Hazelcast IMDG

WAN Replication

Feature of IMDG Enterprise HD, and Enterprise

Replicate the State of your Clusters over Wide Area Network (WAN) through Hazelcast® WAN Replication

WAN Architecture Diagram

Imagine you have different data centers in New York, London and Tokyo each running an independent Hazelcast cluster. Every cluster would be operating at native speed in their own LAN (Local Area Network), but you also want some or all record sets in these clusters to be replicated to each other: updates in the Tokyo cluster should also replicate to London and New York and updates in the New York cluster are to be synchronized to the Tokyo and London clusters.

Hazelcast WAN Replication allows you to keep multiple Hazelcast clusters in sync by replicating their state over WAN environments such as the Internet. Hazelcast supports two different operation modes of WAN Replication:

  • Active-Passive: This mode is mostly used for failover scenarios where you want to replicate an active cluster to one or more passive clusters, for the purpose of maintaining a backup.
  • Active-Active: Every cluster is equal, each cluster replicates to all other clusters. This is normally used to connect different clients to different clusters for the sake of the shortest path between client and server.

Main Features of Hazelcast WAN Replication

  • You can configure the WAN replication for Hazelcast Map (IMap) and Hazelcast JCache (ICache) data structures.
  • Generic WAN Replication Endpoints: Hazelcast Enterprise users can create their own WAN replication publishers and/or consumers and use them seamlessly instead of out of the box WAN replication implementations that come with Hazelcast Enterprise:
    1. WanBatchReplication sends replication events to the target cluster after either a pre-defined number of replication events are generated or a pre-defined amount of time is passed.
    2. SolaceWanPublisher allows WAN Replication users to use Solace, a high performance enterprise grade messaging solution, rather than direct cluster socket connections. The user could then make use of Solaces guarantees for message delivery and also their monitoring tools.
  • Besides the basic configurations, Hazelcast WAN Replication has several advanced configuration options and capabilities to meet your enterprise requirements:
    • Response timeout.
    • Replication queue capacity.
    • The behavior when the replication queue becomes full
    • Interception of WAN replication events before they are placed to WAN event replication queues by providing a filtering API.
    • Two acknowledgment (ACK) type depending on your consistency requirements.
      • ACK_ON_RECEIPT: Events that are received by target cluster that are considered as successful.
      • ACK_ON_OPERATION_COMPLETE: This option guarantees that the event is received by the target cluster and it is processed.
    • Initiation of a synchronization operation on an Hazelcast Map (IMap) for a specific target cluster.