never would have been able to figure that out last Friday after downloading the update and installing it without this message.
     
    Can you please explain - what is the problem, what is the temporary fix, and what does it do for me, and how can I be assured that pushing this fix out will not cause more problems? 
     
    I would like to review the temporary fix to load.ashx before I push it out to my production systems.  We have used cutesoft editor for  a long time and I'm here to help, so can I review the source code changes you have implemented specific to load.ashx? 
     
    You have my email address from the original support email when my system was down, and which I sent on Thursday 5-Jan-2012 (Today is 10-Jan-2012).  Please send code snippets there. 
     
  •  01-11-2012, 7:24 AM 72625 in reply to 72590

    Re: URGENT: LOAD.ASHX CAUSES MAJOR ISSUES WITH LOAD BALANCER

    I am still awaiting a response in this matter.
  •  01-11-2012, 7:58 AM 72627 in reply to 72590

    Re: URGENT: LOAD.ASHX CAUSES MAJOR ISSUES WITH LOAD BALANCER

    Hi,
     
    The load.ashx will check the request headers
     
    If the header 'if-modified-since' is found , the load.ashx will return http status 304
     
    And that not works for some cases.
     
    The CuteEditorIgnore304 setting just disable to check the header 'if-modified-since'
     
    So load.ashx will not return the 304 , and also will not cause that error again.
     
    Regards,
    Terry
  •  01-11-2012, 8:26 AM 72628 in reply to 72627

    Re: URGENT: LOAD.ASHX CAUSES MAJOR ISSUES WITH LOAD BALANCER

    I would like to review the temporary fix to load.ashx before I push it out to my production systems.  We have used cutesoft editor for  a long time and I'm here to help, so can I review the source code changes you have implemented specific to load.ashx? 
     
    You have my email address from the original support email when my system was down, and which I sent on Thursday 5-Jan-2012 (Today is 11-Jan-2012).  Please send code snippets there. 
  •  01-11-2012, 9:26 AM 72631 in reply to 72627

    Re: URGENT: LOAD.ASHX CAUSES MAJOR ISSUES WITH LOAD BALANCER

    From the  RFC2616 - Where exactly are you out of compliance?  What exactly is the cause of the bug?
    10.3.5 304 Not Modified
       If the client has performed a conditional GET request and access is
       allowed, but the document has not been modified, the server SHOULD
       respond with this status code. The 304 response MUST NOT contain a
       message-body, and thus is always terminated by the first empty line
       after the header fields.
     
       The response MUST include the following header fields:
     
          - Date, unless its omission is required by section 14.18.1

     

       If a clockless origin server obeys these rules, and proxies and

       clients add their own Date to any response received without one (as

       already specified by [RFC 2068], section 14.19), caches will operate

       correctly.

     

          - ETag and/or Content-Location, if the header would have been sent

            in a 200 response to the same request

     

          - Expires, Cache-Control, and/or Vary, if the field-value might

            differ from that sent in any previous response for the same

            variant

     

       If the conditional GET used a strong cache validator (see section

       13.3.3), the response SHOULD NOT include other entity-headers.

       Otherwise (i.e., the conditional GET used a weak validator), the

       response MUST NOT include other entity-headers; this prevents

       inconsistencies between cached entity-bodies and updated headers.

     

       If a 304 response indicates an entity not currently cached, then the

       cache MUST disregard the response and repeat the request without the

       conditional.

     

       If a cache uses a received 304 response to update a cache entry, the

       cache MUST update the entry to reflect any new field values given in

       the response.

     
     
     
    Which cases will the 304 not return?  All of them? Or just some of them?  Exactly what?
     
    Was this the only change?
     
    Cuteeditor was working with my F5 load balancer  with the CuteEditor 6.6 Build 2011-05-19.  When was this change introduced?
     
     
  •  01-12-2012, 7:16 AM 72647 in reply to 72631

    Re: URGENT: LOAD.ASHX CAUSES MAJOR ISSUES WITH LOAD BALANCER

    I am still awaiting a response in this matter.  THIS IS IMPORTANT.
  •  01-13-2012, 10:26 AM 72682 in reply to 72627

    Re: URGENT: LOAD.ASHX CAUSES MAJOR ISSUES WITH LOAD BALANCER

    I am still awaiting a response in this matter.  THIS IS IMPORTANT.
  •  01-19-2012, 7:59 AM 72746 in reply to 72627

    Re: URGENT: LOAD.ASHX CAUSES MAJOR ISSUES WITH LOAD BALANCER

    I am still awaiting a response in this matter.  THIS IS IMPORTANT.
     
    I find it incredible that the cutesoft policy of customer support is to ignore the customer until they go away or stop complaining.
  •  01-19-2012, 7:10 PM 72751 in reply to 72746

    Re: URGENT: LOAD.ASHX CAUSES MAJOR ISSUES WITH LOAD BALANCER

    HI,
     
    I am very sorry that these days I didn't back and check this post .
     
    Here is the previous logic :
     
    if( header contains IF-MODIFIED-SINCE )
    {
         Send304NotModified();
         Response.End();
         return;
    }
    ContinueToSendFileData();
     
     
    and here is the curent logic :
     
    if( header contains IF-MODIFIED-SINCE )
    {
        if( app-settings CuteEditorIgnore304 != "True" )
        {
             Send304NotModified();
             Response.End();
             return;
        }
    }
    ContinueToSendFileData();
     
     
    --
    I think the Send304NotModified() have bug that it didn't send enough response headers as you said .
     
    But as you can use CuteEditorIgnore304 to skip that bug code , So you can get avoid that bug .

    These days we are busy on the CuteEditor7 development . So we haven't scheduled to fix it yet.
     
    If you still want the server send 304 header , please let's know , we will try to fix it .
     
    Regards,
    Terry
     
     
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