JonCole

Some of the Redis best practices content has moved

This content from this markdown file has moved a new, happier home where it can serve more people. Please check it out : https://docs.microsoft.com/azure/azure-cache-for-redis/cache-best-practices.

NOTE: Client specific guidance listed below is still valid and should still be considered. I will update this document once all content has been moved.

tuxfight3r

##TCP FLAGS##

Unskilled Attackers Pester Real Security Folks
==============================================
                     TCPDUMP FLAGS
Unskilled =  URG  =  (Not Displayed in Flag Field, Displayed elsewhere) 
Attackers =  ACK  =  (Not Displayed in Flag Field, Displayed elsewhere)
Pester    =  PSH  =  [P] (Push Data)
Real      =  RST  =  [R] (Reset Connection)
Security  =  SYN  =  [S] (Start Connection)

jcouyang

本文基本上这为两篇文章的翻译和整合 -- Scalable networking And Why are event-driven server so great

OPPC模型瓶颈

传统服务器模型如Apache为每一个请求生成一个子进程。当用户连接到服务器的一个子进程就产生，并处理连接。每个连接获得一个单独的线程和子进程。当用户请求数据返回时，子进程开始等待数据库操作返回。如果此时另一个用户也请求返回数据，这时就产生了阻塞。

这种模式在非常小的工作负荷是表现良好，当请求的数量变得太大是服务器会压力过于巨大。 当Apache达到进程的最大数量，所有进程都变得缓慢。每个请求都有自己的线程，如果服务代码使用PHP编写时，每个进程所需要的内存量是相当大的[1]。

fork()操作延时

lsbardel

#! /bin/sh
### BEGIN INIT INFO
# Provides:		redis-server
# Required-Start:	$syslog
# Required-Stop:	$syslog
# Should-Start:		$local_fs
# Should-Stop:		$local_fs
# Default-Start:	2 3 4 5
# Default-Stop:		0 1 6
# Short-Description:	redis-server - Persistent key-value db