Why Use Replication?
Replication provides the capability to distribute changes from tables in one database to tables in another database. Target database tables receive a full initial copy of the source database tables and then the target database tables receive updates as data changes. Replication has several business applications:High Availability
Replication can be used to setup easy-to-use and low-risk high availability clusters. Replication-based clusters have several advantages over traditional backup methods:- Always have a running up-to-date server to handle planned or unplanned downtime
- Minimal impact on primary database
- No need for shared disks or other expensive hardware
- No need for lengthy failover and startup; your backup is already running
- No risk of backup not starting up; your backup is already running
For disaster recovery, replication has the following advantages:
- Have a running up-to-date backup in a remote site in case of primary site outages
- Only data changes are sent over the network, dramatically reducing network load and bandwidth requirements.
Performance
Databases performance is limited by CPU, RAM, and disk I/O. Adding servers is a fast and economical alternative to upgrading hardware that has minimal impact on the primary database. Replication can be used to offload read-only workloads to other hosts. For example, reporting applications can be offloaded from the primary database so that reporting queries have no impact on the primary database. Offloading can be done at the sime site or a different geographical location (such as the cloud), on the same or different networks with minimal load on the network.Controlled Deployment
Replication is an excellent choice for database and application migrations and upgrades. With replication, a new database or application can be deployed while the previous one is active. Once the new deployment is working, switch to the new deployment and reverse the replication direction. The old deployment is kept up-to-date in case there's a need to rollback, and is available for reports and read-only workloads that have not yet been upgraded.© ezReplicator, Inc. All Rights Reserved.