Shulou(Shulou.com)06/03 Report--

In this issue, the editor will bring you about how to cooperate with the container for SpringBoot health examination. The article is rich in content and analyzes and describes for you from a professional point of view. I hope you can get something after reading this article.

Needless to say about the importance of monitoring, do not spend any more time in meetings to discuss its necessity, when you encounter problems online, you will no longer suspect that monitoring is a waste of development costs. Monitoring lets people say goodbye to the fire fighting status quo maintained by "guessing", and it can leave evidence to support our follow-up analysis.

As the primary goal of monitoring, the viability of the service, that is, its health, has become a top priority. SpringBoot can turn on health check with simple parameters and can be integrated with mainstream monitoring systems.

1. Monitoring on

In Spring, actuator components are used to do monitoring and other related operations. You can add the following starter to pom:

Org.springframework.boot spring-boot-starter-actuator

For gradle, add the following.

Dependencies {compile ("org.springframework.boot:spring-boot-starter-actuator")}

Visit / actuator/health to get the health status of the project.

{"status": "UP"}

In the application.yml file, add the following:

Management: endpoint: health: show-details: always

If you visit this interface again, you will output the details. Including the status of DB, disk status and so on. As you can see, the outermost status is actually a collection of internal component states.

{"status": "UP", "components": {"db": {"status": "UP", "details": {"database": "H2", "validationQuery": "isValid ()"}}, "diskSpace": {"status": "UP" "details": {"total": 250685575168, "free": 31373905920, "threshold": 10485760, "exists": true}}, "ping": {"status": "UP"}

two。 Custom Indicator

These functions are realized by Indicators (HealthIndicator). Such as the following:

DataSourceHealthIndicator

DiskSpaceHealthIndicator

CouchbaseHealthIndicator

MongoHealthIndicator

RedisHealthIndicator

CassandraHealthIndicator

If you are using the starter provided by the component, the Indicator will be aggregated in the / health interface, and if you do not want to monitor a component, you can turn it off in the configuration.

Management: health: mongo: enabled: false

With this in mind, when working on some components, you can provide the health check that comes with the component in this way: you only need to implement the HealthIndicator interface. The code example is as follows:

@ Component @ Slf4j public class X implements HealthIndicator {@ Override public Health health () {try {/ / check component status exception message} catch (Exception e) {log.warn ("Failed to connect to: {}", URL) Return Health.down () .withdetail ("error", e.getMessage ()) .build ();} return Health.up () .build ();}}

3. Access to the monitoring system

In more cases, we hope to collect the business monitoring data using professional monitoring components. This can be done in SpringBoot using micrometer.

Take the most popular prometheus as an example, add the following to pom.

Io.micrometer micrometer-registry-prometheus

Of course, we also need to configure some content in yaml. It now looks like this:

Management: endpoints: web: exposure: include: health,info,prometheus endpoint: health: show-details: always

At this point, visit / actuator/prometheus to obtain the monitoring data in prometheus format.

Similar to the following:

Jvm_memory_used_bytes {area= "heap", id= "PS Survivor Space",} 0.0 jvm_memory_used_bytes {area= "heap", id= "PS Old Gen",} 29.444904 million jvm_memory_used_bytes {area= "heap", id= "PS Eden Space",} 68.29 million jvm_memory_used_bytes {area= "nonheap", id= "Metaspace",} 59.17196 million jvm_memory_used_bytes {area= "nonheap", id= "Code Cache",} 10.929088 million jvm_memory_used_bytes {area= "nonheap" Id= "Compressed Class Space",} 8420512.0

On the target page of prometheus, you can see the following information:

Finally, in Grafana, it looks a little more flirtatious.

What can it monitor? Let's take a look:

Basic information of service nodes, including memory CPU, network IO, etc.

JVM stack information

JVM GC information, STW information

Connection pool information for default HikariCP

HTTP requests interface information (maximum time consuming, highest QPS)

Tomcat container monitoring

Logback log printing monitoring (number of entries at all levels)

... Other

As you can see, only by exposing such an interface, you can have a more comprehensive control of the components in the project.

4. Cooperate with the container

Finally, because of SpringBoot services, it is often published to containers, such as docker. At this point, use the probes configuration (kube has the same concept). Probes means probe and is used to distinguish between Liveness and Readiness.

The final configuration is as follows:

Management: health: probes: enabled: true endpoints: web: exposure: include: health,info,prometheus endpoint: health: show-details: always

At this point, we will get two groups in the browser's interface, as shown below:

Http://localhost:8080/actuator/health/liveness

Http://localhost:8080/actuator/health/readiness

These two links, the former is used to determine whether the container should be restarted, while the latter determines whether the service is available and, if available, will begin to accept external requests.

End

For small-scale SpringBoot applications, monitoring such as SpringBootAdmin is sufficient. But if your enterprise is centralized deployment, many nodes and frequent changes, a unified monitoring and construction platform is very necessary.

In addition to Prometheus,SpringBoot 's Metrics, the following components are supported:

AppOptics

Atlas

Datadog

Dynatrace

Elastic

Ganglia

Graphite

Humio

Influx

JMX

KairosDB

New Relic

Prometheus

SignalFx

Simple (in-memory)

Stackdriver

StatsD

Wavefront

This is how the SpringBoot health check shared by the editor cooperates with the container. If you happen to have similar doubts, please refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

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