1. Whats Remoting?

A: In one line – Interprocess communication in distributed computing.

2. How far distributed?

A: Across the world over internet.

3. Unterstanding remoting from a simple use case?

A: There are 3 parts to the simple use case for remoting:

          a. Remotable object. (Data which travels on the channel)
          b. Host application domain to listen for requests for that object. (Server)
          c. Client application domain that makes requests for that object. (Client)

Lets start with a simple application in Visual Studio…the project will demonstrate a Patient service and remotable Patient objects.

There will be 4 projects

1. Remoting.ClientAccess (Just the interface which the client needs to access the objects on the server)
2. Remoting.ServerObject (Implementation of the interfaces from point 1)
3. RemotingServer (The console application running as server to listen to requests)
4. RemotingTest (The client console application which will make RPCs using the interfaces in point 1)

Project 1 //Remoting.ClientAccess //build it into a library

namespace Remoting.ClientAccess
{
    public interface IPatient
    {
        int PatientCode { get; set; }
        string FirstName { get; set; }
        string LastName { get; set; }
        int HospitalCode { get; set; }       
    }
}

namespace Remoting.ClientAccess
{
    public interface IPatientService
    {
        void SavePatient(IPatient patient);
    }
}

Project 2 //Remoting.ServerObject // build as a library //reference to project 1

namespace Remoting.ServerObjects
{
    [Serializable]
    public class Patient : System.MarshalByRefObject ,IPatient
    {
        private int ptCode;
        private string fName;
        private string lName;
        private int hospCode;
        #region IPatient Members

        public int PatientCode
        {
            get
            {
                return ptCode;
            }
            set
            {
                ptCode = value;
            }
        }

        public string FirstName
        {
            get
            {
                return fName;
            }
            set
            {
                fName = value;
            }
        }

        public string LastName
        {
            get
            {
                return lName;
            }
            set
            {
                lName = value;
            }
        }

        public int HospitalCode
        {
            get
            {
                return hospCode;
            }
            set
            {
                hospCode = value;
            }
        }
       
        #endregion
    }
}

[Serializable]
    public class PatientService : System.MarshalByRefObject, IPatientService
    {

        #region IPatientService Members

        public void SavePatient(IPatient patient)
        {
            Console.WriteLine(“First name : ” + patient.FirstName);
            Console.WriteLine(“Last name : ” + patient.LastName);
            Console.WriteLine(“Code : ” + patient.PatientCode);
            Console.WriteLine(“Hosp code : ” + patient.HospitalCode);
        }      

        #endregion
    }

Project 3 //RemotingServer // build as a console application //reference to project 1,2

namespace RemotingServer
{
    class Program
    {       
        static void Main(string[] args)
        {
            RemotingConfiguration.Configure(“RemotingServer.exe.config”);
          
            Console.WriteLine(“Press return to exit”);
            Console.ReadLine();
        }
    }
}

Here is the config file which is used in above code:

<?xml version=”1.0″ encoding=”utf-8″ ?>
<configuration>
  <system.runtime.remoting>
    <application>
      <service>
        <wellknown mode=”Singleton” type=”Remoting.ServerObjects.Patient, Remoting.ServerObjects” objectUri=”Patient.rem” />
        <wellknown mode=”Singleton” type=”Remoting.ServerObjects.PatientService, Remoting.ServerObjects” objectUri=”PatientService.rem” />
      </service>
      <channels>
        <channel ref=”tcp” port=”8000″>
          <serverProviders>
            <!–provider ref=”wsdl” / –>
            <!–formatter ref=”soap” typeFilterLevel=”Full” /–>
            <formatter ref=”binary” typeFilterLevel=”Full” />
          </serverProviders>
          <!–clientProviders>
            <formatter ref=”binary” />
          </clientProviders–>
        </channel>
      </channels>
    </application>
  </system.runtime.remoting>
</configuration>

Project 4 //RemotingTest // build as a console application //reference to project 1

namespace RemotingTest
{
    class Program
    {
        static void Main(string[] args)
        {
           
