Brocade ADX - LoadBalancing Methods

The Brocade ADX has a number of Load Balancing methods available. These are also known as predictors.


Predictors can be assigned on a global level or on a per virtual server basis. Below shows the syntax:

global              - server predictor [BALANCING METHOD]
virtual server   - server [BALANCING METHOD]


Below explains the various available predictor types:

Least Connections - The Brocade ADX sends the request to the real server that has the lowest total of active connections.
Round Robin - Each request is sent to the next real server. i.e Request 1 to RealServer1, Request 2 to RealServer2, Request 1 to RealServer1, Request 2 to RealServer2 and so on.
Weighted Round Robin - Metrics are assigned to each real server. Traffic is then distributed in a round robin fashion based on these metrics.
Example : Server A has a weight of 5 and Server B has weight of 7.
5 Connections would be sent to each server via a round robin basis and the final 2 would be sent to the second server.
Weighted - Each server is given a weight. Traffic is then distributed based on these weights.
Example : Total servers weight = 100 ; Server 1 has a weight of 10 so will get 10/100 of connections.
With the weighted predictor the full share of connections is sent to each real server sequentially i.e Server 1 gets the first 10 connections and so on.
Enhanced Weighted - Same as weighted but each servers connection share is distributed to each node on a per connection basis
Example : The server with the highest weight will receive the 1st connections, the server with the second highest weight will receive the next and so on.
Dynamic Weighted Predictor - Traffic is distributed using real time information (such as CPU, memory etc) which is retrieved via SNMP.
Dynamic-weighted Direct - Each SNMP response is assigned as a direct weight to each server. The server with the highest weight receives the higher percentage of connections.
Dynamic-weighted Reverse - Same as Direct by the server with the lowest weight receives the higher percentage of connections.