dnsdist: Change the default max number of queued TCP conns to 1000 #4596
I will check more carefully but it looks like there is a mistake in the way the maximum number of file descriptors is computed:
And dnsdist warns when the current FD limit is less than 4/3 of the maximum FD usage, since some FD can't be accurately predicted, like web and console connections. That formula doesn't work too well for large FD counts, I'm afraid.
With the existing default value of 0, we could consume an unlimited number of file descriptors if the queued connections kept piling up.