How "back-up configuration" work in Ignite cache?

Question

When an object is fetched from the persistence store by Ignite's cache using CacheStore, its backup copy is not created.

Can someone tell me how that back up works in Ignite for above scenario?

My Configuration:

Use cluster of two Ignite servers.
Cache properties.

cacheConfig.setWriteThrough(true);
cacheConfig.setReadThrough(true);
cacheConfig.setBackups(1);
cacheConfig.setWriteBehindEnabled(true);           
cacheConfig.setWriteSynchronizationMode(CacheWriteSynchronizationMode.FULL_ASYNC);
cacheConfig.setAtomicityMode(CacheAtomicityMode.TRANSACTIONAL);           
cacheConfig.setCacheStoreFactory(FactoryBuilder.factoryOf(ObjectLoader.class));

How do you check that backup is not created? Could you post a piece of code that you use to check it? Just in case, here is documentation on primary and backup cache nodes: apacheignite.readme.io/v2.1/docs/primary-and-backup-copies — Denis
To check backup and primary size use following code 1)cache.sizeLong(CachePeekMode.BACKUP) 2)cache.sizeLong(CachePeekMode.PRIMARY) — Rhishi

Denis Denis · Accepted Answer · 2017-08-23T08:34:34

When you create a cache with a configured cache store, data loading is performed by cache in a lazy manner. In your configuration you enabled read-through, so only that values that you actually read will be loaded from the cache store.

If you want to make sure that your cache has a backup copy, you have a few options:

Preload data (e.g. with help of loadCache or by reading some values from it) and then check cache size with BACKUP peek mode. It will show a number of keys stored on backup nodes.
Evaluate localPeek with BACKUP peek mode on a backup node. It will return a non-null value if the current node stores a backup copy of the cache.

How "back-up configuration" work in Ignite cache?

1 Answers