Alibaba Cloud Load Balancer
First, the cause of the problem of excessive load
# 1. A sharp increase in the number of visits # 2. Most websites provide 24-hour service without interruption # 3. Compared with the development of network technology, the growth of server processing speed and memory access speed is far lower than that of network bandwidth and application Growth of services # 4. The traditional stand-alone model also often becomes a network failure point
Second, the server scale up and scale out
scale up
#Scale up (scale out) #Add hardware devices to a single node or upgrade it to a large node, such as increasing the memory, number of cores, etc. of the hardware of a single node #The advantage is that you do not need to change the business when expanding #The limitation is that you cannot Unlimited expansion
scale out
#Scale out (horizontal scaling) #Add more nodes and distribute data and workload among these nodes #The advantage is that it can be scaled without restrictions #The disadvantage is that it needs to be changed when expanding #Load balancing is achieved in this way
3. Load balancing
#Load Balance# The English name is Load Balance, which means that it is allocated to multiple operation units for execution, such as Web servers, FTP servers, enterprise key application servers and other mission-critical servers, so as to jointly complete work tasks # advantage # low cost scalability high reliability
4. Working principle
#Load balancing classifies the requests sent by the front end, and then distributes these classes to the responding servers according to certain rules
5. Basic functions