Load Balancer

effect ：

High availability Make the pressure of each equipment evenly distributed Support fault discovery and failover

classification ：

Hardware ：F5

Software ： nginx,haproxy

OSI 7 Layer model

Load balancing strategy ：

1. Polling strategy （ Default ）： Sit in rows and eat fruits , You take a bite and I take a bite

2. Weight strategy ：  I am fatter than you , I'll have ten

3.IP_HASH ：  A radish （IP) A pit , On request ip Come on hash Distribute to background server

4.URL_HASH ： A cabbage （URL) A pit , according to url Come on hash Distribute to background server

5：FAIR Which of you is idle , Come out and pick up the dung , Third party plug-ins need to be installed