Alan M. Carroll created TS-3442:
-----------------------------------

             Summary: Delay seen in handling the client's request while running 
with accept thread
                 Key: TS-3442
                 URL: https://issues.apache.org/jira/browse/TS-3442
             Project: Traffic Server
          Issue Type: Bug
          Components: Network
            Reporter: Alan M. Carroll


Recent tests prove that while using accept thread, we do end up waiting for a 
period of time before handling the request from the client.

It happens every 2 minutes if accept_thread is enabled with 1+ seconds delayed 
processing (accept -> 1+ seconds -> ats session born)
If accept_thread is disabled, it works fine.


Our test environment:
  client -> ats (ats-4.0.2_77 or ats-5.0.1_12) -> os (yapache, keep-alive off)

records.config
  CONFIG proxy.config.http.cache.http INT 0
  https://git.corp.yahoo.com/gist/sho/a23cf06a626bfa5d2041

plugin.config
  EMPTY

remap.config
  map http://scheduler.nevec.yahoo.com:4080/ 
http://b-sched1.ec.tw1.yahoo.com:4080/

Suspected tcpdump result:
Client to ATS
01:44:42.448130 IP 10.236.18.241.49306 > 10.236.3.123.4080: Flags [P.], seq 
1:822, ack 1, win 57, options [nop,nop,TS val 3868640125 ecr 2513718106], 
length 821
E..i(?@.=...
...
..{....]].A!*.....9.......
...}..KZGET /v1/scheduler/bid/job/187357436?rand=33918061510469269371075356787 
HTTP/1.1^M
Accept: */*^M
host:scheduler.nevec.yahoo.com:4080^M
…

ATS to Origin Server
01:44:44.642019 IP 10.236.3.123.44097 > 10.236.18.254.4080: Flags [P.], seq 
1:907, ack 1, win 57, options [nop,nop,TS val 2513722222 ecr 2932310262], 
length 906
E...G.@.@...
..{
....A..$...d......90......
..[n....GET /v1/scheduler/bid/job/187357436?rand=33918061510469269371075356787 
HTTP/1.1^M
Accept: */*^M
host:scheduler.nevec.yahoo.com:4080^M


Suspected debug log:
[Aug 21 01:44:44.355] Server {0x2b7527b80700} DEBUG: (http_cs) [40822] session 
born, netvc 0x2b753c01ee70
[Aug 21 01:44:44.357] Server {0x2b7527b80700} DEBUG: (http_cs) [40822] Starting 
transaction 1 using sm [40822]
[Aug 21 01:44:44.498] Server {0x2b7527d82700} DEBUG: (http_ss) [40822] session 
born, netvc 0x2b753c022590
[Aug 21 01:44:44.627] Server {0x2b7527b80700} DEBUG: (http)
+++++++++ Incoming Request +++++++++
-- State Machine Id: 40822
GET 
http://b-sched1.ec.tw1.yahoo.com:4080/v1/scheduler/bid/job/187357436?rand=33918061510469269371075356787
 HTTP/1.1^M
Accept: */*^M
host:scheduler.nevec.yahoo.com:4080^M

Bryan Call says - Besides the delay between the accept thread and the net 
thread, it looks like the client session is on one thread and the server 
session is on another. There might be some issue with a delay with running with 
a global server session pool.




--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to