Architectural design: three modes of LVS

● NAT: network address translation mode

● DR: Direct routing mode

● Tuner: Tunnel mode

procedure

superiority

Is the simplest deployment, because there is no need to map and develop network addresses, only one repeater is needed.

deficient

LVS will become the performance bottleneck of the whole application cluster. The source request and corresponding response will be sent to LVS, and the mapping information and socket connection will be maintained after the packet is sent. When the network is abnormal, a single LVS device may not be able to bear the pressure.

procedure

superiority

For requests, LVS devices only care about the forwarding of requests. When receiving the network package of the client App, you can disconnect from the client App.

For the response, the back-end service cluster directly responds with the client App after processing the request.

For the connection, it can save the time of maintaining the socket connection at both ends.

deficient

LVS equipment can only use mac address translation protocol in the same computer room as the back-end service cluster, so the source IP address and the source mac address cannot be at the same level.

procedure

superiority

LVS and back-end service cluster do not need to be in the same computer room.

deficient

The back-end service cluster must support tunnel mode.

LVS/DR mode is the most widely used mode, because it can ensure the throughput of the system in the local area network, and it is not necessary to use tunnel mode across computer rooms unless it is originally deployed across computer rooms.