The importance of profiling your application

It is well known that the ORM can help a lot in software development. In fact, they solve many problems that as developers we had in the past, specially talking about Opening and Closing Connections.
But as ORM frameworks are a powerful tool,they can also make a mess if they are not used in the proper way. Let me give you an example.
In the project I'm current working on, some users started experiencing some slowness when trying to load a page. I was assigned to investigate what was happening and propose a solution. I started by doing some profiling in the web application using Glimpse, adding some Trace messages to determine where was the problem and I noticed that the it was in a WCF service call that was taking 20 seconds to retrieve a single record with a lot of columns (because of all the needed joins).
This was by far unacceptable, so I started to doing further profiling on the Entity Framework using Entity Framework Profiler, and discovered that the slow service data was being fulfilled by a 4,000 lines query!.
I clearly understand that EF made a lot of extra and maybe unnecessary joins in order to automate the data exctraction, but, 4000 lines?! Really?!
After inspecting the long long query that EF Profiler showed me, I started noticing some duplicated SELECT statements. Then I went back to the service call and noticed that the code was something like this:

...
AsQueryable()
.Include("Account")
.Include("Account.Client")
.Include("Account.Client.Organization")
...

This seemed to be good on the first look, since we wanted to get the Account, the Client of that Account, and the Organization. But what EF is understanding is that we want to get the Account, and then AGAIN the Account and the Client, and then AGAIN the Account, AGAIN the Client and the Organization. This then was causing that duplicated SELECT statements I was talking before. So to fix the problem I deleted the extra lines and the code ended up like this

...
AsQueryable()
.Include("Account.Client.Organization")
...

and then by that, I reduced the lines of the resulting query, removed all the duplicated SELECT and reduced the execution time to 2 seconds!
So, as you can see, two extra lines can screw all the work you're doing. So be careful of preventing this and do profile your applications before they go live. CodeProject

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Creating CodeCollaborator reviews using command line

Some months ago, I started using CodeCollaborator to create code reviews and ensure our developments have the desired quality.

We are at the end of our development sprint, so I tried to create some code reviews using the CodeCollaborator GUI with no success. Aparently, one of the latest Java VM updates "broke" my client; actually because we are using an old version of CodeCollaborator client (v 4) which cannot work under the latest versions of Java.

So if you run into the same problem, or just want to create your reviews using the command line follow the next steps described below. (Disclaimer: this was only tested on Windows and using SVN as source control, since that's our current development environment),

1. Open the command line prompt
2. Go to your working copy folder, some thing like this
   cd "C:\Folder\Folder\MyProjectWorkingCopyRoot"
3. Login into your CodeCollaboration Server
   

   ccolab login  [ServerUrl] [UserName] [Password]
   

   You will get something like this

   Connecting to Code Collaborator Server https://[your.server.url]/
   Connected as: [Your name and username]
   
   New configuration worked - saving configuration settings
   Configuration key 'url' saved.
   Configuration key 'user' saved.
   Configuration key 'password' saved.
   Configuration key 'server-proxy-host' cleared.
   Configuration key 'server-proxy-port' cleared.
   

4. You can upload specific files, changelists, etc. In my case I needed upload all the changes made on an specific revision, so I needed to pass a SVN diff as a parameter
   

   ccollab addsvndiffs new -r 27183:27190

   If you look I added the parameter "new" wich means I'm creating a new review (and will be named "Untitled Review"); you can also pass the review-id if you want to add files to an existing review.

With this, you can easily add files when creating or updating any CodeCollaborator review. For more information go to the CodeCollaboration command line reference 

CodeProject

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Overcome to Windows Azure free trial cancellation by adding a new plan

I decided to try Windows Azure more than 3 months ago, most likely because of it's free 90-day offer. I can tell that I'm amazed on all the posibilies you have for free (Websites, Virtual machines, Mobile Services, etc.).

So then, I decided I wanted to continue with the service after my trial period ended by "acquiring" a Pay-As-You-Go plan (that as the name says, you pay only what you use only if you use it, so at the time of my purchase my total was $0.00).

Since I was swamped with many things at job, I didn't payed much attention on the warning e-mails saying that my account was about to expire. As it might be expected, my account was cancelled 2 weeks ago. Last week I was trying to upgrade my account, so I signed up on the Pay-As-You-Go plan but after several tries and wating days, I still wasn't able to use it to create new websites with it.

So this is the process that you need to follow in order to be able to use your new plan in your account:

1. Acquire a new plan (Pay-As-You-Go, 6 or 12 month, etc.)
2. Go to Preview Features page and select the feature that you want to enable for your new plan, in my case I wanted to be able to create websites again
3. Click on "Try it now"
4. Select the plan you want to associate (your new plan). In this case I'm showing an example with Media Services because I already joined to the Websites preview

After completing this, you will see a label on the screen saying that the feature is active

and you will be able to create websites (or any of the preview features that you selected) under your new plan

Sadly, my previous websites remain cancelled and it doesn't seem to be possible to associate them with my new plan, or at least I couldn't find a way to edit them on the manage portal.

So, if possible try to avoid your account cancellation, but if that already happened, this post might help you if your plan is not shown on some items on your account.

