Reading an item from a JPA backed remote cache returns null

[wolframite]

I'm using 9.0.0 Final embedded client/server talking to each other via Hot Rod.

Keys set by the client can be read back, but keys which are still in the database are not transferred over.

I wrote a test client to demonstrate the behaviour:

Configuration config = new ConfigurationBuilder().addServer().host("localhost").port(11222).build();
RemoteCacheManager remoteCacheManager = new RemoteCacheManager(config);
RemoteCache<String, Object> remoteCache = remoteCacheManager.getCache("main");

log.info("Size: {}", remoteCache.size());
for (String key : remoteCache.keySet()) {
   log.info("Key: {}", key);
   log.info("Kontainski: {}", remoteCache.containsKey(key));
   log.info("Value: {}", remoteCache.get(key));
}

That's the result:

Size: 3

Key: hallo
Contains Key: true
Value: test

Key: hallo3
Contains Key: true
Value: 12.5

Key: hallo5
Contains Key: false
Value: null

The key hallo5 is in the database and I can retrieve it when I'm on the server like this:

embeddedCacheManager.getCache("main").get("hallo5");

Here's my persistence configuation on the server:

primaryCacheConfigurationBuilder.persistence()
    .passivation(false)
    .addStore(JpaStoreConfigurationBuilder.class)
        .shared(true)
        .preload(false)
        .persistenceUnitName(readthroughPersistenceUnitName)
        .storeMetadata(false)
        .entityClass(entityClass)
        .ignoreModifications(true);

Any hints are welcome :-)

[wolframite]

I just tried the same with a JdbcStringBasedStore, which works fine. The problem is that I want to write the store data from another non-Java application and have it read from the server, which is impossible due to the serialization in the database. I will check the source code to see if it's a bug or a "feature"...

It looks like this is not a new issue:

How to load cache from an existing table for a remote server with HotRod client?

[wolframite]

When everything's local, the key object coming in to JpaStore.load(Object key) is a String, when the request is made via Hot Rod client, the key is a WrappedByteObject and the wrapped key contains a 3-byte prefix. What is the best way to convert that WrappedByteArray to the original String? Changing it via an interceptor somehow seems a bit unclean. Any ideas how this can be solved properly?

[ryanemerson]

I might have misunderstood your requirements, but I believe Compatibility mode is what you require.

[wolframite]

Damn, I'm such an idiot, I know the setting, but I didn't connect the dots. Works like a charm now, thank you so much for saving me tons of time!