Stateless Component

 

I have moved my blog to http://www.janakiramm.net. My RSS feed is located at http://www.janakiramm.net/blog/SyndicationService.asmx/GetRss

I have been a BizTalk developer sometime back. I used it for one of the large B2B pilots that we did couple of years back. Obviously, I was curious to learn about WWF and figure out when and where to use it.

Yesterday I presented a quick intro on WWF at MUGH User Group Meet here at Hyderabad.

I want to explain this technology the way I understand it. I hope this helps some of you who are confused even after reading some intro articles on MSDN.

Many of us write enterprise applications that has complex business logic. This business logic will obviously have a decent chunk of code that contains some conditional branching.

Think of a scenario where an employee places an internal order for a new notebook computer. The system has to check if the employee is a full time employee before it sends a notification to the manager for his approval.

After the approval process completes, it then goes onto checking the internal inventory for that specific product.If the internal stock is empty, the system goes about generating a PO and calls a Web Service to place an order with the vendor. Then it waits till the Web Service sends an acknowledgment with the order confirmation number and a tentative date of shipping. The process is completed by sending a mail to the employee with the acknowledgment details.

 

Let’s translate the above scenario into a pseudo code.

 

public void PlaceOrder(Employee e, Product p)

{

   if(e.FTE)

   {

       if (GetManagerApproval(e,p))

       {

           Inventory i=InventoryServiceProxy.GetInventory(P.ProductID);

    

          if(!i.InStock)

           {

              PurchaseOrder PO=new PurchaseOrder(p,1);

              OrderAck Ack=OrderServiceProxy.SendPO(PO);

              SendMail(“Placed New Order”,”Order #” + Ack.OrderNo +” Expected on ” + ACK.ShipDate, e.EmailID);

           }

        }      

     }

     // Rest of the code goes here

}

 

While the above scenario looks very normal and the code looks very familiar, think of some of the possible issues that may crop up over a period of time.

 

• The company wants to allow even interns to place a new order.
• The approval process now involves a procurement manager’s approval even before the employee’s manager approves it.
• With the vendor providing local ware houses at each city, the company wants to do away with local inventory maintenance and wants to directly check with the vendor’s nearest warehouse.
• For some strange reasons, the acknowledgement also needs to be sent as a SMS or IM alert to the employee.

 

Unfortunately, our code has no capability to adapt to these requirements and align itself with the changing business requirements. Ideally we should isolate this kind of branching from core business logic.

We should let an analyst or a business manager define and re-define this kind of branching. Actually this perfectly qualifies to be a Workflow. The business logic should have ‘hooks’ to these workflows that run outside of the context of the core business logic. Whenever the workflow needs to be executed, the biz logic should invoke the current workflow definition either synchronously or asynchronously based on the scenario.

WWF efficiently lets a developer convert the decision branching part of the code into an independent and insulated workflow entity from the core business logic.

Using the intuitive designer, any business decision maker can alter the workflow and persist it back into the system. The cool thing about WWF is that the workflow designer can be shipped with your app that runs independent of Visual Studio.  

As I first mentioned in post, this is my initial understanding of WWF. If you feel I am inaccurate in conveying some of the points, drop a comment and I will be glad to go back to do my homework J

The following WWF model depicts the logic that we discussed above.

So, Here is my Step-By-Step guide to configuring a Wi-Fi network with BSNL DataOne. Though many wireless routers claim that it is a no-brainer setup to configure the wireless network, I found it to be not as easy as it looks to be. For example, NetGear comes with a wizard that never works with BSNL broadband connected via HUAWEI SmartAX 880. For those of you desperate to take your BSNL DataOne broadband wireless, follow these steps. It took me more than 2 days to figure and come out with these configuration details.

 

Before I start, let me share what I have:

 

1)     BSNL DataOne 256Kbps connection.

2)     HUAWEI SmartAX MT880 (The modem supplied by BSNL).

3)     NetGear WGR614v5

 

There are 2 steps to configuring your wireless network. First, you have to change the default settings of the SmartAX MT880 modem and configure it to enable PPPoE (PPP over Ethernet). Second, you have to configure the NetGear Router to talk to the modem.

 

Keep your modem, wireless router and your username and password from BSNL handy before you proceed to the next step.

 

If you want to change your existing configuration, take a backup of your configuration. This guide is to build your network from the ground-up.