            IPatientService ptSvc = (IPatientService)Activator.GetObject(typeof(IPatientService), “tcp://172.16.11.22:8000/PatientService.rem”);
            IPatient pt = (IPatient)Activator.GetObject(typeof(IPatient), “tcp://172.16.11.22:8000/Patient.rem”);
            pt.FirstName = “Vaibhav”;
            pt.LastName = “Gaikwad”;
            pt.PatientCode = 23423 ;
            pt.HospitalCode = 234 ;
            ptSvc.SavePatient(pt);
        }
    }
}

Execute the server application and then execute the client application

http://mhada.maharashtra.gov.in/?q=lottery3863

The above link will display a table which all the schemes and categories, which can lead you to the respective PDF files which contains the results. So how to directly access the results, here is how it goes…

General link discovery:

http://www.graphitech.in/mhada/win/207SCWIN.pdf means scheme=207, category=SC, WIN stands for winner and is common for all the links.

So if you want to see results for scheme 227 with category SG then try access file 227SGWIN.pdf on the same base url, this is true for all the schemes and categories.

Categories:

For scheme code check you application forms

Best of luck

I had some requirement which includes all of the above topics. So after completing my test code I thought of publishing it here for educational purposes.

check it out if you need to do something similar or if you are stuck with some intermediate part:

http://vaibhavgaikwad.wordpress.com/web-services-with-reflection-in-net/

-Bugs!

http://vaibhavgaikwad.wordpress.com/reflection-with-interfaces-with-c/

-Bugs!

vaibhav@vaibhav-laptop:~/web_dev/asp.net$ sudo apt-get install subversion
Password:
Reading package lists… Error!
E: Dynamic MMap ran out of room
E: Error occurred while processing trn4 (NewVersion1)
E: Problem with MergeList /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_dapper_multiverse_binary-i386_Packages
E: The package lists or status file could not be parsed or opened.
vaibhav@vaibhav-laptop:

Did some internet search on it but was helpless. Then finally one article stated that it might be a cache size issue for apt-get, and the resolution was to add the below line in /etc/apt/apt.conf, but that file was missing.

“APT::Cache-Limit “8388608″;

So here is how you can resolve the issue without the apt.conf file.

sudo apt-get update -o APT::Cache-Limit=8388608

-Bugs! 

I tried the same trick within a test application which has “shiporder.xml” and “shiporder.xsd”, these files were taken from w3c
http://www.w3schools.com/schema/schema_example.asp

I created the class using xsd.exe from VS.NET tools, which created “shiporder.cs” for me:
cmd>> xsd shiporder.xsd /c

Then I build a simple and sweet standalone application to test it.
//code c#
using System.IO;
using System.Xml.Serialization;
namespace XSDTest
{
class Program
{
static void Main(string[] args)
{

// shiporder.cs
XmlSerializer serial = new XmlSerializer(typeof(shiporder));
TextReader reader = new StreamReader(“shiporder.xml”);

// this is how you directly get the data back.
shiporder so = (shiporder) serial.Deserialize(reader);

}
}
}
//end code
 

I hope I will be able to resolve the reference schemas in the HL7 xsds, and then build the classes out of it in near future, till then try out other possible methods -Bugs

-Bugs!

If you are playing with XML using .NET libraries, then you might be familiar with below mentioned exception:
System.Xml.XPath.XPathException: ‘objOfXmlDocument[@attribute={value containing single-quote}]‘ has an invalid token.
If you are looking for a patch for the above mentioned problem, then you are at the right place.
Sample xml text: //test.xml
<?xml version=”1.0″ encoding=”utf-8″ ?>
<root>
<emp fname=”Vaibhav” lname=”Gaikwad” />
<emp fname=”Lavina” lname=”D’cunha” />
</root>
//code to access the test.xml
class Program
{
static void Main(string[] args) {
XmlDocument doc = new XmlDocument();
doc.Load(“test.xml”);
string ln = “D’cunha”;
// This fails (  resulting in XPath exception.
XmlNode n = doc.SelectSingleNode(“/root/emp[@lname=' "+ ln +" ']“);
}
}  
So, the issue is due the single-quote inside the XPath expression.
We try to resolve it using the “concat” function of XSL, and this is the helper function:
public static string GetXPathString(string input) {
string[] fragments = input.Split(new char[] { ‘\” });
string result = “”;
result += “concat(””;
for (int i = 0; i < fragments.Length; i++)
{
result += “, ‘” + fragments[i] + “‘”;
if (i < fragments.Length – 1)
{
result += “, \”‘\”";
}
}
result += “)”;
return result;
}
And here is how you modify the above code so as to use our new function:
// remember to remove the single-quotes after = and ]

 -Bugs!

