Change tcp_nodelay config to be true

[milindl]

Currently, we use Nagle's algorithm, which doesn't make much sense as we're already implementing batching behaviour with linger.ms. In cases the user wants to optimize the latency and sets linger.ms = 0, it will still be delayed, which is undesirable/buggy behaviour.

[confluent-cla-assistant]

🎉 All Contributor License Agreements have been signed. Ready to merge.
_{Please push an empty commit if you would like to re-run the checks to verify CLA status for all contributors.}

[Copilot]

PR Overview

This PR updates the default configuration for the TCP_NODELAY setting to improve latency when batching with linger.ms. The changes include:

• Updated the changelog to indicate that the Nagle algorithm is disabled (TCP_NODELAY enabled) by default.
• Modified the configuration documentation to change the default value of socket.nagle.disable from false to true.

Reviewed Changes

File	Description
CHANGELOG.md	Updated changelog entries to reflect the new default setting for TCP_NODELAY.
CONFIGURATION.md	Changed the default value for socket.nagle.disable from false to true.

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

[marcin-krystianc]

I fully support this change. I was surprised to discover that the current default setting utilizes Nagle's algorithm. I only became aware of this while investigating some unexpected latency spikes in our benchmarks, which were resolved upon disabling Nagle's algorithm (socket.nagle.disable=true).

[emasab]

Thanks @milindl ! We decided to ship it as a patch and not in a major release because it's only giving improvements if QUICKACK isn't enabled on the other side, and this last one is a flag that needs to be reapplied after every read to the socket. Even if any broker implementation was setting QUICKACK after every read and this change was causing increased acks, a small increase in network traffic would be better that an increase in latency (and it would be already be happening with a Java client).