spring boot的健康檢查HealthIndicators實戰(zhàn)

更新時間：2021年10月19日 12:13:09 作者：南北雪樹

這篇文章主要介紹了spring boot的健康檢查HealthIndicators實戰(zhàn)，具有很好的參考價值，希望對大家有所幫助。如有錯誤或未考慮完全的地方，望不吝賜教

springboot 健康檢查HealthIndicators

想提供自定義健康信息，你可以注冊實現(xiàn)了HealthIndicator接口的Spring beans。

你需要提供一個health()方法的實現(xiàn)，并返回一個Health響應(yīng)。

Health響應(yīng)需要包含一個status和可選的用于展示的詳情。

import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Component;
@Component
public class MyHealth implements HealthIndicator {
@Override
public Health health() {
int errorCode = check(); // perform some specific health check
if (errorCode != 0) {
return Health.down().withDetail("Error Code", errorCode).build();
} r
eturn Health.up().build();
}
}

除了Spring Boot預(yù)定義的Status類型，Health也可以返回一個代表新的系統(tǒng)狀態(tài)的自定義Status。

在這種情況下，需要提供一個HealthAggregator接口的自定義實現(xiàn)，或使用management.health.status.order屬性配置默認(rèn)的實現(xiàn)。

例如，假設(shè)一個新的，代碼為FATAL的Status被用于你的一個HealthIndicator實現(xiàn)中。為了配置嚴(yán)重程度，你需要將下面的配

置添加到application屬性文件中：

management.health.status.order: DOWN, OUT_OF_SERVICE, UNKNOWN, UP

如果使用HTTP訪問health端點，你可能想要注冊自定義的status，并使用HealthMvcEndpoint進(jìn)行映射。例如，你可以將

FATAL映射為HttpStatus.SERVICE_UNAVAILABLE。

springboot health indicator原理及其使用

作用

sping boot health 可以通過暴露的接口來提供系統(tǒng)及其系統(tǒng)組件是否可用。默認(rèn)通過/health來訪問。返回結(jié)果如下：

{
  "status": "UP",
  "discoveryComposite": {
    "description": "Spring Cloud Eureka Discovery Client",
    "status": "UP",
    "discoveryClient": {
      "description": "Spring Cloud Eureka Discovery Client",
      "status": "UP",
      "services": [
        "..."
      ]
    },
    "eureka": {
      "description": "Remote status from Eureka server",
      "status": "UP",
      "applications": {
        "AOMS-MOBILE": 1,
        "DATA-EXCHANGE": 1,
        "CLOUD-GATEWAY": 2,
        "AOMS": 1,
        "AOMS-AIIS": 0,
        "AOMS-EUREKA": 2
      }
    }
  },
  "diskSpace": {
    "status": "UP",
    "total": 313759301632,
    "free": 291947081728,
    "threshold": 10485760
  },
  "refreshScope": {
    "status": "UP"
  },
  "hystrix": {
    "status": "UP"
  }
}

狀態(tài)說明：

UNKNOWN：未知狀態(tài)，映射HTTP狀態(tài)碼為503
UP：正常，映射HTTP狀態(tài)碼為200
DOWN：失敗，映射HTTP狀態(tài)碼為503
OUT_OF_SERVICE：不能對外提供服務(wù)，但是服務(wù)正常。映射HTTP狀態(tài)碼為200

注意：UNKNOWN，DOWN，OUT_OF_SERVICE在為微服務(wù)環(huán)境下會導(dǎo)致注冊中心中的實例也為down狀態(tài)，請根據(jù)具體的業(yè)務(wù)來正確使用狀態(tài)值。

自動配置的Health Indicator

自動配置的HealthIndicator主要有以下內(nèi)容：

Key	Name	Description
cassandra	CassandraDriverHealthIndicator	Checks that a Cassandra database is up.
couchbase	CouchbaseHealthIndicator	Checks that a Couchbase cluster is up.
datasource	DataSourceHealthIndicator	Checks that a connection to DataSource can be obtained.
diskspace	DiskSpaceHealthIndicator	Checks for low disk space.
elasticsearch	ElasticsearchRestHealthIndicator	Checks that an Elasticsearch cluster is up.
hazelcast	HazelcastHealthIndicator	Checks that a Hazelcast server is up.
influxdb	InfluxDbHealthIndicator	Checks that an InfluxDB server is up.
jms	JmsHealthIndicator	Checks that a JMS broker is up.
ldap	LdapHealthIndicator	Checks that an LDAP server is up.
mail	MailHealthIndicator	Checks that a mail server is up.
mongo	MongoHealthIndicator	Checks that a Mongo database is up.
neo4j	Neo4jHealthIndicator	Checks that a Neo4j database is up.
ping	PingHealthIndicator	Always responds with UP.
rabbit	RabbitHealthIndicator	Checks that a Rabbit server is up.
redis	RedisHealthIndicator	Checks that a Redis server is up.
solr	SolrHealthIndicator	Checks that a Solr server is up.

