问题
I use mod_fcgid and Xcache 3.0.3, PHP 5.4.18. I know that due to mod_fcgid design, I can't use a common shared memory, so every php-cgi process uses its own cache during its lifetime.
When I open top
and check for php-cgi
processes I see this:
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
14827 examplecom 20 0 230m 34m 18m S 11.0 3.4 0:07.07 php-cgi
14840 examplecom 20 0 242m 45m 18m S 0.7 4.6 0:02.74 php-cgi
14802 examplecom 20 0 237m 41m 18m S 6.3 4.2 0:11.39 php-cgi
14816 examplecom 20 0 232m 36m 18m S 1.7 3.7 0:07.75 php-cgi
14824 examplecom 20 0 231m 34m 18m S 8.6 3.5 0:06.12 php-cgi
14838 examplecom 20 0 229m 33m 17m S 0.7 3.3 0:00.89 php-cgi
14841 examplecom 20 0 228m 32m 18m S 2.0 3.3 0:01.71 php-cgi
14839 examplecom 20 0 228m 32m 18m R 8.6 3.2 0:01.58 php-cgi
Then I check XCache admin panel. Everytime I refresh admin page I see another process' data. For example I see that:
XCache Cacher
XCache Cacher Module enabled
Readonly Protection disabled
Page Request Time 2013-09-04 21:59:32
Cache Init Time 2013-09-04 21:59:05
Cache Instance Id 14827
Opcode Cache enabled, 12,582,912 bytes, 1 split(s), with 8192 slots each
Variable Cache enabled, 1,048,576 bytes, 1 split(s), with 8192 slots each
Shared Memory Schemes mmap
It seems like process 14827
lives for 27 seconds. But when I check top
that process works for 0:07.07.
So does PID 14827
lives for 7 minutes or 27 seconds. Which is correct or do I miss something with the XCache inner workings?
Is it better option to change /etc/httpd/conf.d/fcgid.conf
and make each process' lifetime longer ? Or is it bad idea to change default values.
What optimization can I do more to make XCache
and mod_fgid
work better ? (I don't prefer to change my server to nginx, and migrate to mod_fastcgi)
回答1:
I don't know XCache, but...
let's say we have 1 apache process 3 php processes
all 3 php processes are running. All 3 have same "running time". // time now is 0000
You request some page. Apache connect to process#1, cache is initiated. // cache init time is 0001
you refresh page. Apache connect to process#2, cache is initiated. // cache init time is 0033
Now you have 3 processes, all 3 are running since time 0000, but
process#1 have initCacheTime 0001
process#2 have initCacheTime 0033
process#3 do not have initatedCacheTime, cuz it is not used yet.
来源:https://stackoverflow.com/questions/18621883/mod-fcgid-processes-and-xcache-lifetime