 

1)     Configuring and testing your Broadband connection

·         Setup the modem as per the instructions mentioned in the manual. Ensure that the RJ11 (thin) cable from the splitter is connected to the ADSL port and the RJ45 cable connects your machine to the Ethernet port of the modem.

 

·         Change the IP properties of your Ethernet card to the following:

192.168.1.2

255.255.255.0

192.168.1.1

 

·         Open the browser and type http://192.168.1.1 to go to the HUAWEI configuration tool.

 

·         Enter ‘admin’ as username and ‘admin’ as password

 

·         Expand the Home node and select the WAN Setting

 

·         Under this web page, configure the following:

PVC Number – PVC 0

Wan Type – PPP

Connection Type – PPPoE

VPI/VCI – 0 / 35

Default Route - Enabled

User Name – <Your ISP UserName>

Password – <Your ISP Password>

Use DNS – Enabled

Max Idle Time – Always On

 

·         Click on Apply and allow the modem to restart.

 

·         Close the browser window

 

·         Open the browser and type http://192.168.1.1

 

·         Enter ‘admin’ as username and ‘admin’ as password

 

·         You should see the Summary page. The Status is normally Red indicating that the connection is not ON.

 

·         Click on the Plug icon in the Note column to connect.

 

·         After the Connecting message, you should see the summary page again with the Status turning Green. Notice the IP Address and the Gateway Address.

 

·         Expand Tools node and click on Misc.

 

·         Type  www.msn.com and click on Ping

 

·         You should see Ping Result: Successful

 

·         Click on the Lan Settings link under the Advanced node.

 

·         Configure the following:

IP Address – 192.168.1.90

Subnet Mask – 255.255.255.0(/24)

Local Domain Name – Blank

 

·         Click on Apply and allow the modem to restart

 

·         Open the Network properties of your Ethernet card and change the IP properties to the following

 

 

IP Address – 192.168.1.2

Subnet Mask – 255.255.255.0

Default Gateway – 192.168.1.90

Preferred DNS server – 61.1.96.69 (BSNL DNS Server IP)

Alternate DNS server – 61.1.96.71 (BSNL DNS Server IP)

 

·         Open your browser and type your favorite URL. You should be online by this time!

 

 

2)     Configuring the Wireless Router and enabling the WPA security

·         Connect the network cable from the NetGear wireless router to the machine.

 

·         Open the IP Properties of your Network card and Enable DHCP. Select the following on the IP properites dialog.

Obtain IP Address Automatically

Obtain DNS Server Address Automatically

 

·         Open the browser and type http://192.168.1.1/basicsetting.htm

 

·         Enter ‘admin’ as username and ‘password’ as the password

 

·         Click on Wireless Settings link on the navigation pane and configure with the following values

 

Wireless Network

Name (SSID) - <YourSSID>

Region – Asia

Channel – 11

Mode – g and b

Security Options

WEP (Wired Equivalent Privacy)

Security Encryption (WEP)

Authentication Type – Automatic

Encryption Strength – 64bit

Security Encryption (WEP) Key

Passphrase - <YourPassphrase>

·         Click on Generate

 

·         Record the value of Key1 – This is required when you log on to your Wi-Fi network the first time.

 

·         Click on Apply and wait till the router reboots

     (Wireless will not be enabled till you complete the next step)

 

·         Click on the Basic Settings link on the left side navigation pane and configure the following

 

Does your Internet connection require a login? – No

Account Name – blank

Domain Name – blank

Internet IP Address

Use Static IP Address

IP Address – 192.168.1.91

IP Subnet Mask – 255.255.255.0

Gateway IP Address – 192.168.1.90

Domain Name Server (DNS) Address

Use These DNS Servers

Primary DNS – 61.1.96.69

Secondary DNS – 61.1.96.71

Router MAC Address

Use Default Address

·         Click on Apply and wait till the router restarts

 

·         Connect the Network Cable coming from the ADSL Modem to the Wireless Router

 

  

Few things to remember –

·         Don’t connect the ADSL Lan Cable to the Internet Uplink port of the Wireless Router. It never worked for me. Always connect it to one of the 4 ports excluding the designated Internet port.

 

·         IP Addresses can be anything of your choice. But it is a good idea to follow the 192.168.x.x convention

 

·         If you get lost any time, feel free to reset the configuration by poking a pin into the reset slot on the modem and the router.

 

·         Don’t compromise on the security. Always enable WPA and save your key. Don’t let your friendly neighbors ride on your network!

 

Have a happy Wi-Fi surfing and drop a comment in case you want more inputs.