先確認(rèn)會(huì)話是否自動(dòng)開(kāi)啟還是需要通過(guò)session_start()來(lái)手動(dòng)開(kāi)啟：

　　; 指定會(huì)話模塊是否在請(qǐng)求開(kāi)始時(shí)自動(dòng)啟動(dòng)一個(gè)會(huì)話。默認(rèn)為 0(不啟動(dòng))

　　; Initialize session on request startup.

　　; http://php.net/session.auto-start

　　session.auto_start = 0

　　在客戶端，會(huì)話可以存儲(chǔ)在cookie或者通過(guò)URL參數(shù)來(lái)獲取。依賴于服務(wù)器的配置：

　　; 指定是否在客戶端用 cookie 來(lái)存放會(huì)話 ID。默認(rèn)為 1(啟用)

　　; Whether to use cookies.

　　; http://php.net/session.use-cookies

　　session.use_cookies = 1

　　; 指定是否在客戶端僅僅使用 cookie 來(lái)存放會(huì)話 ID。。啟用此設(shè)定可以防止有關(guān)通過(guò) URL 傳遞會(huì)話 ID 的攻擊。

　　; This option forces PHP to fetch and use a cookie for storing and maintaining

　　; the session id. We encourage this operation as it's very helpful in combatting

　　; session hijacking when not specifying and managing your own session id. It is

　　; not the end all be all of session hijacking defense, but it's a good start.

　　; http://php.net/session.use-only-cookies

　　session.use_only_cookies = 1

　　如果確認(rèn)存儲(chǔ)在cookie中，則可以進(jìn)一點(diǎn)配置會(huì)話存儲(chǔ)在cookie中的各項(xiàng)配置，如cookie_name，cookie_lifetime，cookie_path，cookie_domain，cookie_secure，cookie_httponly

　　; Name of the session (used as cookie name).

　　; http://php.net/session.name

　　session.name = PHPSESSID

　　; Lifetime in seconds of cookie or, if 0, until browser is restarted.

　　; http://php.net/session.cookie-lifetime

　　session.cookie_lifetime = 0

　　; The path for which the cookie is valid.

　　; http://php.net/session.cookie-path

　　session.cookie_path = /

　　; The domain for which the cookie is valid.

　　; http://php.net/session.cookie-domain

　　session.cookie_domain =

　　; Whether or not to add the httpOnly flag to the cookie, which makes it inaccessible to browser scripting languages such as JavaScript.

　　; http://php.net/session.cookie-httponly

　　session.cookie_httponly =

　　在服務(wù)器端，同樣也可以通過(guò)多種方式來(lái)存儲(chǔ)會(huì)話。默認(rèn)會(huì)話存儲(chǔ)在文件中，此時(shí)session.save_path為創(chuàng)建存儲(chǔ)文件的路徑。

　　; Handler used to store/retrieve data.

　　; http://php.net/session.save-handler

　　session.save_handler = files

　　; Argument passed to save_handler. In the case of files, this is the path

　　; where data files are stored. Note: Windows users have to change this

　　; variable in order to use PHP

　　's session functions.

　　;

　　; The path can be defined as:

　　;

　　; session.save_path = "N;/path"

　　;

　　; where N is an integer. Instead of storing all the session files in

　　; /path, what this will do is use subdirectories N-levels deep, and

　　; store the session data in those directories. This is useful if you

　　; or your OS have problems with lots of files in one directory, and is

　　; a more efficient layout for servers that handle lots of sessions.

　　;

　　; NOTE 1: PHP will not create this directory structure automatically.

　　; You can use the script in the ext/session dir for that purpose.

　　; NOTE 2: See the section on garbage collection below if you choose to

　　; use subdirectories for session storage

　　;

　　; The file storage module creates files using mode 600 by default.

　　; You can change that by using

　　;

　　; session.save_path = "N;MODE;/path"

　　;

　　; where MODE is the octal representation of the mode. Note that this

　　; does not overwrite the process's umask.

　　; http://php.net/session.save-path

　　;session.save_path = "/tmp"

　　PHP支持通過(guò)session_set_save_handler來(lái)實(shí)現(xiàn)會(huì)話處理器的自定義open, close, read, write, destroy, gc處理函數(shù)，常見(jiàn)的會(huì)話處理器包括使用內(nèi)存型分配(如mm，memcache等)，也可以使用數(shù)據(jù)庫(kù)進(jìn)行存儲(chǔ)。由此可見(jiàn)，若需要會(huì)話存儲(chǔ)與文件系統(tǒng)(例如用數(shù)據(jù)庫(kù)PostgreSQL Session Save Handler或默認(rèn)的文件存儲(chǔ)files)協(xié)同工作的，此時(shí)有可能造成用戶定制的會(huì)話處理器丟失了未存儲(chǔ)數(shù)據(jù)的會(huì)話。若使用內(nèi)存型分配存儲(chǔ)，又需要考慮會(huì)話持久化存儲(chǔ)問(wèn)題。

　　接下來(lái)重點(diǎn)講解memcache(d?)會(huì)話處理器。

　　Memcache模塊提供了于memcached方便的面向過(guò)程及面向?qū)ο蟮慕涌?，memcached是為了降低動(dòng)態(tài)web應(yīng)用 從數(shù)據(jù)庫(kù)加載數(shù)據(jù)而產(chǎn)生的一種常駐進(jìn)程緩存產(chǎn)品。

　　Memcache模塊同時(shí)提供了一個(gè)session 處理器 (memcache).

　　更多關(guān)于memcached的信息請(qǐng)參見(jiàn)» http://www.memcached.org/.

　　memcached是一個(gè)高性能分布式的內(nèi)存對(duì)象緩存系統(tǒng)， 通常被用于降低數(shù)據(jù)庫(kù)加載壓力以提高動(dòng)態(tài)web應(yīng)用的響應(yīng)速度。

　　此擴(kuò)展使用了libmemcached庫(kù)提供的api與memcached服務(wù)端進(jìn)行交互。它同樣提供了一個(gè)session處理器(memcached)。 它同時(shí)提供了一個(gè)session處理器(memcached)。

　　關(guān)于libmemcached的更多信息可以在» http://libmemcached.org/libMemcached.html查看。

　　memcache會(huì)話處理器配置：

　　session.save_handler = memcache

　　session.save_path = "tcp://127.0.0.1:11211?persistent=0&weight=1&timeout=1&retry_interval=15,tcp://127.0.0.1:11212?persistent=0&weight=1&timeout=1&retry_interval=15,tcp://127.0.0.1:11213?persistent=0&weight=1&timeout=1&retry_interval=15,tcp://127.0.0.1:11214?persistent=0&weight=1&timeout=1&retry_interval=15"