about the session temp file ?

cube316

when use the session functions,it will automaticly produce some temp file such as "sess_f649f4809654c1698570e1afb07d8777" untill session_destroy() is used or timeout

but ,something's not working correct !

i tried to set the php.ini as follows:

session.gc_probability = 1
session.gc_maxlifetime = 60

then write a php script which uses session ,but not include the "session_destroy()"

then,1 minutes later, I find the session file still there !

any explanations???

tha_mink

Garbage collection does not happen all the time. Your session file...if you called session_destroy() should be marked for garbage collection and deleted the next time php does gc. (your gc.probability is set to 1% so gc will only be started 1% of the time the session handler is called.) So long as you still can't USE the session and it's values are gone...I wouldn't worry about it. The session files will be cleaned up eventually. [they're tiny]

tha_mink

cube316

(your gc.probability is set to 1% so gc will only be started 1% of the time the session handler is called.)

you mean the gc_probability is calculated in percentage??

and i wonder whether session.gc_maxlifetime means milliseconds or just seconds?

adds on:
I haven't used the session_destroy() function,so the seesion temp file's still there

if this computer is used as an internet host,millions of session temp files will be left each day,how should i do about that ?
don't tell me to clean by hand 🙁

Weedpacket

Originally posted by cube316

you mean the gc_probability is calculated in percentage??

and i wonder whether session.gc_maxlifetime means milliseconds or just seconds?

My copy of php.ini reads (in part):


; Percentual probability that the 'garbage collection' process is started
; on every session initialization.
session.gc_probability = 1

; After this number of seconds, stored data will be seen as 'garbage' and
; cleaned up by the garbage collection process.
session.gc_maxlifetime = 1440

if this computer is used as an internet host,millions of session temp files will be left each day,how should i do about that ?
don't tell me to clean by hand 🙁

First of all, that's unlikely to happen - with a gc_probability of 1 percent, there is a 1/100 likelihood that any given PHP script execution will clean up all files more than gc_maxlifetime seconds old. And since you need at least one PHP script execution to create a session temp file, the chances that none of those millions of session-file-creating script executions will be that one in a hundred that does a clean up are pretty small (you can figure out the odds for yourself).

If you are that worried, up the gc probability - it means that each script startup will be slower (on average, while they check for old session files), but lowering the gc maxlifetime increases the risk of dropping someone's session while they're still using it.

cube316

"session.gc_probability = 1

session.gc_maxlifetime = 1440"

that's the default set of php.ini ,isn't it ?

i see , then how about set the gc_probability to a percent of 30 ?

any experience about the time delay ? (seams that you're an expert 🙂)

tha_mink

if this computer is used as an internet host,millions of session temp files will be left each day,how should i do about that ?
don't tell me to clean by hand

No actually if you think about it if there were a million sessions files being opened, the gc process would be kicked in 1/100 times and so it would clean out those temp files all the time. Consider this...1,000,000 hits per day is really about 11 hits per second. So the garbage collection process is going to start once about every 10 seconds. They would probably set the probability even lower than 1%. The gc process costs cpu cycles and disk I/O and so you only want to do it when it becomes necc.

Why worry about those little tiny temp files. They aren't hurting anyone.

BTW max lifetime is just a failsafe in case you don't call session_destroy(). There should be no reason to lower that as it will not really change the amount of session_tems_files you keep.

You will really notice a change in performance if you up the percentage to 30. I would leave it at 1%. Why are you so afraid of these harmless temp files. (so long as you don't have thousands of them)

cube316

Maybe a bit overworried(does this word exist ? i don't know exactly 🙂) about that , but ectually there are thousands of garbage everyday ,so i wonder if there is any good way to solve it.

Now i know what is going on , and won't do anything additional :p

Thanks for all of your help , indeed !

P.S:
a good place to practise my poor English , hope you can point out my syntax errors :p