Resilix: A Fault Tolerance Library for Java and Springboot

1. Introduction

2. Usage Example

3. Configuration Guidelines

Introduction

This library provides some difference features compared to the others such as Resilience4j :

Resilix has 2 retry strategy. See Retry Strategy
Call rejection results in a ResultWrapper object, contrary with the other library like Resilience4j which will throw an CallNotPermittedException

if you have no concern with the retry and call rejection mechanism in Resilience4j, please use Resilience4j instead :) .

Usage Example

You can take a look at this demo project

<dependencies>
  ........................
  <dependency>
    <groupId>com.kruskal.resilix</groupId>
    <artifactId>resilix-springboot-v2</artifactId>
    <version>${resilix-version}</version>
  </dependency>
</dependencies>

@EnableResilix // add this to enable the auto configuration
@SpringBootApplication
public class ResilixDemoApplication {
  public static void main(String[] args) {
    SpringApplication.run(ResilixDemoApplication.class, args);
  }
}

@RestController public class DemoController {

  @Autowired private ResilixRegistry resilixRegistry;

  private final String[] thirdPartyList = {"foo", "bar"};


  @GetMapping("/resilix") public String callApi() {

    for (String thirdParty : thirdPartyList) {
      // get ResilixExecutor by the contextKey
      ResilixExecutor resilixExecutor = resilixRegistry.getResilixExecutor(thirdParty);

      try {
        ExecResult<String> execResult =
            resilixExecutor.executeChecked(() -> this.callThirdPartyApi(thirdParty));

        //will skip if not execution isn't permitted and return the result if it has been executed
        if (execResult.isExecuted())
          return execResult.getResult();
      } catch (Throwable e) {
        //continue to the next 3rd parties if there is any error occurred;
        log.error("{} execution failed", thirdParty, e);
      }
    }

    log.error("all third parties are down");
    throw new RuntimeException("all third parties are down");
  }

  /**
   * will watch the call's result(success/failure) for "somethingKey",
   * if there is an error, the error rate for "somethingKey" will be increased.
   */
  @ResilixWatcher(contextKey = "somethingKey") public Boolean callSomeMethod() {
    //do something
    return true;
  }
}

if you want to customize the configuration please read the Configuration Guidelines

Configuration Guidelines

Configuration example in application.properties:

# configuration for "foo"
kruskal.resilix.config.foo.errorThreshold=0.2
kruskal.resilix.config.foo.slidingWindowStrategy=COUNT_BASED
kruskal.resilix.config.foo.retryStrategy=PESSIMISTIC
kruskal.resilix.config.foo.waitDurationInOpenState=10000
kruskal.resilix.config.foo.slidingWindowMaxSize=10
kruskal.resilix.config.foo.numberOfRetryInHalfOpenState=5
kruskal.resilix.config.foo.minimumCallToEvaluate=2

# configuration for "bar"
kruskal.resilix.config.bar.errorThreshold=0.2
kruskal.resilix.config.bar.slidingWindowStrategy=COUNT_BASED
kruskal.resilix.config.bar.retryStrategy=OPTIMISTIC
kruskal.resilix.config.bar.waitDurationInOpenState=10000
kruskal.resilix.config.bar.slidingWindowMaxSize=10
kruskal.resilix.config.bar.numberOfRetryInHalfOpenState=5
kruskal.resilix.config.bar.minimumCallToEvaluate=2

kruskal.resilix.config.{your-key}.errorThreshold

Configures the error threshold in percentage in close state and half-open state (for retry process). when the error rate is greater or equal to the threshold, the circuit will trip to open state.

default value	`0.5`
possible value	from `0.0` to `1.0`

kruskal.resilix.config.{your-key}.slidingWindowStrategy

Configures the sliding-window aggregation type.

COUNT_BASED: aggregate error rate by the last n records.
TIME_BASED: aggregate error rate from the last t milliseconds.

default value	`COUNT_BASED`
possible value	`COUNT_BASED` or `TIME_BASED`

kruskal.resilix.config.{your-key}.slidingWindowMaxSize

Configures the maximum size for slidingWindowStrategy=COUNT_BASED

default value	`20`

kruskal.resilix.config.{your-key}.slidingWindowTimeRange

Configures the window time range for slidingWindowStrategy=TIME_BASED

default value	`15000` ms

kruskal.resilix.config.{your-key}.retryStrategy

Configures the retry strategy.

PESSIMISTIC: Do retry once at a time as long as the error threshold hasn't reached, and the retry limit (retryCountInHalfOpenState) hasn't exceeded.
OPTIMISTIC: Do retry as long as the error threshold hasn't reached, and the retry limit (retryCountInHalfOpenState) hasn't exceeded. it will result in more errors if multiple retries happened at the same time and get errors.

default value	`PESSIMISTIC`
possible value	`OPTIMISTIC` or `PESSIMISTIC`

kruskal.resilix.config.{your-key}.numberOfRetryInHalfOpenState

Configures the number of minimum retry in the half-open state before deciding which state it belongs to.

default value	`10`

kruskal.resilix.config.{your-key}.minimumCallToEvaluate

Configures the minimum records to be evaluated in sliding-window to prevent 100% error rate if the first call is failed.

default value	`10`

alfian853 / resilix