springcloud线上一个问题，当config-server连不上git时，微服务集群慢慢的都挂掉。
在入口层增加了日志跟踪问题：
org.springframework.cloud.config.server.environment.EnvironmentController.java
@RequestMapping("/{name}/{profiles}/{label:.*}")
public Environment labelled(@PathVariable String name, @PathVariable String profiles,
@PathVariable String label) {
if (name != null && name.contains("(_)")) {
// "(_)" is uncommon in a git repo name, but "/" cannot be matched
// by Spring MVC
name = name.replace("(_)", "/");
}
if (label != null && label.contains("(_)")) {
// "(_)" is uncommon in a git branch name, but "/" cannot be matched
// by Spring MVC
label = label.replace("(_)", "/");
}
StopWatch sw = new StopWatch("labelled");
sw.start();
logger.info("EnvironmentController.labelled()开始,name={},profiles={},label={}", name, profiles, label);
Environment environment = this.repository.findOne(name, profiles, label);
sw.stop();
logger.info("EnvironmentController.labelled()结束,name={},profiles={},label={},耗时={}毫秒,耗时={}秒", name, profiles, label, sw.getTotalTimeMillis(), sw.getTotalTimeSeconds());
return environment;
}健康检查的入口ConfigServerHealthIndicator.java增加日志：
@Override
protected void doHealthCheck(Health.Builder builder) throws Exception {
StopWatch sw = new StopWatch("doHealthCheck");
sw.start();
logger.info("ConfigServerHealthIndicator.doHealthCheck()开始,builder={}", builder);
builder.up();
List<Map<String, Object>> details = new ArrayList<>();
for (String name : this.repositories.keySet()) {
Repository repository = this.repositories.get(name);
String application = (repository.getName() == null)? name : repository.getName();
String profiles = repository.getProfiles(); try {
Environment environment = this.environmentRepository.findOne(application, profiles, repository.getLabel()); HashMap<String, Object> detail = new HashMap<>();
detail.put("name", environment.getName());
detail.put("label", environment.getLabel());
if (environment.getProfiles() != null && environment.getProfiles().length > 0) {
detail.put("profiles", Arrays.asList(environment.getProfiles()));
} if (!CollectionUtils.isEmpty(environment.getPropertySources())) {
List<String> sources = new ArrayList<>();
for (PropertySource source : environment.getPropertySources()) {
sources.add(source.getName());
}
detail.put("sources", sources);
}
details.add(detail);
} catch (Exception e) {
HashMap<String, String> map = new HashMap<>();
map.put("application", application);
map.put("profiles", profiles);
builder.withDetail("repository", map);
builder.down(e);
return;
}
}
builder.withDetail("repositories", details);
sw.stop();
logger.info("ConfigServerHealthIndicator.doHealthCheck()结束,耗时={}毫秒,耗时={}秒,builder={}", sw.getTotalTimeMillis(), sw.getTotalTimeSeconds(), builder);
}
通过耗时统计的日志分析后，发现是EnvironmentController和ConfigServerHealthIndicator调用次数太多，这两个调用最终会调用JGitEnvironmentRepository.fetch()方法，这个fetch方法会去请求git，超时时间大概是5秒。
由于请求的数量过多，服务请求不过来，线程阻塞了很长时间。
分析：
1、EnvironmentController的调用是每个微服务模块发起的，为什么？
2、ConfigServerHealthIndicator的调用是config-server的健康检查，可以通过设置检查的间隔时间缓解问题。
consul:
host: 10.200.110.100
port: 8500
enabled: true
discovery:
enabled: true
hostname: 10.200.110.100
healthCheckInterval: 30s
queryPassing: true
EnvironmentController的请求时用config-server的client端的健康检查发起的调用。看源码：
各个客户端在连接注册中心，获取到配置中心实例后，会调用上面这段代码逻辑从配置中心获取到 Environment数据变量，上线环境后，遇到了一个问题，查看日志，发现这块逻辑被不停的调用，每20多秒就会调用一次，application的name为 app,通过查看SpringCloudConfig的官方文档知道Config Server 通过一个健康指示器来检测配置的EnvironmentRepository是否正常工作。 默认情况下会向EnvironmentRepository询问一个名字为app的应用配置，EnvironmentRepository实例回应default配置。 也就是说当健康监视器默认开启的时候，会不停的调用findOne来检测，配置是否可用，是否会出现异常，
这段代码是org.springframework.cloud.config.server.config.ConfigServerHealthIndicator类里初始化名称为application名字为app的代码
@ConfigurationProperties("spring.cloud.config.server.health")
public class ConfigServerHealthIndicator extends AbstractHealthIndicator {
private EnvironmentRepository environmentRepository;
private Map<String, Repository> repositories = new LinkedHashMap<>();
public ConfigServerHealthIndicator(EnvironmentRepository environmentRepository) {
this.environmentRepository = environmentRepository;
}
@PostConstruct
public void init() {
if (this.repositories.isEmpty()) {
this.repositories.put("app", new Repository());
}
}
//...
}如果想停止掉这样的检测可以通过配置health.config.enabled=false去关闭此功能。
看源码：org.springframework.cloud.config.client.ConfigClientAutoConfiguration.java
@Configuration
public class ConfigClientAutoConfiguration {
@Configuration
@ConditionalOnClass(HealthIndicator.class)
@ConditionalOnBean(ConfigServicePropertySourceLocator.class)
@ConditionalOnProperty(value = "health.config.enabled", matchIfMissing = true)
protected static class ConfigServerHealthIndicatorConfiguration { @Bean
public ConfigServerHealthIndicator configServerHealthIndicator(
ConfigServicePropertySourceLocator locator,
ConfigClientHealthProperties properties, Environment environment) {
return new ConfigServerHealthIndicator(locator, environment, properties);
}
}
//...