Programmatically changing Hystrix properties

Question

I have a circuit breaker set up that I would like to change parameters for runtime. Things like threads and timeout needs to be tuned at customer site.

I create a HystrixCommandProperties.Setter like this:

HystrixCommandProperties.Setter hystrixProps = 
    HystrixCommandProperties.defaultSetter()
        .withCircuitBreakerSleepWindowInMilliseconds(myconf.sleepWindow);
HystrixThreadPoolProperties.Setter threadPoolSettings = 
    HystrixThreadPoolProperties.Setter()
        .withCoreSize(myconf.threadPoolSize);

new MyCommand(HystrixCommand.Setter.withGroupKey("mygroup")
    .andCommandPropertiesDefaults(hystrixProps)
    .andThreadPoolPropertiesDefaults(threadPoolSettings));

MyCommand implements standard HystrixCommand and calls super(hystrixProps).

This works the first time, but when I try to change the properties at runtime (same group name) nothing happens. Is there another way to programmatically change this?

I don't want to go through the property files or specifying an URL to Archaius.

There are also answers that tells me to go through Archaius with ConfigurationManager.getConfigInstance().setProperty("...") . But surely there has to be a way that is similar to the original setters I create? Doing it completely different because it's the second time around just feels awkward.

Answer 1

There is a very simple way of doing this. It just needs 2 steps: a. registering the right plugin b. Adding the correct strategy with the required override.

Use-case: Override ExecutionTimeoutInMilliseconds to 30000 ms from 1000 ms

HystrixPlugins.getInstance().registerPropertiesStrategy(new HystrixPropertiesStrategy() {
            @Override
            public HystrixCommandProperties getCommandProperties(HystrixCommandKey commandKey, HystrixCommandProperties.Setter builder) {
                HystrixCommandProperties.Setter timeout
                        = HystrixCommandProperties.Setter().withExecutionTimeoutInMilliseconds(30000);
                return super.getCommandProperties(commandKey, timeout);
            }
        });

Here I am just overriding the required property. When you run your application you can see this in the DEBUG mode:

2018-06-08 23:18:32 [main] DEBUG c.n.h.s.p.HystrixPropertiesChainedProperty - Flipping property: hystrix.command.Client#getAllData().execution.isolation.thread.timeoutInMilliseconds to use its current value: 30000