LVS Scheduling algorithm

The main scheduling algorithm of LVS

• Polling scheduling

  The polling algorithm (RR) is to dispatch requests to different servers in a sequential way, and the most important feature of this algorithm is simple implementation. The polling algorithm assumes that all servers have the same ability to process requests, and the scheduler distributes all requests evenly to each real server.
  

• Weighted polling scheduling

  The weighted polling algorithm (WRR) is mainly an optimization and supplement to the polling algorithm, LVS will consider the performance of each server, and add a weight to each server, if the weight of server A is 1, Server B has a weight of 2, then the request dispatched to Server B is twice times the server A. The higher the weighted value of the server, the more requests are processed.
  

• Minimum connection scheduling

  The minimum connection scheduling algorithm (LC) dispatches the request to the smallest successive number of servers.
  

• Weighted minimum connection scheduling

  The weighted minimum connection algorithm (WLC) is a weighting to each server, and the scheduler maintains a balance between the number of server connections and the weights as much as possible.
  

• Minimal connections based on locality

  The least-connection scheduling algorithm based on locality (LBLC) is a scheduling algorithm for the target IP address of a request packet, which first finds the most recent destination IP address for all servers used by the target IP address of the request, if the server is still available and is capable of processing the request, The scheduler chooses the same server as much as possible, otherwise it will continue to select other viable servers.
  

• Minimum locality-based connections with replication

  With the complex local least-based connection algorithm (LBLCR) is not a target IP and a server connection between the record, he will maintain a target IP to a set of servers between the mapping relationship, to prevent the single-point server is too high.
  

• Target Address Hash Schedule

  The target address hash scheduling algorithm (DH) is also based on the destination IP address through the hash function of the target IP and the server to establish a mapping relationship, the server is unavailable or the load is too high, the request to the destination IP is fixed to the server.
  

• Source Address Hash Dispatch

  The source address hash scheduling algorithm (SH) is similar to the target address hash scheduling algorithm, but it is a static allocation of fixed server resources based on the source address hashing algorithm.
  

LVS Scheduling algorithm