Hi,
We are doing some basic testing using the TCP proxy app in stable-18.01 build.
When I proxy a single HTTP request for a 20MB file through to an Apache web
server I get less than one-tenth of the throughput compared to using a Linux
TCP Proxy (Apache Traffic Server) on exactly the same setup. The latency also
varies significantly between 1 and 3 seconds.
I've modified the fifo-size and rcv-buf-size and also the increased the TCP
window scaling which helps a bit but I still see a large difference.
Here is a sample output when running the test. The drops on the client-side
interface are a lot higher than on the server side - is that significant?
Is there any other tuning that I could apply?
show int addr
GigabitEthernet0/6/0 (up):
192.168.11.5/24
GigabitEthernet0/7/0 (up):
172.16.11.5/24
local0 (dn):
show int
Name Idx State Counter Count
GigabitEthernet0/6/0 1 up rx packets
5012
rx bytes
331331
tx packets
14813
tx bytes
21997981
drops
5008
ip4
5010
GigabitEthernet0/7/0 2 up rx packets
14688
rx bytes
21941197
tx packets
14680
tx bytes
968957
drops
12
ip4
14686
local0 0 down
show session verbose 2
Thread 0: 2 active sessions
[#0][T] 192.168.11.5:12000->192.168.11.4:37270 ESTABLISHED
flags: timers: [RETRANSMIT]
snd_una 18309357 snd_nxt 18443589 snd_una_max 18443589 rcv_nxt 96 rcv_las 96
snd_wnd 705408 rcv_wnd 524288 snd_wl1 96 snd_wl2 18309357
flight size 134232 send space 620 rcv_wnd_av 524288
cong none cwnd 134852 ssthresh 33244 rtx_bytes 0 bytes_acked 2856
prev_ssthresh 0 snd_congestion 5101145 dupack 0 limited_transmit 4135592144
tsecr 1408587266 tsecr_last_ack 1408587266
rto 200 rto_boff 0 srtt 1 rttvar 1 rtt_ts 1408587268 rtt_seq 177798749
tsval_recent 1403556248 tsval_recent_age 1
scoreboard: sacked_bytes 0 last_sacked_bytes 0 lost_bytes 0
last_bytes_delivered 0 high_sacked 164476297 snd_una_adv 0
cur_rxt_hole 4294967295 high_rxt 164406209 rescue_rxt 0
Rx fifo: cursize 0 nitems 524288 has_event 0
head 95 tail 95
ooo pool 0 active elts newest 4294967295
Tx fifo: cursize 272884 nitems 524288 has_event 1
head 483564 tail 232160
ooo pool 0 active elts newest 4294967295
[#0][T] 172.16.11.5:26485->192.168.200.123:80 ESTABLISHED
flags: timers: []
snd_una 96 snd_nxt 96 snd_una_max 96 rcv_nxt 18582241 rcv_las 18582241
snd_wnd 29056 rcv_wnd 229984 snd_wl1 18582185 snd_wl2 96
flight size 0 send space 4385 rcv_wnd_av 229984
cong none cwnd 4385 ssthresh 28960 rtx_bytes 0 bytes_acked 0
prev_ssthresh 0 snd_congestion 4132263094 dupack 0 limited_transmit 4132263094
tsecr 1408587264 tsecr_last_ack 1408587264
rto 200 rto_boff 0 srtt 1 rttvar 1 rtt_ts 0 rtt_seq 162704298
tsval_recent 1403552275 tsval_recent_age 2
scoreboard: sacked_bytes 0 last_sacked_bytes 0 lost_bytes 0
last_bytes_delivered 0 high_sacked 0 snd_una_adv 0
cur_rxt_hole 4294967295 high_rxt 0 rescue_rxt 0
Rx fifo: cursize 272884 nitems 524288 has_event 1
head 483564 tail 232160
ooo pool 0 active elts newest 4294967295
Tx fifo: cursize 0 nitems 524288 has_event 0
head 95 tail 95
ooo pool 0 active elts newest 4294967295
Regards,
Shaun
