"Type 'Newtonsoft.Json.Linq.JToken' is a recursive collection data contract" While Adding Service Reference in VS2012

Trying to add a service reference in Visual Studio 2012 to Bing Maps SOAP service I got the following error message:

Cannot import wsdl:portType
Detail: An exception was thrown while running a WSDL import extension: System.ServiceModel.Description.DataContractSerializerMessageContractImporter
Error: Type 'Newtonsoft.Json.Linq.JToken' is a recursive collection data contract
...

Following Getting “Recursive collection data contract” when referencing a WCF service with a slightly complex method and Visual Studio 2012 Error Reference.svcmap throwing Error I've had to change the "reuse types in referenced assemblies" from "all" to everything except Newtonsoft.JSON and RestSharp.

Might not be something to write home about, but I'm sure I'll forget where it is was in a year or so.

PS. This seems to be VS2012 only issue, VS2010 worked just fine.

Tech-Ed Eilat 2010

So happy to be presenting at Tech-Ed Eilat 2010.
See you all at the Herods Hotel, Tue 30/11 at 11:15 where we would share our lessons from the field on enterprise web content management with SharePoint 2010.

You can read more about our session at the realcommerce web site.

IIS JNLP 404 Problem

If your IIS 6 returns a 404 Not Found when you request a Java Web Start jnlp file, then you probably need to add the jnlp mime-type to the IIS configuration.

IIS Settings -> Right click the machine -> mime-types -> new Extension: .jnlp MIME Type: application/x-java-jnlp-file

How to do rewrites in an IIS ISAPI

Note to self: If ever you need to do a rewrite in an IIS ISAPI Filter you just need to re-set the pHeaderInfo's url header. Something like this:

 
pHeaderInfo->GetHeader(pCtxt->m_pFC,
              "url",strUrl.GetBuffer(dwUrlSize+1),&dwUrlSize);
strUrl.ReleaseBuffer(); 
strNewUrl = GET_REWRITE_FOR_URL(strUrl); 
if ( strNewUrl.IsEmpty() == FALSE ) {  
    pHeaderInfo->SetHeader(pCtxt->m_pFC, 
              "url", (LPTSTR)(LPCTSTR)strNewUrl);  
} 
return SF_STATUS_REQ_NEXT_NOTIFICATION; 

This is working in IIS4 and above.

Note that if you really need a good re-write/redirect filter for IIS you should look at IIRF ,but since it's not working for IIS4 i had to do this manually

Bing, Google, Nutch and Canonical URLs

Google announced a few months back that they started supporting canonical urls. This is a great feature that we already adopted in a couple of sites (mostly to keep tracking codes from messing with our search engine results.

Unfortunelty, altough Microsoft announced they will support this feature in Live, this was not yet implemented in Bing as of now (Jun 2009).

Nutch, on the other hand, had this on thier TODO list for 1.1.

Also, Google Search Appliance (GSA), is currently assumed by all to not support this (although nobody really knows if it does).

More about canonical URLs:
http://googlewebmastercentral.blogspot.com/2009/02/specify-your-canonical.html
http://searchengineland.com/canonical-tag-16537
http://janeandrobot.com/library/url-referrer-tracking

many group by strategies to select single rows per group

Xaprb gives a good explanation for selecting a single row from a group: How to select the first/least/max row per group in SQL at Xaprb.

apc futex_wait lockdown make your apache freeze over

We had the typical LAMP setup going on, with Drupal as the base CMS and APC for bytecode cache. We needed a good caching engine so I figured why not use APC's user cache. Well, we tried the APC Cache Drupal Module which, with minor fixes proved to work very nicely. That is, until we actually put this all thing on production.

The first thing we had was having our apache hang and not respond to any user requests. We susspected network issues, especially since netstat -na showed that all the apache processes were hanging on SYN_WAIT. However, since apache restart solved the issue i started to suspect this was something else.

To make a long (very long) story short, I got strace on our prod machines to find out that apache was either hanging on futex_lock(....FUTEXT_WAIT...) or doing infinte loops on the same functions.

To make even a longer story short, I got gdb installed on those machines and the backtrace clearly indicated that the locks were from APC user-cache calls.

We decided to abandon APC user-cache and switch to memcached which proved faster and had less lockdowns.

The funny thing is that when we talked about this over dinner the same evening a developer from another team just pointed me to this article by one of the APC leaders: (or something) How to Dismantle an APC Bomb which has been around for over a year. I am supprised and shocked that such a information is hidded so well and not mentioned anywere in the docs. Moreover, I went through the APC code again after reading this post (I went through it once when i started analysing the problem) and it seems that this is not even close to being resolved. there are no patches and no TODOs and nothing of the sort. From reading the code the entire user-cache needs a major re-write. What gives?

(this is a post i wrote a couple of months ago, never had time to finish it. Unfortunately this is still not fixed afaik)
EDIT (07/2009): http://pecl.php.net/bugs/bug.php?id=15179 reports this to be fixed. If anyone can confirm this please send me a note so that I could update this post