Offline Database Write Cache in C#

Question

I have a windows service that receives a large amount of data that needs to be transformed and persisted to a database. To ensure that we do not lose data, I want to create a "Write cache" for the data that will continue regardless if the database is online. Once the database becomes available again, I would want it to flush the content of the cache back into the database.

I've seen some articles indicating that I might be able to do this with NHibernate, but I haven't found it conclusively. What options exist for this, and is NHibernate the appropriate direction?

Answer 1

What if the write cache goes offline? Than you need another writecache to ensure the first writecache. This is a recursive pattern of creating (fake) availability. Use a cluster of multiple machines to make the chance of unavailability as small as possible. The availability of a sql database is probably higher than any other component in your system.

I don't handle these kind of exceptions in services, I just call the service again (indirect) with it's original input when it fails for downtime of any subsystem. The original input can be your "writecache".

Answer 2

Dear Todd

I am agreed with Paco but still there are some scenarios like if a database is being updated too frequently then you might need to implement as you are asking for.

This is called write-behind scenario

Look at the following article

http://wiki.tangosol.com/display/COH32UG/Read-Through,+Write-Through,+Refresh-Ahead+and+Write-Behind+Caching

If you think you really need it you can use NCache server http://www.alachisoft.com/ncache/

OR there are other applications available too to handle such situation and also you can write your own application or code to ensure this.

Regards Mubashar