Metrics

Cloud Monitoring

Cloud Monitoring provides visibility into the performance, uptime, and overall health of your applications. It can collect metrics, events, and metadata from Google Cloud, Amazon Web Services, hosted uptime probes, application instrumentation, Metrics data can be used to generate insights via dashboards, charts, and alerts. Cloud Monitoring alerting helps you collaborate by integrating with Slack, PagerDuty, and more.

Enable API

gcloud services enable monitoring.googleapis.com

Micrometer

Micrometer is the de-facto metrics collector for Spring Boot applications. Micrometer can export JVM metrics, Spring Boot metrics, and also application metrics with Counters, Gauges, and Timers. You can export the metrics to Cloud Monitoring with two methods:

Method

Description

When to use?

Prometheus

Export metrics using the Prometheus format from a Spring Boot Actuator endpoint (/actuator/prometheus).

A Prometheus agent will need to be configured to scrape the metrics.

Great option when running in Kubernetes, where metrics are usually collected using Prometheus operator.

Cloud Monitoring API

Export the metrics directly to Cloud Monitoring using the API.

This is needed whenever Prometheus scraping is not possible, such as Serverless environments like Cloud Run and App Engine.

Prometheus

Dependency

Add Spring Boot Actuator and Micrometer Prometheus dependencies:

Maven
Gradle
Maven
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>io.micrometer</groupId>
<artifactId>micrometer-registry-prometheus</artifactId>
</dependency>
Gradle
compile group: 'org.springframework.boot', name: 'spring-boot-starter-actuator'
compile group: 'io.micrometer', name: 'micrometer-registry-prometheus'

Configuration

Configure Spring Boot Actuator to expose the Prometheus endpoint:

application.properties
management.endpoints.web.exposure.include=health,info,prometheus

Notice that there is no explicit configuration for username/password. Cloud Trace authentication uses the GCP credential (either your user credential, or Service Account credential), and authorization is configured via Identity Access Management (IAM).

Prometheus Endpoint

You should be able to access the metrics in Prometheus format from /actuator/prometheus.

$ curl http://localhost:8080/actuator/prometheus
# HELP jvm_memory_committed_bytes The amount of memory in bytes that is committed for the Java virtual machine to use
# TYPE jvm_memory_committed_bytes gauge
jvm_memory_committed_bytes{area="nonheap",id="Code Cache",} 1.8284544E7
jvm_memory_committed_bytes{area="nonheap",id="Metaspace",} 6.6281472E7
jvm_memory_committed_bytes{area="nonheap",id="Compressed Class Space",} 8609792.0
jvm_memory_committed_bytes{area="heap",id="PS Eden Space",} 6.01358336E8
jvm_memory_committed_bytes{area="heap",id="PS Survivor Space",} 2.2020096E7
jvm_memory_committed_bytes{area="heap",id="PS Old Gen",} 1.1010048E8
# HELP tomcat_global_sent_bytes_total
...

Prometheus Scraper

If you are running in Kubernetes Engine, you can use Prometheus Operator to install a Prometheus instance. You also need to configure Prometheus with a sidecar that can propagate Prometheus metrics to Cloud Monitoring.

Install Prometheus Operator

kubectl apply -f \
https://raw.githubusercontent.com/coreos/prometheus-operator/v0.38.1/bundle.yaml

Provisioning Prometheus server with Sidecar

Create a prometheus.yaml for the Prometheus Operator, but replace the variables for ${RPOJECT_ID}, ${LOCATION}, and ${CLUSTER_NAME}with your Kubernetes Engine cluster information.

prometheus.yaml
# This config is cooked based on following resource:
# https://godoc.org/github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1#Prometheus
# https://github.com/istio/installer/blob/master/istio-telemetry/prometheus-operator/templates/prometheus.yaml
apiVersion: monitoring.coreos.com/v1
kind: Prometheus
metadata:
name: prometheus
labels:
spec:
image: "docker.io/prom/prometheus:v2.12.0"
version: v2.12.0
retention: 720h
scrapeInterval: 15s
serviceAccountName: prometheus
serviceMonitorSelector:
any: true
serviceMonitorNamespaceSelector:
any: true
podMonitorSelector:
any: true
podMonitorNamespaceSelector:
any: true
enableAdminAPI: false
podMetadata:
labels:
app: prometheus
containers:
- name: sd-sidecar
image: gcr.io/stackdriver-prometheus/stackdriver-prometheus-sidecar:0.7.3
args:
- --stackdriver.project-id=${PROJECT_ID}
- --stackdriver.kubernetes.location=${LOCATION}
- --stackdriver.kubernetes.cluster-name=${CLUSTER_NAME}
- --prometheus.wal-directory=/prometheus/wal
ports:
- name: sidecar
containerPort: 9091
volumeMounts:
- name: prometheus-prometheus-db
mountPath: /prometheus
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: prometheus
labels:
app: prometheus
rules:
- apiGroups: [""]
resources:
- nodes
- services
- endpoints
- pods
- nodes/proxy
verbs: ["get", "list", "watch"]
- apiGroups: [""]
resources:
- configmaps
verbs: ["get"]
- nonResourceURLs: ["/metrics"]
verbs: ["get"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: prometheus-default
labels:
app: prometheus
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: prometheus
subjects:
- kind: ServiceAccount
name: prometheus
namespace: default
---
apiVersion: v1
kind: Service
metadata:
name: prometheus
annotations:
prometheus.io/scrape: 'true'
labels:
app: prometheus
spec:
selector:
app: prometheus
ports:
- name: http-prometheus
protocol: TCP
port: 9090
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: prometheus
namespace: default
labels:
app: prometheus

Apply prometheus.yamlto the Kubernetes cluster to provision a new instance using the Prometheus Operator.

kubectl apply -f prometheus.yaml

Configure Prometheus server to scrape the metrics. Create a pod-monitors.yaml:

pod-monitors.yaml
apiVersion: monitoring.coreos.com/v1
kind: PodMonitor
metadata:
name: order-service
labels:
app: order-service
spec:
namespaceSelector:
any: true
selector:
matchLabels:
app: order-service
podMetricsEndpoints:
- targetPort: 8080
path: /actuator/prometheus
interval: 15s

Cloud Monitoring API

To export metrics directly to Cloud Monitoring, you can use the Micrometer Stackdriver registry.

Dependency

Add Spring Boot Actuator and Micrometer Stackdriver dependencies:

Maven
Gradle
Maven
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>io.micrometer</groupId>
<artifactId>micrometer-registry-stackdriver</artifactId>
</dependency>
Gradle
compile group: 'org.springframework.boot', name: 'spring-boot-starter-actuator'
compile group: 'io.micrometer', name: 'micrometer-registry-stackdriver'

Configuration

Configure the Project ID.

application.properties
management.metrics.export.stackdriver.project-id=<PROJECT_ID>

Better integration is coming soon with Spring Cloud GCP.

Learn More