Consistent Hash Site Selection

Feature description

[Analysis of Dubbo Consistent Hash Load Balancing Implementation](/zh/blog/2019/05/01/dubbo-%E4%B8%80%E8%87%B4%E6%80%A7hash%E8%B4%9F%E8 %BD%BD%E5%9D%87%E8%A1%A1%E5%AE%9E%E7%8E%B0%E5%89%96%E6%9E%90/)

scenes to be used

When there are multiple servers, the server is selected according to the consistent hashing of the request parameters.

How to use

There are many ways to configure consistent hashing, the most common are:

Annotation configuration

@DubboReference(loadbalance = “consistenthash”)

API configuration

referenceConfig.setLoadBalance(“consistenthash”);

Properties configuration

dubbo.reference.loadbalance=consistenthash

XML configuration

<dubbo:reference loadbalance=“consistenthash” />

By default, the first parameter is used as the hash key. If you need to switch parameters, you can specify the hash.arguments property

ReferenceConfig<DemoService> referenceConfig = new ReferenceConfig<DemoService>();
// ...init
Map<String, String> parameters = new HashMap<String, String>();
parameters. put("hash. arguments", "1");
parameters. put("sayHello. hash. arguments", "0,1");
referenceConfig.setParameters(parameters);
referenceConfig.setLoadBalance("consistenthash");
referenceConfig. get();