spring boot的健康检查HealthIndicators实战
springboot 健康检查HealthIndicators
想提供自定义健康信息，你可以注册实现了HealthIndicator接口的Spring beans。
你需要提供一个health()方法的实现，并返回一个Health响应。
Health响应需要包含一个status和可选的用于展示的详情。
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预定义的Status类型，Health也可以返回一个代表新的系统状态的自定义Status。
在这种情况下，需要提供一个HealthAggregator接口的自定义实现，或使用management.health.status.order属性配置默认的实现。
例如，假设一个新的，代码为FATAL的Status被用于你的一个HealthIndicator实现中。 为了配置严重程度， 你需要将下面的配
置添加到application属性文件中：
management.health.status.order: DOWN, OUT_OF_SERVICE, UNKNOWN, UP如果使用HTTP访问health端点， 你可能想要注册自定义的status， 并使用HealthMvcEndpoint进行映射。 例如， 你可以将
FATAL映射为HttpStatus.SERVICE_UNAVAILABLE。
springboot health indicator原理及其使用
作用
sping boot health 可以通过暴露的接口来提供系统及其系统组件是否可用。默认通过/health来访问。返回结果如下：
{
"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"
}
}状态说明：
UNKNOWN：未知状态，映射HTTP状态码为503UP：正常，映射HTTP状态码为200DOWN：失败，映射HTTP状态码为503OUT_OF_SERVICE：不能对外提供服务，但是服务正常。映射HTTP状态码为200
注意：UNKNOWN，DOWN，OUT_OF_SERVICE在为微服务环境下会导致注册中心中的实例也为down状态，请根据具体的业务来正确使用状态值。
自动配置的Health Indicator
自动配置的HealthIndicator主要有以下内容：
| 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. |
| 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. |
分组
可以通过一个别名来启用一组指标的访问。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
开启
可以通过management.health.key.enabled来启用key对应的indicator。例如：
management.health.db.enabled=true关闭
management.health.db.enabled=falseRedisHealthIndicator源码解析
下面，通过RedisHealthIndicator源码来为什么可以这么写。
代码结构
自动配置的health indicator有HealthIndicator和HealthIndicatorAutoConfiguration两部分组成。
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);
}
}
}
主要实现doHealthCheck方法来实现具体的判断逻辑。注意，操作完成后在finally中释放资源。
在父类AbstractHealthIndicator中，对doHealthCheck进行了try catch,如果出现异常，则返回Down状态。
//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的自动配置
@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);
}
}
重点说明ConditionalOnEnabledHealthIndicator:如果management.health..enabled为true,则生效。
CompositeHealthIndicatorConfiguration 中会通过HealthIndicatorRegistry注册创建的HealthIndicator
自定义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("正在检查dfs配置项...");
log.debug("dfs 请求地址：{}",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配置项错误或网络超时");
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)"
}
}以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程网。
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