persistence.md

Work with Persistence

Introduction

This lab will walk you through using Persistence with Coherence.

Coherence persistence is a set of tools and technologies that manage the persistence and recovery of Coherence distributed caches. Cached data is persisted so that it can be quickly recovered after a catastrophic failure or after a cluster restart due to planned maintenance. Persistence and federated caching can be used together as required.

Estimated time: 10 minutes

Objectives

In this lab, you will:

• Create a snapshot of the cache data
• Clear the cache data
• Recover the snapshot
• Replicate data to the secondary cluster

Prerequisites

• You should have completed the previous labs.

Task 1: Create a Snapshot

1. Switch to the primary cluster dashboard and use Persistence -> Create Snapshot to create a snapshot of the current cache data. Wait for confirmation that the snapshot has been created before continuing. Note the count of the Positions.

   

   Note: Coherence will ensure that the data in the snapshot is consistent.

Task 2: Clear the primary data

1. Use Tools -> Clear Cache to remove the cache data from the primary cluster. As we have federation configured, this will be replicated to the secondary cluster.

   

   Note: Confirm that the data has also been removed from the secondary cluster.

Task 3: Recover the Snapshot

1. Switch to the primary cluster dashboard and use Persistence -> Recover Snapshot to recover the snapshot data.

   Once the data has been recovered, you will see the updated data in the dashboard.

2. To ensure that the secondary cluster is updated after recovering a snapshot, you need to re-enable federation by selecting Federation -> 'Replicate All`.

   Confirm that the secondary cluster data has also been updated.

Acknowledgements

• Author - Tim Middleton
• Contributors - Ankit Pandey, Sid Joshi
• Last Updated By/Date - Ankit Pandey, November 2024