Book Image

Getting Started with Hazelcast

By : Matthew Johns
Book Image

Getting Started with Hazelcast

By: Matthew Johns

Overview of this book

Table of Contents (18 chapters)
Getting Started with Hazelcast
About the Author
About the Reviewers

Backups everywhere and nowhere

As each node could disappear or be destroyed at any time without notice; in order to preserve the integrity of the overall persisted data, each partition is backed up on a number of other nodes and must be nodes other than the owner; an individual node can only hold each partition just once (either owning or backing up). Should a node die, the ownership of any partitions that were owned by the now defunct node will be migrated to one of the backups so that no apparent data loss is experienced. Additionally in the background, Hazelcast will start to replicate the migrated partitions over to another node to cater for the fact that there are now fewer backups available than was configured. This will restore resilience back to as it was configured. The number of backups that Hazelcast will create is configurable depending on your hardware's stability, appetite for risk, and available memory.

We can configure the number of backups to keep the method of creation;...