Skip to main content

Exchange Web Service - query problems

Exista mai multe versiuni de Exchange Server, majoritatea serverelor care exista la ora actuala sunt 2007 SP1 si 2010. Daca vrem sa scriem o aplicatie care acceseze direct contul de Exchange puteti sa folosim un client care consuma serviciile expuse de acest server precum EWS - Exchange Web Service. Aceasta este doar un assembly pe care trebuie sa il adaugam la proiect. Pregatesc in aceasta luna mai multe tutoriale despre EWS. In postul de azi vreau doar sa subliniez o problema pe care EWS o are. O sa vorbim mai in detaliu cu alta ocazie despre cum sa il folosim.
Exchange Server 2010 a adus cateva schimbari la nivelul entitatiilor care exista. De exemplu pe 2010 un contact poate sa aibe atasata o poza sau modul in care sunt grupate contactele difera fata de 2007. Din pacate EWS ne aduce datele in functie de versiune de Exchange pe care o accesam.
Un exemplu destul de bun, pentru a arata problema care o are EWS este cand vrem sa aducem lista de contactele a unui account. O sa ne trezim ca versiunea 2007 SP1 ne aduce obiecte de tip ExpandGroupResult, pe cand 2010 ne aduce obiecte de tip GroupMember.
Aceste probleme ma sperie, nu neaparat ca trebuie sa scriu un IF in plus, nu ar fi nici o problema, dar ce o sa ne facem cand apara urmatoarea versiunea de Exchange? Cand o sa dorim sa ne conectam la Exchange Server 20xx o sa ne trezim ca aplicatia crapa, deoarece rezultatele pe care il primim difera. Notiunea de backward compatible nu exista in acest caz si nici notiunea ca o metoda ar trebuii sa returneze un singur tip de data sau macar datele returnate sa aibe o interfata comuna, daca nu un base class.
Principala problema asa cum o vad eu vine de la libraria EWS. Chiar daca ea primeste de la server date de tipuri diferite, ar trebuii sa expuna consumatorului date de aceleasi tip.
Nu stiu ce schimbari o sa aduca urmatoarea versiune de Exchange, dar mentenanta pe aplicatiile care folosesc EWS nu o sa fie tocmai atat de placuta.

Comments

  1. Oare si ActiveSync are aceleasi probleme de backward compatibility?

    Am banuiala ca Exchange (ca si Lotus Domino), nu prea au fost gandite de la bun inceput sa fie folosite in mod curent de aplicatii externe third-party, ci mai degraba s-au focusat pe development-ul de aplicatii bazate pe clientii proprii, gen Outlook sau Lotus Notes.. (gen formuri cu VBScript respectiv LotusScript in spate..)

    ReplyDelete
  2. Cand faci public o librarie care este mapata peste propriile tale servicii, ma astept sa fie consistenta sau macar documentata.

    ReplyDelete
  3. Adevarat, asa ar trebui sa fie.. Din pacate, cu cat un API/web service e folosit de mai putine persoane, cu atat unii autori se simt mai putin motivati sa mentina backward/forward compatibility..

    ReplyDelete

Post a Comment

Popular posts from this blog

Windows Docker Containers can make WIN32 API calls, use COM and ASP.NET WebForms

After the last post , I received two interesting questions related to Docker and Windows. People were interested if we do Win32 API calls from a Docker container and if there is support for COM. WIN32 Support To test calls to WIN32 API, let’s try to populate SYSTEM_INFO class. [StructLayout(LayoutKind.Sequential)] public struct SYSTEM_INFO { public uint dwOemId; public uint dwPageSize; public uint lpMinimumApplicationAddress; public uint lpMaximumApplicationAddress; public uint dwActiveProcessorMask; public uint dwNumberOfProcessors; public uint dwProcessorType; public uint dwAllocationGranularity; public uint dwProcessorLevel; public uint dwProcessorRevision; } ... [DllImport("kernel32")] static extern void GetSystemInfo(ref SYSTEM_INFO pSI); ... SYSTEM_INFO pSI = new SYSTEM_INFO(

Azure AD and AWS Cognito side-by-side

In the last few weeks, I was involved in multiple opportunities on Microsoft Azure and Amazon, where we had to analyse AWS Cognito, Azure AD and other solutions that are available on the market. I decided to consolidate in one post all features and differences that I identified for both of them that we should need to take into account. Take into account that Azure AD is an identity and access management services well integrated with Microsoft stack. In comparison, AWS Cognito is just a user sign-up, sign-in and access control and nothing more. The focus is not on the main features, is more on small things that can make a difference when you want to decide where we want to store and manage our users.  This information might be useful in the future when we need to decide where we want to keep and manage our users.  Feature Azure AD (B2C, B2C) AWS Cognito Access token lifetime Default 1h – the value is configurable 1h – cannot be modified

What to do when you hit the throughput limits of Azure Storage (Blobs)

In this post we will talk about how we can detect when we hit a throughput limit of Azure Storage and what we can do in that moment. Context If we take a look on Scalability Targets of Azure Storage ( https://azure.microsoft.com/en-us/documentation/articles/storage-scalability-targets/ ) we will observe that the limits are prety high. But, based on our business logic we can end up at this limits. If you create a system that is hitted by a high number of device, you can hit easily the total number of requests rate that can be done on a Storage Account. This limits on Azure is 20.000 IOPS (entities or messages per second) where (and this is very important) the size of the request is 1KB. Normally, if you make a load tests where 20.000 clients will hit different blobs storages from the same Azure Storage Account, this limits can be reached. How we can detect this problem? From client, we can detect that this limits was reached based on the HTTP error code that is returned by HTTP