huge number of persistent (idle) connections on loopback from mod_pagespeed

[Luke Kenneth Casson Leighton]

i'm running mod_status (to see what's going on) and there is a limit
on the number of processes (mpm_prefork) - mod_pagespeed seems to be
taking up pretty much absolutely all of them, with HTTP/1.0
connections. now, if they were HTTP/1.1 connections i would
understand (as they would be re-used). but if i am reading the stats
correctly the connections are open yet completely idle.

installed under debian:

ii mod-pagespeed-stable 1.12.34.2-r0 i386
Apache 2 module to optimize web content.
ii apache2 2.4.10-10+deb8u10 i386
Apache HTTP Server


SrvPIDAccMCPUSSReqConnChildSlotClientVHostRequest
1-0-0/0/618.0.1138900.00.0011.32::1127.0.0.1:80OPTIONS * HTTP/1.0
6-0-0/0/591.0.0093600.00.0013.71::1127.0.0.1:80OPTIONS * HTTP/1.0
8-0-0/0/641.0.0093500.00.0010.09::1127.0.0.1:80OPTIONS * HTTP/1.0
11-0-0/0/473.0.0093400.00.006.69::1127.0.0.1:80OPTIONS * HTTP/1.0
13-0-0/0/495.0.3593900.00.009.24::1127.0.0.1:80OPTIONS * HTTP/1.0
14-0-0/0/321.0.0093100.00.004.12::1127.0.0.1:80OPTIONS * HTTP/1.0
16-0-0/0/347.0.1892800.00.009.44::1127.0.0.1:80OPTIONS * HTTP/1.0
17-0-0/0/192.0.1692900.00.005.79::1127.0.0.1:80OPTIONS * HTTP/1.0
18-0-0/0/60.0.0093300.00.000.59::1127.0.0.1:80OPTIONS * HTTP/1.0
19-0-0/0/44.0.0093200.00.000.59::1127.0.0.1:80OPTIONS * HTTP/1.0
20-0-0/0/68.0.04537700.00.000.72::1127.0.0.1:80OPTIONS * HTTP/1.0
21-0-0/0/89.0.04534300.00.001.55::1127.0.0.1:80OPTIONS * HTTP/1.0
22-0-0/0/114.0.31535500.00.001.30::1127.0.0.1:80OPTIONS * HTTP/1.0
23-0-0/0/20.0.07530300.00.000.33::1127.0.0.1:80OPTIONS * HTTP/1.0
24-0-0/0/40.0.00538300.00.000.87::1127.0.0.1:80OPTIONS * HTTP/1.0
25-0-0/0/6.0.04534500.00.000.01::1127.0.0.1:80OPTIONS * HTTP/1.0
26-0-0/0/4.0.03537200.00.000.01::1127.0.0.1:80OPTIONS * HTTP/1.0
27-0-0/0/4.0.03537100.00.000.01::1127.0.0.1:80OPTIONS * HTTP/1.0
28-0-0/0/2.0.04538000.00.000.11::1127.0.0.1:80OPTIONS * HTTP/1.0
29-0-0/0/2.0.04538100.00.000.02::1127.0.0.1:80OPTIONS * HTTP/1.0
30-0-0/0/3.0.04534700.00.000.01::1127.0.0.1:80OPTIONS * HTTP/1.0
31-0-0/0/2.0.04537300.00.000.12::1127.0.0.1:80OPTIONS * HTTP/1.0
32-0-0/0/2.0.03537400.00.000.01::1127.0.0.1:80OPTIONS * HTTP/1.0
33-0-0/0/30.0.13480000.00.000.24::1127.0.0.1:80OPTIONS * HTTP/1.0
34-0-0/0/5.0.19534400.00.000.01::1127.0.0.1:80OPTIONS * HTTP/1.0
35-0-0/0/2.0.04537900.00.000.12::1127.0.0.1:80OPTIONS * HTTP/1.0
36-0-0/0/4.0.16535000.00.000.04::1127.0.0.1:80OPTIONS * HTTP/1.0
37-0-0/0/3.0.04533900.00.000.23::1127.0.0.1:80OPTIONS * HTTP/1.0
38-0-0/0/2.0.04537800.00.000.11::1127.0.0.1:80OPTIONS * HTTP/1.0
39-0-0/0/2.0.03537600.00.000.01::1127.0.0.1:80OPTIONS * HTTP/1.0
40-0-0/0/2.0.03537500.00.000.02::1127.0.0.1:80OPTIONS * HTTP/1.0
41-0-0/0/2.0.00534000.00.000.01::1127.0.0.1:80OPTIONS * HTTP/1.0
42-0-0/0/3.0.04533800.00.000.15::1127.0.0.1:80OPTIONS * HTTP/1.0
43-0-0/0/2.0.03536000.00.000.11::1127.0.0.1:80OPTIONS * HTTP/1.0
44-0-0/0/1.0.00539500.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
45-0-0/0/1.0.00539800.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
46-0-0/0/2.0.04536200.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
47-0-0/0/1.0.00539900.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
48-0-0/0/12.0.04534600.00.000.01::1127.0.0.1:80OPTIONS * HTTP/1.0
49-0-0/0/2.0.00536400.00.000.01::1127.0.0.1:80OPTIONS * HTTP/1.0
50-0-0/0/2.0.03535900.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
51-0-0/0/2.0.03534200.00.000.12::1127.0.0.1:80OPTIONS * HTTP/1.0
52-0-0/0/2.0.04534100.00.000.11::1127.0.0.1:80OPTIONS * HTTP/1.0
53-0-0/0/2.0.03536100.00.000.01::1127.0.0.1:80OPTIONS * HTTP/1.0
54-0-0/0/2.0.04536500.00.000.11::1127.0.0.1:80OPTIONS * HTTP/1.0
55-0-0/0/2.0.03536600.00.000.02::1127.0.0.1:80OPTIONS * HTTP/1.0
56-0-0/0/22.0.10479900.00.000.30::1127.0.0.1:80OPTIONS * HTTP/1.0
57-0-0/0/2.0.04536900.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
58-0-0/0/2.0.03536800.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
59-0-0/0/1.0.00540000.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
60-0-0/0/1.0.00539400.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
61-0-0/0/1.0.00539000.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
62-0-0/0/1.0.00539600.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
63-0-0/0/1.0.00539700.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
64-0-0/0/1.0.00539300.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
65-0-0/0/1.0.00538900.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
66-0-0/0/8.0.52531200.00.000.04::1127.0.0.1:80OPTIONS * HTTP/1.0
67-0-0/0/1.0.00538800.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
68-0-0/0/1.0.00538700.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
69-0-0/0/1.0.00539200.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
70-0-0/0/1.0.00539100.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
71-0-0/0/2.0.00535200.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0
72-0-0/0/1.0.00538600.00.000.00::1127.0.0.1:80OPTIONS * HTTP/1.0

[Luke Kenneth Casson Leighton]

On Sun, Aug 13, 2017 at 10:28 AM, Luke Kenneth Casson Leighton
<lk...@lkcl.net> wrote:

> i'm running mod_status (to see what's going on) and there is a limit
> on the number of processes (mpm_prefork) - mod_pagespeed seems to be
> taking up pretty much absolutely all of them, with HTTP/1.0
> connections. now, if they were HTTP/1.1 connections i would
> understand (as they would be re-used). but if i am reading the stats
> correctly the connections are open yet completely idle.

... i wasn't :) each line has a "-" in the PID column, indicating
that it was a past (historical) connection which mod_status seems to
keep around for some (useful) reason.

apologies!

l.