分組

可以通過一個別名來啟用一組指標(biāo)的訪問。配置的格式如下：

management.endpoint.health.group.<name>
//demo:
management.endpoint.health.group.mysys.include=db,redis,mail
management.endpoint.health.group.custom.exclude=rabbit

如何管理Health Indicator

開啟

可以通過management.health.key.enabled來啟用key對應(yīng)的indicator。例如：

management.health.db.enabled=true

關(guān)閉

management.health.db.enabled=false

RedisHealthIndicator源碼解析

下面，通過RedisHealthIndicator源碼來為什么可以這么寫。

代碼結(jié)構(gòu)

自動配置的health indicator有HealthIndicator和HealthIndicatorAutoConfiguration兩部分組成。

HealthIndicator所在包在org.springframework.boot.actuate，

HealthIndicatorAutoConfiguration所在包在org.springframework.boot.actuate.autoconfigure下

//RedisHealthIndicator.java
public class RedisHealthIndicator extends AbstractHealthIndicator {
	static final String VERSION = "version";
	static final String REDIS_VERSION = "redis_version";
	private final RedisConnectionFactory redisConnectionFactory;
	public RedisHealthIndicator(RedisConnectionFactory connectionFactory) {
		super("Redis health check failed");
		Assert.notNull(connectionFactory, "ConnectionFactory must not be null");
		this.redisConnectionFactory = connectionFactory;
	}
	@Override
	protected void doHealthCheck(Health.Builder builder) throws Exception {
		RedisConnection connection = RedisConnectionUtils
				.getConnection(this.redisConnectionFactory);
		try {
			if (connection instanceof RedisClusterConnection) {
				ClusterInfo clusterInfo = ((RedisClusterConnection) connection)
						.clusterGetClusterInfo();
				builder.up().withDetail("cluster_size", clusterInfo.getClusterSize())
						.withDetail("slots_up", clusterInfo.getSlotsOk())
						.withDetail("slots_fail", clusterInfo.getSlotsFail());
			}
			else {
				Properties info = connection.info();
				builder.up().withDetail(VERSION, info.getProperty(REDIS_VERSION));
			}
		}
		finally {
			RedisConnectionUtils.releaseConnection(connection,
					this.redisConnectionFactory);
		}
	}
}

主要實現(xiàn)doHealthCheck方法來實現(xiàn)具體的判斷邏輯。注意，操作完成后在finally中釋放資源。

在父類AbstractHealthIndicator中，對doHealthCheck進(jìn)行了try catch,如果出現(xiàn)異常，則返回Down狀態(tài)。

 //AbstractHealthIndicator.java
 @Override
 public final Health health() {
  Health.Builder builder = new Health.Builder();
  try {
   doHealthCheck(builder);
  }
  catch (Exception ex) {
   if (this.logger.isWarnEnabled()) {
    String message = this.healthCheckFailedMessage.apply(ex);
    this.logger.warn(StringUtils.hasText(message) ? message : DEFAULT_MESSAGE,
      ex);
   }
   builder.down(ex);
  }
  return builder.build();
 }

RedisHealthIndicatorAutoConfiguration完成RedisHealthIndicator的自動配置

@Configuration
@ConditionalOnClass(RedisConnectionFactory.class)
@ConditionalOnBean(RedisConnectionFactory.class)
@ConditionalOnEnabledHealthIndicator("redis")
@AutoConfigureBefore(HealthIndicatorAutoConfiguration.class)
@AutoConfigureAfter({ RedisAutoConfiguration.class,
  RedisReactiveHealthIndicatorAutoConfiguration.class })
public class RedisHealthIndicatorAutoConfiguration extends
  CompositeHealthIndicatorConfiguration<RedisHealthIndicator, RedisConnectionFactory> {
 private final Map<String, RedisConnectionFactory> redisConnectionFactories;
 public RedisHealthIndicatorAutoConfiguration(
   Map<String, RedisConnectionFactory> redisConnectionFactories) {
  this.redisConnectionFactories = redisConnectionFactories;
 }
 @Bean
 @ConditionalOnMissingBean(name = "redisHealthIndicator")
 public HealthIndicator redisHealthIndicator() {
  return createHealthIndicator(this.redisConnectionFactories);
 }
}

重點說明ConditionalOnEnabledHealthIndicator:如果management.health..enabled為true,則生效。

CompositeHealthIndicatorConfiguration 中會通過HealthIndicatorRegistry注冊創(chuàng)建的HealthIndicator

自定義Indicator

@Component
@ConditionalOnProperty(name="spring.dfs.http.send-url")
@Slf4j
public class DfsHealthIndicator implements HealthIndicator {
    @Value("${spring.dfs.http.send-url}")
    private String dsfSendUrl;
    @Override
    public Health health() {
        log.debug("正在檢查dfs配置項...");
        log.debug("dfs 請求地址：{}",dsfSendUrl);
        Health.Builder up = Health.up().withDetail("url", dsfSendUrl);
        try {
            HttpUtils.telnet(StringUtils.getIpFromUrl(dsfSendUrl),StringUtils.getPortFromUrl(dsfSendUrl));
            return up.build();
        } catch (IOException e) {
            e.printStackTrace();
            log.error("DFS配置項錯誤或網(wǎng)絡(luò)超時");
            return up.withException(e).build();
        }
    }
}

返回值：

{
    "dfs": {
    "status": "UP",
    "url": "10.254.131.197:8088",
    "error": "java.net.ConnectException: Connection refused (Connection refused)"
    }
}

以上為個人經(jīng)驗，希望能給大家一個參考，也希望大家多多支持腳本之家。

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