Replication in three tier architectures{4}


by David H
This article talks about the implement of unify all of transactions and reduplication in three tier architectures. The purpose of this is to provide data consistency and high availability for enterprise application. Many companies nowadays are using CORBA Object Transaction Services for the transaction which is to secure data that store in database and have backup recovery plan if it has problem in system. In addition, author mentions that using method of replication Fault Tolerant COBRA standard to protect the middle tier of servers. The goal of replicate middle tier because we want to secure application business logic processing. The way how it works is it replicates transaction coordinator which renders the two phase commit protocol non-blocking. This will prevent long service disruption of failure the coordinator. In order to perform of replicate middle tier server and database servers, the company need to reduplicate the gateway for restriction duplicate request that reaching database servers. Furthermore, the “client side fail over mechanism” will execute to produce outcome of client request.

This article relates to class because it demonstrates how three tier architectures affect significantly to application. In addition, we had discussed each of components of the tier which is client, application server, and database server. After reading this article, I have learned that how important to replicate the middle tier to prevent disruption issue in database server.

 

Reference

Zhao, W., Moser, L. E., & Melliar-Smith, P. (2005). Unification of transactions and replication in three-tier architectures based on CORBA. IEEE Transactions on Dependable and Secure Computing, 2(1), 20-33. doi:10.1109/TDSC.2005.14