# Upgrading a Reverse Proxy from Netty 3 to 4

DevFeed: [Upgrading a Reverse Proxy from Netty 3 to 4](<https://devfeed.tech/articles/upgrading-a-reverse-proxy-from-netty-3-to-4-15936.md>)

Original publisher: [Read original article](<https://developer.squareup.com/blog/upgrading-a-reverse-proxy-from-netty-3-to-4>)

Author: Square Engineering

Published: 2016-08-09T16:12:00Z

Content type: article

Language: en

Sources: [Square Corner Blog RSS Feed](<https://devfeed.tech/sources/square-corner-blog-rss-feed.md>)

Topics: [Netty](<https://devfeed.tech/topics/netty.md>), [HTTP](<https://devfeed.tech/topics/http.md>), [Microservice](<https://devfeed.tech/topics/microservice.md>), [Java](<https://devfeed.tech/topics/java.md>), [Remote Procedure Call (RPC)](<https://devfeed.tech/topics/rpc.md>), [gRPC](<https://devfeed.tech/topics/grpc.md>), [Mobile](<https://devfeed.tech/topics/mobile.md>)

Tags: [engineering](<https://devfeed.tech/tags/engineering.md>), [http](<https://devfeed.tech/tags/http.md>), [infrastructure](<https://devfeed.tech/tags/infrastructure.md>), [java](<https://devfeed.tech/tags/java.md>), [memory](<https://devfeed.tech/tags/memory.md>), [microservice-architecture](<https://devfeed.tech/tags/microservice-architecture.md>), [migration](<https://devfeed.tech/tags/migration.md>), [performance](<https://devfeed.tech/tags/performance.md>), [proxy](<https://devfeed.tech/tags/proxy.md>), [rpc](<https://devfeed.tech/tags/rpc.md>), [threading](<https://devfeed.tech/tags/threading.md>), [upgrade](<https://devfeed.tech/tags/upgrade.md>)

## AI overview

Square describes upgrading Tracon, its reverse HTTP proxy powered by Netty, from Netty 3 to Netty 4. The article explains the motivation for the migration, including Netty 3 reaching end of life and the need to proxy HTTP/2 for mobile clients and gRPC infrastructure, and discusses issues encountered during the completed upgrade.

## Source excerpt

Tracon is our reverse HTTP proxy powered by Netty. We recently completed an upgrade to Netty 4 and wanted to share our experience.