// CLSID_CorRuntimeHost from MSCOREE.DLL

[ Guid("CB2F6723-AB3A-11D2-9C40-00C04FA30A3E"), ComImport]
class CorRuntimeHost {}

// IID_IcorThreadPool  

[ Guid("84680D3A-B2C1-46e8-ACC2-DBC0A359159A"),InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface ICorThreadpool {
// Note that IUnknown Interface members are NOT listed here:
void RegisterWaitForSingleObject();
void UnregisterWait(); 
void QueueUserWorkItem();
void CreateTimer(); 
void ChangeTimer(); 
void DeleteTimer(); 
void BindIoCompletionCallback(); 
void CallOrQueueUserWorkItem();
void SetMaxThreads(uint MaxWorkerThreads, uint MaxIOCompletionThreads);
void GetMaxThreads(out uint MaxWorkerThreads, out uint MaxIOCompletionThreads);
void GetAvailableThreads(out uint AvailableWorkerThreads, out uint AvailableIOCompletionThreads);}

//Here is the sample code for the consumption of these types. CorRuntimeHost runtimeMgr = new CorRuntimeHost();
// QueryInterface for the ICorThreadPool interface
ICorThreadpool coreThreadPool = (ICorThreadpool)runtimeMgr;
uint maxWorkerThreads;
uint maxIOThreads;
coreThreadPool.GetMaxThreads(out maxWorkerThreads, out maxIOThreads); // this returned me 50, 1000
coreThreadPool.SetMaxThreads(25,1000); //setting max of 25 threads

//end code

This code is tested on .NET 2.0, and if you face any issues for 1.0 or 1.1 please let me know.-Bugs!

Here’s what you can do:

The Mscoree.h has the definitions for MAX limit of thread pool, and there are APIs for getting/setting it.

What is Mscoree.dll?
Mscoree.dll is the .NET Runtime Execution Engine.

So how can you change the default size of ThreadPool?
Using the definitions in Mscoree.h we can define a COM interop dll, as mentioned below
using System;
using System.Runtime.InteropServices;
[Guid("CB2F6723-AB3A-11D2-9C40-00C04FA30A3E"), ComImport]
class CorRuntimeHost {}

[Guid("84680D3A-B2C1-46e8-ACC2-DBC0A359159A"),InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
interface ICorThreadPool
{
void slot0(); // max threadpool settings
void slot1();
void slot2();
void slot3();
void slot4();
void slot5();
void slot6();
void CorSetMaxThreads( uint MaxWorkerThreads, uint MaxIOCompletionThreads );
void CorGetMaxThreads( out uint MaxWorkerThreads, out uint MaxIOCompletionThreads );
void CorGetAvailableThreads( out uint AvailableWorkerThreads, out uint AvailableIOCompletionThreads );
}
// Ok you are done with the COM interop, now build this into a class library (e.g. ThreadPool.dll )

Then you must consume the dll into you application, and using the APIs of this managed dll you can now change the default ThreadPool size. Here how you go about doing it.

uint maxWorkerThreads;
uint availWorkerThreads;
uint maxIOThreads;
uint availIOThreads;

ICorThreadPool iThreadPool ;
iThreadPool = (ICorThreadPool)new CorRuntimeHost();
iThreadPool.CorGetMaxThreads(out maxWorkerThreads, out maxIOThreads);
iThreadPool.CorGetAvailableThreads(out availWorkerThreads, out availIOThreads);
System.Console.Writeline(“Available worker threads : ” + availWorkerThreads);
System.Console.Writeline(“Available IO threads : ” + availIOThreads);
iThreadPool.CorSetMaxThreads(30,availIOThreads); // changing worker threadpool size from 25 to 30

Hmm! so we are done

-Bugs!