Netty VS Aeron

Code of netty is here and using following library

We use Netty (https://netty.io/) as the source of the MQTT communication, and we build the MQTT features the MQTT broker should support ourselves on top of that.

In this space, we also have the somewhat related term blocking. Java's NIO library is one well-known non-blocking tool used for managing multiple tasks on a single Java thread. When listening to sockets, most of the time a thread is just blocked, doing nothing until it receives some data. So, it's efficient to use a single thread for monitoring many sockets, to increase the likelihood of the thread having some actual work to do. The Selector API does this but is notoriously challenging to program well. Instead, developers use frameworks like Netty which abstract some of NIO's complexity and layer on some best practices.

DirectByteBuffer exhibits an intriguing behavior: it deallocates its backing memory during the finalization process, which occurs after garbage collection (GC) cycles. This poses an issue if your system is conservative with on-heap allocations, leading to infrequent GC cycles. In such cases, there could be a significant delay between the time the memory becomes unreferenced and when it is actually deallocated. This behavior could, in some respects, mimic a memory leak.

This is why some libraries hacks into DirectByteBuffer to deallocate memory explicitly, bypassing the finalizer altogether. For instance, the Netty library has implemented such a workaround, see Netty as an [example](https://github.com/netty/netty/blob/795db4a866401aa172757b95...).

Apologies replying to myself, but Netty, which underpins many of the popular Java backend frameworks, see backward compatibility as more important than supporting green threads.

https://github.com/netty/netty/issues/12816

It'll be interesting to see who (if anyone) picks up Netty's mantle in the Project Loom world.

Looks fairly recent so I'm glad I had a pre oct22 build https://github.com/netty/netty/issues/12737

This is better? https://github.com/netty/netty/blob/4.1/pom.xml

Given the fact that Lettuce is built with Netty, we also immediately noticed quite an impact on the initialization time (cold start) of our lambda function. Netty is really fast while executing, but takes a bit of time to initialize. The new Lambda Snapstart functionality might help with that.

Semi-related is the Aeron project: https://github.com/real-logic/aeron

- ez itt most egy izgalmasabb product (trading/matching engine, low latency code, aeron alapokon)

Look into Aeron for examples of high performance UDP message sending. We use it for high performance audio messaging, and I previously used it in high frequency trading https://github.com/real-logic/aeron. It is written in Java/C, but the general concepts of back pressure and reliable delivery over UDP are well documented.

They mention their training offer on the Aeron GitHub page here: https://github.com/real-logic/aeron

Yup the Disruptor paper actually shocked the industry a bit, b/c it was so out of place. BTW, Martin Thompson went on improving the Disruptor, and the result is the Aeron Protocol: https://github.com/real-logic/aeron

I was about to suggest Chronicle, but it looks like they have gone closed-source. The older version is still interesting to look through though. Aeron / Disruptor / SBE are good projects for inspiration as well.

We are using this Java Aeron (https://github.com/real-logic/aeron) to build our production distributed messaging cluster. As a Rust lover, Is there any similar lib or framework in our ecosystem to test benchmark with it?

Java: In the past years C++ in finance has been rapidly supplanted by Java thanks to breakthrough technologies in the past decade like LMAX Disruptor, Chronicle Queue, Azul JVM, and Aeron (not the ergonomic chair, but this one, the transport protocol that breaks kafka performance records out of the park - not really a full kafka replacement, as Kafka enforces subscriber GD and aeron is more of an OSI layer 4 better than TCP; google "Best-effort delivery vs reliable delivery"). There's plenty more but thanks to these technologies, they allowed a Java based stack to perform the latency and throughput requirements needed for high frequency trading/HFT. From top trading firms like Two Sigma to the New York Stock Exchange, they're in Java. For banks, large modern western banks worth their salt and have modernized their systems are dominated by Java, especially thanks to Azul. To list a few banks, ING, Wells Fargo, Credit Suisse, and Barclays are all in Azul. Even at work Java still dominates.