Apache-2.4.27 massive slow down for files >8192 bytes long
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Apache2 Web Server |
Fix Released
|
Medium
|
|||
apache2 (Ubuntu) |
Fix Released
|
Undecided
|
Unassigned |
Bug Description
Tracking this down took forever + I believe I now have a test case.
Top priority, is finding a temporary fix for this problem.
Here's the symptom...
lxd: net12-david-favor # ab -vvv -k -t 10 -n 100000 -c 5 https:/
Document Length: 8192 bytes
Time taken for tests: 8.540 seconds
Failed requests: 0
Requests per second: 11710.24 [#/sec] (mean)
Time per request: 0.427 [ms] (mean)
Time per request: 0.085 [ms] (mean, across all concurrent requests)
ab -vvv -k -t 10 -n 100000 -c 5 https:/
Document Length: 8193 bytes
Time taken for tests: 10.087 seconds
Failed requests: 5
Requests per second: 1.19 [#/sec] (mean)
Time per request: 4202.710 [ms] (mean)
Time per request: 840.542 [ms] (mean, across all concurrent requests)
First run 1-8192 byte files work great. They serve fast with 0 failed requests.
Second run of 8193-... byte files slow to a crawl + produce request failures + notice the "Time taken for tests", which seems to relate to socket housekeeping tests, becomes very slow.
This seems to be an actual apache problem, rather than an ab problem, as all sites I host seem to slow down, when Apache2-4.27 is installed.
I'll setup a testbed system running Zesty, for which I can provide a login, for debugging, if required.
_______
lxd: net12-david-favor # uname -a
Linux net12-david-favor 4.8.0-30-generic #32-Ubuntu SMP Fri Dec 2 03:43:27 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
lxd: net12-david-favor # lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 16.10
Release: 16.10
Codename: yakkety
lxd: net12-david-favor # apt-cache policy apache2
apache2:
Installed: 2.4.27-
Candidate: 2.4.27-
Version table:
*** 2.4.27-
500 http://
100 /var/lib/
2.
500 http://
500 http://
2.
500 http://
Changed in apache2: | |
importance: | Unknown → Medium |
status: | Unknown → Confirmed |
Changed in apache2: | |
status: | Confirmed → Fix Released |
After a bit more testing, problem seems to be with ab.
Just compiled up https:/ /curl.haxx. se/libcurl/ c/chkspeed. html which produces this...
lxd: net12-david-favor # ./chkspeed https:/ /DavidFavor. com/foo- 8192.txt
Data downloaded: 8192 bytes.
Total download time: 0.089 sec.
Average download speed: 90.153 kbyte/sec.
lxd: net12-david-favor # ./chkspeed https:/ /DavidFavor. com/foo- 8193.txt
Data downloaded: 8193 bytes.
Total download time: 0.089 sec.
Average download speed: 89.793 kbyte/sec.
So same time for either 8192 or 8193 byte files, so looks like Apache-2.4.27 is working... whew...
Just ab is having some sort of problem.