"Optimize the Network Kernel Parameters" setting may cause fluentd to fail to restart.

[migimigi]

Describe the bug

Sometimes when restarting fluentd I get the error "Address already in use - bind(2) for 0.0.0.0:24224".

Link to the problematic documentation

https://docs.fluentd.org/installation/before-install#optimize-the-network-kernel-parameters

Expected explanation

Explicitly reserve the ports used by fluentd using net.ipv4.ip_local_reserved_ports.

Additional context

I searched for binding failures and found a blog post about a similar situation.
Fluentd failed to start because of “Address already in use — bind(2) for 0.0.0.0:24224”
In this article, the author discovered that if the server socket port is in the ephemeral port range, the client socket may use that port as its src port.
As a solution, it is suggested to narrow the range of ephemeral ports, but this will reduce the number of available ports, so instead use net.ipv4.ip_local_reserved_ports to reserve the ports used by fluentd.

[migimigi]

Merged!