前言
实际项目中，提供metrics接口，对接公司的监控系统，增加服务的可观察性，是一个基本的要求。在spring boot 1.X 中集成prometheus metrics，非常简单。但是spring boot 2.X 颇费周折。因为prometheus官方提供的prometheus-client-java不兼容spring boot 2.X 。需要借助micrometer。
步骤
1：引入所需的包
在pom.xml文件中增加如下:
org.springframework.boot
spring-boot-starter-actuator
io.micrometer
micrometer-core
io.micrometer
micrometer-registry-prometheus
2: 增加相关配置
在 application.yml中增加如下设置：
management:
endpoints:
web:
exposure:
include: ["metrics","prometheus"]
endpoint:
metrics:
enabled: true
prometheus:
enabled: true
metrics:
export:
prometheus:
enabled: true
PS: 如果想获取其他的metrics，可以设置include: ["*"]
3：运行查看metrics
运行项目，访问 http://localhost:8090/actuator，可看到如下：
{"_links":{"self":{"href":"http://localhost:8090/actuator","templated":false},"prometheus":{"href":"http://localhost:8090/actuator/prometheus","templated":false},"metrics-requiredMetricName":{"href":"http://localhost:8090/actuator/metrics/{requiredMetricName}","templated":true},"metrics":{"href":"http://localhost:8090/actuator/metrics","templated":false}}}PS:注意我的项目端口是8090。
由上可知，我们可以访问 http://localhost:8090/actuator/prometheus 获取prometheus格式的metrics。
具体如下：
# HELP system_load_average_1m The sum of the number of runnable entities queued to available processors and the number of runnable entities running on the available processors averaged over a period of time
# TYPE system_load_average_1m gauge
system_load_average_1m 3.12939453125
# HELP system_cpu_count The number of processors available to the Java virtual machine
# TYPE system_cpu_count gauge
system_cpu_count 8.0
# HELP system_cpu_usage The "recent cpu usage" for the whole system
# TYPE system_cpu_usage gauge
system_cpu_usage 0.11287867482465304
# HELP jvm_gc_pause_seconds Time spent in GC pause
# TYPE jvm_gc_pause_seconds summary
jvm_gc_pause_seconds_count{action="end of minor GC",cause="Allocation Failure",} 1.0
jvm_gc_pause_seconds_sum{action="end of minor GC",cause="Allocation Failure",} 0.014
# HELP jvm_gc_pause_seconds_max Time spent in GC pause
# TYPE jvm_gc_pause_seconds_max gauge
jvm_gc_pause_seconds_max{action="end of minor GC",cause="Allocation Failure",} 0.014
# HELP process_cpu_usage The "recent cpu usage" for the Java Virtual Machine process
# TYPE process_cpu_usage gauge
process_cpu_usage 2.803742769828689E-4
# HELP jvm_gc_memory_allocated_bytes_total Incremented for an increase in the size of the young generation memory pool after one GC to before the next
# TYPE jvm_gc_memory_allocated_bytes_total counter
jvm_gc_memory_allocated_bytes_total 1.73539328E8
# HELP process_uptime_seconds The uptime of the Java virtual machine
# TYPE process_uptime_seconds gauge
process_uptime_seconds 175.835
# HELP tomcat_sessions_active_current_sessions
# TYPE tomcat_sessions_active_current_sessions gauge
tomcat_sessions_active_current_sessions 0.0
# HELP tomcat_global_received_bytes_total
# TYPE tomcat_global_received_bytes_total counter
tomcat_global_received_bytes_total{name="http-nio-8090",} 0.0
# HELP tomcat_global_error_total
# TYPE tomcat_global_error_total counter
tomcat_global_error_total{name="http-nio-8090",} 0.0
# HELP tomcat_threads_current_threads
# TYPE tomcat_threads_current_threads gauge
tomcat_threads_current_threads{name="http-nio-8090",} 10.0
# 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="heap",id="PS Survivor Space",} 1.8874368E7
jvm_memory_committed_bytes{area="heap",id="PS Old Gen",} 1.63053568E8
jvm_memory_committed_bytes{area="heap",id="PS Eden Space",} 1.73539328E8
jvm_memory_committed_bytes{area="nonheap",id="Metaspace",} 5.505024E7
jvm_memory_committed_bytes{area="nonheap",id="Code Cache",} 1.114112E7
jvm_memory_committed_bytes{area="nonheap",id="Compressed Class Space",} 7602176.0
# HELP tomcat_sessions_expired_sessions_total
# TYPE tomcat_sessions_expired_sessions_total counter
tomcat_sessions_expired_sessions_total 0.0
# HELP tomcat_sessions_rejected_sessions_total
# TYPE tomcat_sessions_rejected_sessions_total counter
tomcat_sessions_rejected_sessions_total 0.0
# HELP jvm_threads_states_threads The current number of threads having NEW state
# TYPE jvm_threads_states_threads gauge
jvm_threads_states_threads{state="runnable",} 11.0
