java-socket-test

A simple Java socket client to test TCP connections to a server.

Background

When developing a notification pushing server for Android OS, a widely used method is to keep a TCP connection between server and android client. However, there are limits in Linux for how many files a process could open, so we have to optimize system configuration to improve the limits, say using "ulimit -n" to improve hard limits and soft limits. After optimizing, we need a client to test how many TCP connections a server could support, this is why this project is created.

Setting up project

This project uses Intellij IDEA as IDE and gradle as build script, to set it up, you could:

• Fork code in github or clone the repository to your local disk;
• Open IDEA and use "Import Project..."; Or you could run "gradle cleanIdea idea"(which maybe not work sometimes)

Usage

• You could adjust host、port and connection limit in Main class and run main method directly;
• Or you could run "gradle clean jar", and run "java -jar build/libs/java-socket-test.jar "

You'd better to know

• This project will reconnect for up to 11 times if failed to connect to a server, and it will sleep for 24 hours to keep all TCP connections alive;
• For a client, it will try to connect to server continuously without sleeping, so that you could easily get a huge number of connections quickly;
• For a client, there might be a OS level limit for TCP connections, so if it failed, it might be a client problem instead of a server problem;
• You'd better install this tool on different machines, say 10 PCs, so that you could get 10(clients) * 10000(connections/client)=100,000 connections.