Another day, another fq issue (or user error).

I try to do the seeminlig simple task of downloading a single large file over local gigabit  LAN from a physical server running kernel 4.8 and sch_fq on intel server NICs.

For some reason it wouldn't go past around 25 MB/s. After having replaced SSL with no SSL, replaced apache with nginx and verified that there is plenty of bandwith available between my client and the server I tried to change qdisc from fq to pfifo_fast. It instantly shot up to around the expected 85-90 MB/s. The same happened with fq_codel in place of fq.

I then checked the statistics for fq and the throttled counter is increasing massively every second (eth0 and eth1 is LACPed using Linux bonding so both is seen here):

qdisc fq 8007: root refcnt 2 limit 10000p flow_limit 100p buckets 1024 orphan_mask 1023 quantum 3028 initial_quantum 15140 refill_delay 40.0ms

 Sent 787131797 bytes 520082 pkt (dropped 15, overlimits 0 requeues 0)

 backlog 98410b 65p requeues 0

  15 flows (14 inactive, 1 throttled)

  0 gc, 2 highprio, 259920 throttled, 15 flows_plimit

qdisc fq 8008: root refcnt 2 limit 10000p flow_limit 100p buckets 1024 orphan_mask 1023 quantum 3028 initial_quantum 15140 refill_delay 40.0ms

 Sent 2533167 bytes 6731 pkt (dropped 0, overlimits 0 requeues 0)

 backlog 0b 0p requeues 0

  24 flows (24 inactive, 0 throttled)

  0 gc, 2 highprio, 397 throttled

Do you have any suggestions?

Regards,

Hans-Kristian