High Tq values for HAProxy
High Tq times are not always indicative of a problem, is http-server-close
set?
As per the documentation:
Setting "option http-server-close" may display larger request times since "Tq" also measures the time spent waiting for additional requests.
For example, this is set for Stack Overflow, and as some example data, the follow query:
Select Top 20 Tq from LogsLastTwoDays WITH (NoLOCK) WHERE
CreationDate > DATEADD(minute, -5, GETUTCDATE()) AND
ResponseCode = 200 AND Host = 'stackoverflow.com'
ORDER by Tq DESC
Yields:
Tq
-----
14990
14987
14986
14983
14974
14972
14972
14965
14964
14964
14962
14961
14960
14955
14952
14951
14945
14943
14935
14932
This is because with http-server-close
, the connection is kept open to the client (a persistent connection) for up to timeout http-keep-alive 15s
in our environment.
I usually focus on Tr
first, because that shows the response time between the LB and the server.
Pasting your configuration somewhere could help.
This could be related to timeout configuration and to HTTP mode as well. As Kyle mentionned I would have vote for the http-server-close option first. Since you have not enable it, you might be be under a slow-loris like attack.
Could you setup a "timeout http-request" parameter to 5s and see if you still have those line or if they are replaced by a 408 response ?
cheers