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seen Oct 9 at 1:59

Nov
11
awarded  Popular Question
Jun
14
answered 200ms latency between TCP send and tcpdump only with large messages
Feb
10
comment 200ms latency between TCP send and tcpdump only with large messages
I read carefully the article but I think none of the cases is related because the 200ms delayed ACK timer goes off at 05.884715 when the last packet is received and is expired at 12.488688 when IBM MQ TCP send is called. Can you detail your 200ms delay scenario with the MQ send and tcpdump timestamps?
Feb
10
comment 200ms latency between TCP send and tcpdump only with large messages
As written in this question, I am aware that a TCP window larger than 1024 on the other side would shave about 10 milliseconds from latency. This question is about the 200ms latency between 12.488690 MQ send and 12.697572 TCP packet. Can the TCP behavior after 12.69757 explain this? The 200ms latency is always reproducible for large messages (e.g. 1138 bytes) and never reproducible for small messages (e.g. 512 bytes), both on test and production servers, and for months.
Feb
10
comment 200ms latency between TCP send and tcpdump only with large messages
If you refer to the 40-byte packet at 12:13:05.884718, which is in fact just a TCP header for ACK, it is much earlier than the next large packet at 12:13:12.697572. So why should they be consolidated?
Feb
9
comment 200ms latency between TCP send and tcpdump only with large messages
The 1138 bytes or 512 bytes in MQ trace are the full logical messages and are sent at once according to this same MQ trace. Anyway I don't understand how bigger messages could fix the latency issue since latency for small messages is fine. Where do you see a delayed ACK in tcpdump above? I don't see any. Your explanation doesn't seem to fit the tcpdump & MQ trace we get.
Feb
9
awarded  Analytical
Feb
8
awarded  Editor
Feb
8
revised 200ms latency between TCP send and tcpdump only with large messages
TCP timers link
Feb
8
awarded  Student
Feb
8
asked 200ms latency between TCP send and tcpdump only with large messages