Thursday, November 13, 2008

Steps For Data Replication

Steps to Data Replication

We must take care of the following thing before starting data replication

1. The amount of data you need to be copied


The amount of data that need to be copied will determine the bandwidth of the network required to move that amount of data. This is also the part that people don't really think about until they find out how much bandwidth they really need.

2. Available network bandwidth
If you only have a dial-up connection between sites, you may as well back up the Chevy truck and start loading tapes to be shipped to your disaster site. As a good rule of thumb, you will need about 10M bit of bandwidth for each M byte of data you need to copy per second. As an example, a T3 link can handle almost 5M bytes of data per second.
3. Distance between locations
The distance will determine what kind of remote copy solution you can use, synchronous or asynchronous. Under sync replication an I/O is not complete until it is written to both sides. This is a good thing because your transactions stay consistent. Every write written to the primary side is written "in-order" to the remote side before the application sees an "I/O complete" message.
The problem here is that Fibre Channel protocol requires four round trips to complete every I/O under sync replication. Even using dark Fibre cables between sites, the speed of light becomes your limiting factor because of the four round trips -- you lose about a millisecond for every 25 miles. Sync is limited in distance to about 100 kilometers. After that, application performance goes in the toilet. Async can go around the planet. So the farther you go, the more you need async remote copy.
4. Type of operating systems and how many servers involved
Software-based replication products work great. The problem arises when you have hundreds of servers to copy data from. Buying a software license for 200 servers at the primary location and another 200 licenses for the servers that need to be at the remote site can get very expensive. Also, I don't know of a software package yet that can be used with every operating system. If you have AIX, Solaris, Netware, NT, Windows 2000 and VMS, you may need a several separate software solutions. For a homogenous NT or Unix environment though, software works great and can save you money.
5. Whether or not clustering is being used
Most cluster solutions require real-time connectivity for heartbeat and locking for quorum resources. If you use clustering software like MSCS and want to stretch the cluster between locations so that all your applications transparently fail over, you will need to be within sync replication distances.
6. Availability of storage, servers and floor space at the remote site
If you have your own data center for your remote site, you're fine. If you need to lease space from a provider, you want to make sure your solution is as compact as possible. Server and storage consolidation must be considered prior to introducing hosted disaster recovery solutions. Hey, when you're paying by the foot you want to have very small feet!
7. and last but not least, your available budget
This is a no-brainer. Many companies, when faced with the real-world costs of disaster recovery, tend to get shell-shocked. Consider the costs:
• Floor space
• Servers for the recovery site
• Staff for the recovery site
• Storage hardware and licenses
• Software licenses
• Services to implement the solution
• Services to determine what needs to be copied, and why
• Network links (this is usually the most expensive part)
• Network-based SAN extension gear
The costs can add up quick. This sometimes makes the CTAM method look like a wonderful idea. (CTAM = Chevy Truck Access Method or, dump your backup tapes in the back of a truck and drive your data to the remote site).

Data Replication

What is data Replication

Here I am going say a brief about data replication and data transformation which will helpful for your enterprise server and desktop needs. Today as you know most organizations depend on data from multiple databases. And data replication is a set of techniques for copying and distributing data and database objects from one database to another and then synchronizing between databases to maintain consistency. Using replication we can distribute data over local and wide are networks, dial-up connections, Internet etc.

We can use transactional replication server to server which require high throughput, including improving scalability and availability for example data warehousing and reporting, and may need to integrate data from multiple sites,

Steps to be followed in data replication

Monday, April 28, 2008

ASPNETDB Problem: Unable To Connect To Sql Server Database

Sometimes trying to implement security in website using website administration tool this error may occurred by saying “Unable to connect to sql server database”. Before going to see the problem we need to discuss about how to create administrative user.

To create an administrative user


Run the web site once before proceeding. This ensures the initialization of the Membership and Roles databases.

In the Website menu, click ASP.NET Configuration.

Click the Security tab.


When first time showing this error I created ASPNETDB database in sql server database using regsql utility in windows\Microsoft.net\Framework\v2.0\50727 and now can see the ASPNETDB database in sql server. But now also I can see the same error as “Unable to connect to Sql server database”.

Then I tried to connect the app.net application with the server. Now no problem in connecting to sql server database also. From the study to solve this error I realized some causes to occur this error.

Possible causes of this error are not giving role manager enabled correctly

In the web.config we need to put enable rolemanager enabled as true. For your reference I am giving my working web.config as giving in the

"





"


After giving the in the web.config if shows that error you may not give the connection correctly

To correct this Choose Data Store" button and go to “Provider” tab and click on to single provider. In the next page only one option remaining "AspNetSqlProvider". Select this
And click “Test” link.

Hope it will work fine. If any any “SQLExpress database file auto-creation error:” occurs Pls check that you have installed SQLEXPRESS database and
Its service is running correctly.

Wednesday, April 23, 2008

How to Create Aspnetdb, Asp.net membership provider database using aspnet_regsql command - asp.net membership provider,role provider,profile provider

ASP.NET Membership

ASP.NET membership is a built in way to validate and store user credentials.And Asp.Net membership helps in user authentication in websites. We can implememt membershipprovider by Asp.net Forms authentication and Login control.

Purppose Of Membeship provider

1. Create new user with username and password.

2. Storing membership information in Sql Server,Active directory etc.

3.Authentication of users. By using ASP.NET login control,ASp.NET usercreation wizard etc implement complete authentication system.

4.Fascilitate role management etc

The database used to access membership database is normaly created with name ASPNETDB.MDF. Here is how to install ASPNETDB database


Creating ASPNETDB DATABASE in your SQLEXPRESS
ASPNETDB.MDF is membership provider database and is used for storing and retrieving
membership data from database and here we are going to see how to create membership provider database . The command used to create Aspnetdb.mdf is ASPNET_RegSQL.EXE


1.Start->Programs->Microsoft visual studio 2005->visual studio tools->Visual Studio 2005 command prompt. Type ASPNET_RegSQL.EXE in the visual Studio 2005 command prompt

2. A wizard with the heading " Welcome To The Asp.Net Sql Server Wizard " will be displayed. Here need to click Next

3. Next a wizard with " Select Setup Option " will displayed. Now we need to select setup option “Configure sql server for application purpose is default”. Select which one you wants and next.

4. A window with " Select Sql Server Database " Will be shown Now we need to select our sql server database. Here needs to set server, authentication type and database.
If select the default name"aspnetDb.mdf" will be selected. If you wants to modify existing database select that database.

5.Now A confirm will be displayed with heading "Confirm your Settings". Now check servername and database name and click next.

6. A window with " The database Has Been Created Or Modified " Will displayed. Now click Finish


These all are how to create an asp.net membership database on sql Server 2005 database


GOD BLESS YOU
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