Examples with CircuitBreakException com.github.df.restypass.exception.execute.CircuitBreakException used on opensource projects

Example 1 with CircuitBreakException

use of com.github.df.restypass.exception.execute.CircuitBreakException in project RestyPass by darren-fu.

the class RestyCommandExecutor method execute.

@Override
public Object execute(LoadBalancer lb, RestyCommand restyCommand) throws RestyException {
    if (restyCommand.getRestyCommandConfig().isForceBreakEnabled()) {
        throw new CircuitBreakException("circuit breaker is forced to open");
    }
    // 重试次数
    int retry = restyCommand.getRestyCommandConfig().getRetry();
    Object result = null;
    CircuitBreaker circuitBreaker = CircuitBreakerFactory.createDefaultCircuitBreaker(restyCommand.getServiceName());
    // RestyCommand ready to start
    restyCommand.ready(circuitBreaker);
    // 排除 彻底断路的server， 尝试过的server
    // 1.判断command使用的serverInstanceList是否存在被熔断的server
    // 1.1 存在的话 server加入 loadBalance 的excludeServerList
    Set<String> excludeInstanceIdSet = circuitBreaker.getBrokenServer();
    // 负载均衡器 选择可用服务实例
    ServerInstance serverInstance = lb.choose(serverContext, restyCommand, excludeInstanceIdSet);
    if (serverInstance == null) {
        throw new RuntimeException("no instances found:" + restyCommand.getServiceName() + ":" + serverContext.getServerList(restyCommand.getServiceName()));
    }
    // 重试机制
    for (int times = 0; times <= retry; times++) {
        try {
            boolean shouldPass = circuitBreaker.shouldPass(restyCommand, serverInstance);
            if (!shouldPass) {
                // fallback or exception
                throw new CircuitBreakException("circuit breaker is open");
            }
            RestyFuture future = restyCommand.start(serverInstance);
            RestyFuture futureArg = getFutureArg(restyCommand);
            if (restyCommand.isAsyncArg()) {
                // 直接返回null， 结果放入出参RestyFuture中
                return null;
            }
            if (restyCommand.isAsyncReturn()) {
                // 返回RestyFuture
                return future;
            }
            // 同步调用
            result = future.get();
            if (restyCommand.getStatus() == RestyCommandStatus.FAILED) {
                throw restyCommand.getFailException();
            }
            if (restyCommand.getStatus() == RestyCommandStatus.SUCCESS) {
                // 响应成功，无需重试了
                break;
            }
        } catch (Exception ex) {
            if (times == retry) {
                throw ex;
            } else {
                // 将本次使用的server 加入排除列表
                if (excludeInstanceIdSet == null || excludeInstanceIdSet == Collections.EMPTY_SET) {
                    excludeInstanceIdSet = new HashSet<>();
                }
                if (serverInstance != null) {
                    excludeInstanceIdSet.add(serverInstance.getInstanceId());
                }
                // 选择server， 如果没有server可选则无需重试，直接抛出当前异常
                serverInstance = lb.choose(serverContext, restyCommand, excludeInstanceIdSet);
                if (serverInstance == null || excludeInstanceIdSet.contains(serverInstance.getInstanceId())) {
                    throw ex;
                } else if (log.isDebugEnabled()) {
                    log.debug("请求切换服务实例重试:{}", serverInstance);
                }
            }
        }
    }
    return result;
}