Connection Limit Issue with RabbitMQ at 65,000

[Yogie Prasetya]

Hi ,

I am experiencing an issue with RabbitMQ version 3.13 where the number of connections seems to be capped at 65,000. Despite having configured the kernel parameters and RabbitMQ settings, the limit persists.

Here are the steps I have taken so far:
- config on  /etc/security/limits.conf
* soft nproc 500000
* hard nproc 500000
* soft nofile 500000
* hard nofile 500000
root soft nproc 500000
root hard nproc 500000
root soft nofile 500000
root hard nofile 500000
rabbitmq soft nproc 500000
rabbitmq hard nproc 500000
rabbitmq soft nofile 500000
rabbitmq hard nofile 500000

- config kernel on /etc/sysctl.conf
net.ipv4.tcp_tw_reuse = 1
fs.file-max = 500000
net.core.rmem_max = 8738000
net.core.wmem_max = 6553600
net.ipv4.tcp_rmem = 4096 8738000 8738000
net.ipv4.tcp_wmem = 4096 6553600 6553600
net.ipv4.tcp_max_tw_buckets = 360000
net.ipv4.tcp_keepalive_time = 30
net.ipv4.tcp_keepalive_intvl = 30
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_syncookies = 0
net.ipv4.tcp_max_syn_backlog = 10000
net.ipv4.tcp_synack_retries = 3
net.ipv4.tcp_window_scaling = 1
net.ipv4.ip_local_port_range = 10000 64000
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
net.netfilter.nf_conntrack_max = 1048576

- rabbitmq.config

    {rabbit, [
        {frame_max, 500000},
        {tcp_listeners, [5672]},
        {vm_memory_high_watermark, 0.95},
        {vm_memory_high_watermark_paging_ratio, 0.75},
        {management_timeout, 1800000},
        {tcp_listen_options, [
            {backlog, 50000},
            {nodelay, true},
            {linger, {true, 0}},
            {exit_on_close, false}
        ]}
    ]}

Thanks for your help 

[jo...@cloudamqp.com]

Hi,

You need to increase ERL_MAX_PORTS, it was capped at 65536 in 3.11 [0].

You can learn more about that in this discussion [1].

/Johan

[0] https://github.com/rabbitmq/rabbitmq-server/blob/v3.11.x/release-notes/3.11.0.md#open-file-handle-limit-is-capped-by-default-on-linux-bsd-macos

[1] https://github.com/rabbitmq/rabbitmq-server/discussions/9311

[Yogie Prasetya]

Hi , 

Thanks for your help , its work and connection not capped at 65K 

Best Regards,