Can't hold 100+ connections

[pvictorlv]

I've tested dotnetty in my server with 500+ connections and when reach in 100~150 it just don't accept more connections. My server is an game server.

Here is my code: https://pastebin.com/Tr7gajmN

https://pastebin.com/Fn3WnQ1N

[StormHub]

from https://pastebin.com/Fn3WnQ1N ChildServerWorkers = new MultithreadEventLoopGroup(1);

You are using ONE thread to handle all client connection tasks! If you are serving large amount of client connections, you'd better use multiple threads(event loops).

// This will spawn threads equal to the number of CPU cores ChildServerWorkers = new MultithreadEventLoopGroup();

[nayato]

@darkinghb considering there's a good amount of unknown code in here, any chance something there might be blocking? That might explain stalls or unnaturally low throughput.

[caozhiyuan]

it better run a task handle request in channleread.

[pvictorlv]

@StormHub I've changed to 8, but same thing, when i don't limit it, it use 100% cpu, any idea?

[StormHub]

@darkinghb It is recommended to be the same as number of CPUs (default). BTW: Whats the platform you are running on? There are a few things you can try set the backlog to 8192 might help a bit. And whats the actually SoRcvbuf value (GameSocketManagerStatics.BufferSize) The CPU busy probably is caused by large number of task wait spins (but you need to profile to know for sure)

[pvictorlv]

I'm running on windows server 2016 (.net 4.7, cpu xeon 10x2.6ghz), i can post here profile tests later (at night), i'll set the backlog and increase the limit of MultithreadEventLoopGroup and test.

[pvictorlv]

the buffersize is 8192

[nayato]

@darkinghb if CPU is a bottleneck - profile. Check PerfView. It will give you enough of an insight into the situation. I'm quite positive DotNetty can handle 100K connections on a single VM with no problem (given traffic is small over most of them).

[nayato]

Closing for the lack of updates. Feel free to reopen if there's further concern with this.