Radware Session And Dispatch Method

Dispatch Method	Method used to determine to which server traffic is directed: Cyclic — Directs traffic to each operational server one by one (round robin). Weighted Cyclic — This method uses the Weighted Round Robin algorithm. AppDirector distributes clients’ requests for service in the round robin manner taking into consideration the weight of servers in that farm. Explicitly, every new session is distributed to the next server up to the server weight. For example, if one server has a weight of 2 and another server has weight of 5, the first two sessions are sent to #1, the next five are sent to #2. Sessions eight and nine are sent to #1 again, and ten to fourteen are sent to #1 and so on. Least Amount of Traffic — Directs traffic to server with least traffic belonging to this farm. Server weights are also considered. Fewest Number of Users — Directs traffic to server with least amount of users belonging to this farm. Server weights are also considered. Least Amount of Traffic Local — Directs users to the server with the least traffic belonging to this farm. Server weights are also considered, but only for those servers in this farm. Fewest Number of Users Local — Directs users to the server with the fewest users. Server weights are also considered, but only for those servers in this farm. nt-1 —  AppDirector queries the farm's servers for Windows NT SNMP statistics and redirects new sessions to the least busy server according to the servers' reported statistics. nt-2 — Similar to nt-1, but using the second weights scheme.
Dispatch Method (continued)	private-1  — AppDirector queries the farm's servers for private SNMP parameters, as defined in the first private weights scheme. Ratios of users on servers are balanced according to reported statistics. private-2 — Similar to private-1, but using second weights scheme. Response Time — Enables Response Time load balancing. This load balances the servers in the farm based on the least loaded server as calculated by the Response Level. Server weights are also considered. Note: You need to create a health check that also measures response time, for each server, to have the response time dispatch method working properly. See Binding. Hashing  — AppDirector selects a server for a session using a static hash function. This method enables AppDirector to repeatedly direct requests from the same client to the same server within a farm even after the client entry has aged, as long as the server is still in service. This dispatch method also provides support for reverse proxy Web farms, avoiding data replication among the proxy servers. Input for the hash function is usually the Client IP address only. A formula is applied to this IP address. Output received is a numeric value. When the traffic is SIP, input for the hash function is either Call-ID or Request-URI (configurable) and when the traffic is RADIUS input for the hash function is a user-defined RADIUS attribute value. Note: When a hash result indicates to use a server with a status of Not in Service, the traffic to the failed server is spread across the remaining active servers in the farm.
Sessions Mode	The method used to handle new sessions: Regular  — All sessions from the same client IP address to the same service (VIP + Protocol + port) are forwarded to the same server. Entry Per Session — All sessions from the same client IP address to the same service (VIP + Protocol + port) are forwarded to the same server, but each session is recorded in the client table providing more accurate minimum-user load balancing. Server Per Session — Different sessions opened by a client IP address are served by different servers, according to load balancing algorithms. This enhances load balancing performance but may hinder some applications dependent on being served by the same server. It also may overload internal tables. Remove on Session End - EPS — After TCP client session ends, the client's entry is removed from the Client Table ends after 5-6 seconds. This enables Entry Per Session. Remove on Session End - SPS — After TCP client session ends, the client's entry is immediately removed from the Client Table after 5-6 seconds. This enables Server Per Session.