Your application may be deployed to multiple data centers either for disaster recovery or for geographical load balancing of traffic. And, if your application is high traffic, it must use an in-memory data grid. In these situations, you need to ensure that your in-memory data grid can do WAN replication.
TayzGrid provides Bridge Topology to handle WAN replication of in-memory data grid. Bridge Topology does asynchronous replication of data so there is no performance degradation of both caches and also your application.
Bridge Topology deals with two different in-memory data grid clusters in each location. Bridge Topology forms a Bridge in-between both data grid clusters and this Bridge is itself a cluster of two servers for high availability purposes.
When an operation is performed on one data grid cluster (source data grid), it is asynchronously handed over to the Bridge. Bridge then adds this operation to its operations queue. Bridge then goes through each operation in the queue and performs it on the target data grid cluster so it is synchronized with the source data grid and the WAN Replication is done. The Bridge ensures that:
You may have one active and one passive datacenter primarily for disaster recovery purposes. In this case, you have the following in-memory data grids:
The data grid could be using any data grid topologies that TayzGrid supports and active and passive data grids do not need to have the same data grid topology although they’re usually the same topology.
If the active site goes down, you would typically route all the traffic to your application deployed on the passive disaster recovery site. This passive site application then starts using the in-memory data grid seamlessly because this data grid is already synchronized with all the updates in the previously active site.
Later, when your originally active site comes back up, you can go through a few simple steps and reconfigure your Bridge to its original active-passive configuration without stopping either the data grid or your application. And, these steps also ensure that the temporarily active data grid’s data is now moved to the originally active data grid.
You may have two active datacenters for a combination of regional load balancing and an implied disaster recovery purposes. In this case, you have the following data grids:
The data grid could be any topologies that TayzGrid supports and both active data grids do not need to have the same data grid topology although they’re usually the same topology.
If the one of the active sites goes down, you would typically route all the traffic to your application running in the other active site. This traffic is handled seamlessly by this other active site because the in-memory data grid is already replicated through the WAN by the Bridge.
Later, when your downed active site comes back up, you can go through a few simple steps and add it back to the Bridge. When this happens, this newly added active data grid receives all the data from to other active data grid through the Bridge so both data grids are synchronized. And, all of this happens automatically and without stopping your data grid or your application.
If you have an active-passive Bridge configuration, you can easily switch it to active-active or reverse active-passive order (meaning make active data grid passive and passive data grid active) all at runtime and without stopping any of the data grids or the Bridge.
This flexibility gives you the power to easily handle disaster recovery situations. For example, if your active data grid in an active-passive goes down, the passive data grid now becomes active. But, when the previously passive data grid is brought back up, you can now easily reconfigure it to become active and the currently active data grid to revert back to passive mode.
You can also choose to change an active-passive configuration to active-active without stopping the data grid or your application.