The maximum number of connections is significantly lower than other brokers.

[xvjialing]

emqx能到19万,mochi-mqtt好像到8万左右就直接程序奔溃了

In a standalone setup on the same machine, the maximum number of connections is significantly lower than other brokers.

EMQX can handle up to 190,000 connections, while Mochi-MQTT crashes at around 80,000 connections.

[thedevop]

@xvjialing , can you check what caused the crash? I suspect it's due to Out Of Memory. I run brokers that handle hundreds of thousands clients without issue, but I have to adjust the server settings appropriate for the instance I use.

There are few settings for the broker that can significantly impacts the memory requirement with large number of connections:

1. ClientNetReadBufferSize
2. ClientNetWriteBufferSize
3. Capabilities.MaximumClientWritesPending (each connection will use 8 bytes * the value set for this), for large number of connections, lower this value significantly from the default. I use 128.
4. Also if you have long MaximumMessageExpiryInterval and MaximumSessionExpiryInterval, and often publish QOS > 0 messages to subscribers offline, then this can build up large memory usage as well.

Note, there are some here that can read/write Chinese, but many may not. You may receive more responses if you post your question in English.

Thanks @werbenhu for translating the title.