Maximum concurrent Socket IO connections

Question

This question has been asked previously but not recently and not with a clear answer   Using Socket io  is there a maximum number of concurrent connections that one can maintain before you need to add another server    Does anyone know of any active production environments that are using websockets  particularly socket io  on a massive scale  I d really like to know what sort of setup is best for maximum connections   Because Websockets are built on top of TCP  my understanding is that unless ports are shared between connections you are going to be bound by the 64K port limit  But I ve also seen reports of 512K connections using Gretty  So I don t know

User · Answer

After making configurations  you can check by writing this command on terminal sysctl -a   grep file

User · Answer

For  300k concurrent connection  Set these variables in  etc sysctl conf  fs file-max   10000000  fs nr open   10000000  Also  change these variables in  etc security limits conf    soft nofile 10000000   hard nofile 10000000 root soft nofile 10000000 root hard nofile 10000000  And finally  increase TCP buffers in  etc sysctl conf  too  net ipv4 tcp mem   786432 1697152 1945728 net ipv4 tcp rmem   4096 4096 16777216 net ipv4 tcp wmem   4096 4096 16777216  for more information please refer to this

User · Answer

This guy appears to have succeeded in having over 1 million concurrent connections on a single Node js server   http   blog caustik com 2012 08 19 node-js-w1m-concurrent-connections   It s not clear to me exactly how many ports he was using though

User · Answer

I tried to use socket io on AWS  I can at most keep around 600 connections stable   And I found out it is because socket io used long polling first and upgraded to websocket later   after I set the config to use websocket only  I can keep around 9000 connections    Set this config at client side   const socket   require  socket io-client   const conn   socket host    upgrade  false  transports    websocket

User · Answer

This article may help you along the way  http   drewww github io socket io-benchmarking    I wondered the same question  so I ended up writing a small test  using XHR-polling  to see when the connections started to fail  or fall behind   I found  in my case  that the sockets started acting up at around 1400-1800 concurrent connections   This is a short gist I made  similar to the test I used  https   gist github com jmyrland 5535279

[websocket] Maximum concurrent Socket.IO connections

Examples related to websocket

Examples related to socket.io