private void printHealthyUpstream() {
        healthyUpstream.forEach((k, v) -> {
            if (Objects.nonNull(v)) {
                List<String> list = v.stream().map(Upstream::getUrl).collect(Collectors.toList());
                LOG.info("[Health Check] currently healthy upstream: {}", GsonUtils.getInstance().toJson(list));
            }
        });
    }
Print healthy and unhealthy check log.
shenyu-loadbalancer/src/main/java/org/apache/shenyu/loadbalancer/cache/UpstreamCheckTask.java