nginx学习随笔--ssl_session_cache

nginx学习随笔–ssl_session_cache

英文原文：

Syntax: ssl_session_cache off | none | [builtin[:size]] [shared:name:size];
Default:    ssl_session_cache none;
Context:    http, server

Sets the types and sizes of caches that store session parameters. A cache can be of any of the following types:

off

the use of a session cache is strictly prohibited: nginx explicitly tells a client that sessions may not be reused.

none

the use of a session cache is gently disallowed: nginx tells a client that sessions may be reused, but does not actually store session parameters in the cache.

builtin

a cache built in OpenSSL; used by one worker process only. The cache size is specified in sessions. If size is not given, it is equal to 20480 sessions. Use of the built-in cache can cause memory fragmentation.

shared

a cache shared between all worker processes. The cache size is specified in bytes; one megabyte can store about 4000 sessions. Each shared cache should have an arbitrary name. A cache with the same name can be used in several virtual servers.

Both cache types can be used simultaneously, for example:

ssl_session_cache builtin:1000 shared:SSL:10m;

but using only shared cache without the built-in cache should be more efficient.

中文翻译：

设置存储session参数的缓存的类型和大小。缓存可以是下面任何一种类型：

off

严格禁止使用会话缓存：nginx明确告知客户端会话不可重用。

none

会话缓存是不允许的：nginx告知客户端会话可以重用，但并没有在缓存中存储会话参数。

builtin

在OpenSSL中构建缓存；只能被一个工作进程使用。缓存的大小在会话中指定，如果没有指定大小，默认20480个会话。使用内置缓存会导致内存碎片化。

shared

缓存在所有工作进程之间共享。缓存大小按照字节为单位指定；1MB可以存储4000个会话。每块共享内存都应该起个名字。同一块缓存可以在多个虚拟服务中使用。

两种类型的缓存可以同时使用：

ssl_session_cache builtin:1000 shared:SSL:10m;

但是，单独使用共享缓存会更有效。