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Solution to: "The operation failed: The relationship could not be changed because one or more of the foreign-key properties is non-nullable"

The operation failed: The relationship could not be changed because one or more of the foreign-key properties is non-nullable. When a change is made to a relationship, the related foreign-key property is set to a null value. If the foreign-key does not support null values, a new relationship must be defined, the foreign-key property must be assigned another non-null value, or the unrelated object must be deleted.

Problem description

The error quoted above happened to me after I started using AutoMapper on my WCF service for updating my entities. Previously, I had a "manual map" to assing the properties that I received on my data contract to the entity that I got on my context and update it. When we decided to implement AutoMapper on our project, my mapping code started like this:

Mapper.CreateMap<MyDataContract, MyEntity>.IgnoreAllNonExisting();

Since all my properties were named the same on both classes, everything seemed to be easy peasy.

But sadly, I started gotting the error message

The operation failed: The relationship could not be changed because one or more of the foreign-key properties is non-nullable. When a change is made to a relationship, the related foreign-key property is set to a null value. If the foreign-key does not support null values, a new relationship must be defined, the foreign-key property must be assigned another non-null value, or the unrelated object must be deleted.

This message was driving me crazy, because of the text I was thinking that I was making something wrong with the FK relationships on the Database, or in someway the field was being passed null without being null on the contract, or somebody changed the table in someway (yeah sure, blame others :-P). After some deep look on the code (including debugging line by line all the updating process) I found the error.

Since I'm copying the modified values (from DataContract to Entity) when mapping, I'm passing all the values from one instance to the other. This sounds OK, right? I mean, I want all my changes to be persisted on the database.

Well, is not that easy. Since my contract comes from a web application, when saving there I don't have all the navigation properties. When this is the case and I just map all, I'm also mapping and overwriting the values of this navigation properties, that in this case are null on my DataContract. This makes the Entity to update the ForeignKey Columns that belong to that navigation property to be null too. That is why the error says that you're sending null values, because actually you are.

Solution

Since the problem is that we're mapping null navigation properties, and we actually don't need them to be updated on the Entity since they didn't changed on the Contract, we need to ignore them on the mapping definition:

ForMember(dest => dest.RefundType, opt => opt.Ignore())

So my code ended up like this

Mapper.CreateMap<MyDataContract, MyEntity>
ForMember(dest => dest.NavigationProperty1, opt => opt.Ignore())
ForMember(dest => dest.NavigationProperty2, opt => opt.Ignore())
.IgnoreAllNonExisting();

And voilà! the problem is solved. CodeProject

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There's no reason to be scared, anybody can code now. So just do it!!

I was thinking over this days on how the development tools have evolved. I think that anybody can just start doing code now, with only some little training or just following some of the courses that exist over the Internet. I've been working on software for several years, and as I can tell that I hadn't a really hard time as the first Assembly or C coders did, things weren't as easy as they are now.

Obviously, this doesn't mean that anybody can be a Programmer, even less a Software Engineer. For getting into that, I think, there are more topics that need to be covered beyond how to code or use an IDE. Concepts of data structures, memory management, networking and OS internals are really important to do the things correctly, not just doing them.

But for that, there's a lot of info too. Even more, there are some schools or private institutions that offer "converting" your non-software degree onto something pretty similar to a Bachelor on Computer Sciences.

Thanks to the new Visual Studio 2012, Nuget, Entity Framework, MVC3/4, WebApi, etc. starting on the .net world is much more easier than it was 6 years ago. Frameworks like jQuery and YUI are helping people to get into the Javascript world with much less difficulty, and the same has happened with Cake for PHP and Spring/SpringRoo on Java.

So there is no reason to be scared, anybody can code now. So if you have an idea, or you've wondered if can do coding as a hobby, just do it! Maybe you have a million-dollar idea ;)

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Tic-Tac-R source code

After some tweaks, I'm releasing the source code of the Tic-Tac-R game. As you may find on the previous post, this game is an experiment on how to make a simple Tic-Tac-Toe game in a real-time web application using SignalR and host it on a cloud environment using Windows Azure.

I hope you find it useful for learning just as I did

Download the source code on Github

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Updates to Tic-Tac-R. Now it works on Windows Azure =)

This is an update of my previous post

Update: Post with the source code of the game

After spending a lot of time testing and searching on the web, I wasn't able to get the Tic-Tac-R game on my Windows Azure website. I tried a lot of things and can shameless say that I was totally lost, since my application was working fine on a shared hosting environment (GoDaddy) but not on my Windows Azure.

Thanks to an anonymous user that replied my question on StackOverflow I was able to know that this is a weird issue only happening there with some sort of caching by Windows Azure (neither really a bug on my app nor SignalR). The suggestion was changing enforce the transport to be Long Polling and with that the app started to work no the cloud. It is kinda little slow though, and I feel that some times the call that I make from the browser is lost, but is's maybe just my imagination... Time and more testing will give us the answer... In the meanwhile, you play the game can be part of the beta testers of this simple game... It's free!! =P

By the way, I updated SignalR to the just released 0.5.3 version and everything seems to keep working fine..

I hope you can share your opinion regarding Tic-Tac-R. It will be really appreciated it =)

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