How to set session expiration time in PHP _php tutorial

In the Apache and PHP environment, the default expiration time is about 20 minutes, then how we set the session expires, see the concrete method summarized below.

The most common thing we use in PHP programs is to set

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if (!isset ($_session[' last_access ')) | | (Time ()-$_session[' last_access ')) >60) $_session[' last_access '] = time (); ?>

This will be done, if you want to set the expiration, you can also in the program instance

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unset ($_session[' last_access ') or $_session[' last_access ']= '; ?>

The session has an outdated mechanism

Session.gc_maxlifetime Original session expiration is a small probability event, using session.gc_probability and Session.gc_divisor respectively to determine the probability of GC in the running session The default values for Session.gc_probability and session.gc_divisor are 1 and 100, respectively.

The probability of a GC in the session is 1%, respectively, by numerator and denominator. If you modify these two values, you will reduce the efficiency of PHP. So this method is wrong!!

Therefore, modifying the gc_maxlifetime variable in the php.ini file can prolong the session Expiration time: (for example, we change the expiration time to 86,400 seconds)

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Session.gc_maxlifetime = 86400

Then, restart your Web service (typically Apache).

When does the session "recycle" occur?

By default, every PHP request will have a 1/100 probability of recycling, so it might simply be understood as "one recovery per 100 PHP requests". This probability is controlled by the following parameters

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#概率是gc_probability/gc_divisor session.gc_probability = 1 Session.gc_divisor = 100

Note 1: Assuming this situation is gc_maxlifetime=120, if the last modification time of a session file is 120 seconds ago, the session will still be valid until the next recovery (1/100 probability) occurs.

NOTE 2: If your session uses Session.save_path to save the session,session recycle mechanism, it is possible that the expired session file will not be processed automatically. At this time need to regularly manually (or crontab) Delete expired session:cd/path/to/sessions; Find-cmin +24 | Xargs RM

http://www.bkjia.com/PHPjc/631569.html www.bkjia.com true http://www.bkjia.com/PHPjc/631569.html techarticle in the Apache and PHP environment, the default expiration time is about 20 minutes, then how we set the session expires, see the concrete method summarized below. Our most commonly used is in the PHP program set ...

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