A number of errors occurring in the java driver

[Lorak]

@Deus

When sending a request to the database, a list of WARNs (about 10 pieces) pops up and reports Advanced shard awareness: requested connection to shard 1, but connected to 0. Is there a NAT between client and server?, I tried for a long time, but it didn’t work I couldn’t solve this problem, I hope you can help me, the request is being executed, but seeing it constantly in the log is quite confusing

See my answer here: Questions about scylla java driver 4.x ShardAware feature and NAT issue - #2 by Lorak for a description of shard awareness and advanced shard awareness. Generally this error shouldn’t very be harmful. It affects only session creation, but after it is fully created (which may take a bit more time because of this problem) it will work exactly the same.
As to why it may occur - probably Docker on Windows uses some kind of NAT between Scylla and the driver. You may try to run the driver inside Docker too, but I can’t promise it will help. Maybe some Docker support channel would be a better fit for this question?

@Deus

Well, probably the strangest thing is request hashing, I hash the request so that the database is not loaded with prepared requests, but the error that the request needs to be hashed also appears, I have rewritten the code, maybe this is a problem on my part, please let me know Please

I’m not sure I get what you are aiming to do.
This code fragment:

.getCache()
.request(session.prepare(INSERT))

will always call session.prepare which will send a PREPARE request. Which is a bad idea because now you have 2 round trips for each statement you perform - first to prepare unnecessarily and then to execute.