![]() Requests for transactional information such as a discounted price can be routed to the application server responsible for managing pricing. So now a request for an image or video can be routed to the servers that store it and are highly optimized to serve up multimedia content. Layer 7 load balancing allows the load balancer to route a request based on information in the request itself, such as what kind of content is being requested. Over the course of the user’s session, he or she might request static content such as images or video, dynamic content such as a news feed, and even transactional information such as order status. It uses buffering to offload slow connections from the upstream servers, which improves performance.Ī device that performs Layer 7 load balancing is often referred to as a reverse‑proxy server. Layer 7 load balancing enables the load balancer to make smarter load‑balancing decisions, and to apply optimizations and changes to the content (such as compression and encryption). Layer 7 load balancing is more CPU‑intensive than packet‑based Layer 4 load balancing, but rarely causes degraded performance on a modern server. It then makes a new TCP connection to the selected upstream server (or reuses an existing one, by means of HTTP keepalives) and writes the request to the server. It can make a load‑balancing decision based on the content of the message (the URL or cookie, for example). A Layer 7 load balancer terminates the network traffic and reads the message within. Layer 7 load balancers route network traffic in a much more sophisticated way than Layer 4 load balancers, particularly applicable to TCP‑based traffic such as HTTP. HTTP is the predominant Layer 7 protocol for website traffic on the Internet. Layer 7 load balancing operates at the high‑level application layer, which deals with the actual content of each message. They can make limited routing decisions by inspecting the first few packets in the TCP stream. ![]() Layer 4 load balancers simply forward network packets to and from the upstream server without inspecting the content of the packets. Transmission Control Protocol (TCP) is the Layer 4 protocol for Hypertext Transfer Protocol (HTTP) traffic on the Internet. ![]() Layer 4 load balancing operates at the intermediate transport layer, which deals with delivery of messages with no regard to the content of the messages. Differences Between Layer 4 and Layer 7 Load Balancing Here we offer an overview of two load‑balancing options at two different layers in the model. Load balancing can be performed at various layers in the Open Systems Interconnection (OSI) Reference Model for networking. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |