withClientName internal implementation changes from 5.x to 6.x

[Akaame]

We have upgraded a dependency that itself depended on lettuce-core so an upgrade from 5.1.6 to 6.1.1 versions has taken place.

We are creating the Redis URI to the "managed GCP Redis" as follows:

private RedisClient redisClient() {
  return RedisClient.create(RedisURI.builder()
    .withClientName(properties.getRedis().getClientName())
    .withHost(properties.getRedis().getHost())
    .withPort(properties.getRedis().getPort())
    .build());
}

Earlier the withClientName option was working as expected. And with the new version it issues a CLIENT SETNAME foo command which is prohibited by GCP's Redis. Therefore, Redis connection setup fails.

Questions:

1. How was this working earlier?

Some hints I have found the understand this change in behavior.

/**
* @param clientName
* @deprecated since 6.0, use {@link RedisAsyncCommands#clientSetname(Object)}.
*/
@Deprecated
public void setClientName(String clientName) {
  CommandArgs<String, String> args = new CommandArgs<>(StringCodec.UTF8).add(CommandKeyword.SETNAME).addValue(clientName);
  AsyncCommand<String, String, String> async = new AsyncCommand<>(
          new Command<>(CommandType.CLIENT, new StatusOutput<>(StringCodec.UTF8), args));
  state.setClientName(clientName);

  dispatch((RedisCommand) async);
}

And this PR:
abbfdf6

My understanding:
Earlier this was being passed along during connection setup. And now the connection is set up and necessary CLIENT subcommands are issued to further customize it. Can someone from the contributors/maintainers verify this?

2. How do we get around this given the limitation from GCP Redis

Naive way would be prefixing every key with foo: as I think CLIENT SETNAME does exactly that anyway.

Thanks in advance and cheers.

[mp911de]

It looks as if your Redis server rejects the CLIENT SETNAME command. If you're using Redis 6, then you could enable RESP3 as RESP3 uses the HELLO command to initialize the connection and that takes the client name as well.

[Akaame]

Hallo and thanks for the quick answer. If I connect to a Redis 6.x instance with RESP3 enabled, will the client automatically prefer the new protocol or is there a toggle on the client side?

[mp911de]

By default, it will try to use RESP3 and fall back to RESP2 if the server doesn't support it. You can force a protocol version through ClientOptions and set it via RedisClient.setOptions(…)