Near Cache Data Not Getting Deleted Despite All Storage Enabled Nodes Go Down (Doc ID 1063840.1)

Last updated on NOVEMBER 29, 2023

Applies to:

Goal

This document explains how the near caches can preserve data on clients despite all cache servers may have been shut down. This is the data from orphaned partitions.

Following the steps below this behavior can be oberved:

1. Start a storage enabled node
2. Start a cache client (let's call it "client 1")
3. Do a put on the NearCache
4. Do a get of the recently put entry key --> it is returned OK
5. Shutdown the storage enabled node (if you try to do a put after the storage enabled node shutdown, then you will get a "storage is not configured" error)
6. Do a get of the recently put entry key --> it is returned OK again (despite there are no storage enabled nodes running on the cluster)
7. Startup a storage enabled node again
8. Do a get of the recently put entry key --> it is returned OK again

• If you had another client node (let's call it "client 2") before shutting down the storage enabled node, it will keep the entry put on step 3.
• If you add a new client (let's call it "client 3") to the cluster after step 7 and try to do the get of the key put on step 3, then you will get a null value, which is not the same value contained by clients 1 and 2, which means that it's an incoherent (inconsistent) near cache.

Solution

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