jvm_threads_states_threads{state="blocked",} 0.0
jvm_threads_states_threads{state="waiting",} 13.0
jvm_threads_states_threads{state="timed-waiting",} 5.0
jvm_threads_states_threads{state="new",} 0.0
jvm_threads_states_threads{state="terminated",} 0.0
# HELP tomcat_sessions_alive_max_seconds
# TYPE tomcat_sessions_alive_max_seconds gauge
tomcat_sessions_alive_max_seconds 0.0
# HELP jvm_threads_live_threads The current number of live threads including both daemon and non-daemon threads
# TYPE jvm_threads_live_threads gauge
jvm_threads_live_threads 29.0
# HELP tomcat_global_sent_bytes_total
# TYPE tomcat_global_sent_bytes_total counter
tomcat_global_sent_bytes_total{name="http-nio-8090",} 9114.0
# HELP jvm_gc_max_data_size_bytes Max size of old generation memory pool
# TYPE jvm_gc_max_data_size_bytes gauge
jvm_gc_max_data_size_bytes 0.0
# HELP jvm_memory_max_bytes The maximum amount of memory in bytes that can be used for memory management
# TYPE jvm_memory_max_bytes gauge
jvm_memory_max_bytes{area="heap",id="PS Survivor Space",} 1.8874368E7
jvm_memory_max_bytes{area="heap",id="PS Old Gen",} 2.863661056E9
jvm_memory_max_bytes{area="heap",id="PS Eden Space",} 1.392508928E9
jvm_memory_max_bytes{area="nonheap",id="Metaspace",} -1.0
jvm_memory_max_bytes{area="nonheap",id="Code Cache",} 2.5165824E8
jvm_memory_max_bytes{area="nonheap",id="Compressed Class Space",} 1.073741824E9
# HELP process_files_open_files The open file descriptor count
# TYPE process_files_open_files gauge
process_files_open_files 142.0
# HELP tomcat_sessions_active_max_sessions
# TYPE tomcat_sessions_active_max_sessions gauge
tomcat_sessions_active_max_sessions 0.0
# HELP jvm_threads_daemon_threads The current number of live daemon threads
# TYPE jvm_threads_daemon_threads gauge
jvm_threads_daemon_threads 25.0
# HELP tomcat_threads_config_max_threads
# TYPE tomcat_threads_config_max_threads gauge
tomcat_threads_config_max_threads{name="http-nio-8090",} 200.0
# HELP jvm_buffer_count_buffers An estimate of the number of buffers in the pool
# TYPE jvm_buffer_count_buffers gauge
jvm_buffer_count_buffers{id="direct",} 5.0
jvm_buffer_count_buffers{id="mapped",} 0.0
# HELP jvm_gc_memory_promoted_bytes_total Count of positive increases in the size of the old generation memory pool before GC to after GC
# TYPE jvm_gc_memory_promoted_bytes_total counter
jvm_gc_memory_promoted_bytes_total 8192.0
# HELP logback_events_total Number of error level events that made it to the logs
# TYPE logback_events_total counter
logback_events_total{level="warn",} 0.0
logback_events_total{level="debug",} 0.0
logback_events_total{level="error",} 0.0
logback_events_total{level="trace",} 0.0
logback_events_total{level="info",} 77.0
# HELP jvm_gc_live_data_size_bytes Size of old generation memory pool after a full GC
# TYPE jvm_gc_live_data_size_bytes gauge
jvm_gc_live_data_size_bytes 0.0
# HELP tomcat_global_request_seconds
# TYPE tomcat_global_request_seconds summary
tomcat_global_request_seconds_count{name="http-nio-8090",} 2.0
tomcat_global_request_seconds_sum{name="http-nio-8090",} 0.131
# HELP jvm_memory_used_bytes The amount of used memory
# TYPE jvm_memory_used_bytes gauge
jvm_memory_used_bytes{area="heap",id="PS Survivor Space",} 1.4836336E7
jvm_memory_used_bytes{area="heap",id="PS Old Gen",} 2.4336488E7
jvm_memory_used_bytes{area="heap",id="PS Eden Space",} 1.60499616E8
jvm_memory_used_bytes{area="nonheap",id="Metaspace",} 5.22724E7
jvm_memory_used_bytes{area="nonheap",id="Code Cache",} 1.0880512E7
jvm_memory_used_bytes{area="nonheap",id="Compressed Class Space",} 7006832.0
# HELP http_server_requests_seconds
# TYPE http_server_requests_seconds summary
http_server_requests_seconds_count{exception="None",method="GET",outcome="SUCCESS",status="200",uri="/actuator/prometheus",} 1.0
http_server_requests_seconds_sum{exception="None",method="GET",outcome="SUCCESS",status="200",uri="/actuator/prometheus",} 0.071661037
http_server_requests_seconds_count{exception="None",method="GET",outcome="SUCCESS",status="200",uri="/actuator",} 1.0
http_server_requests_seconds_sum{exception="None",method="GET",outcome="SUCCESS",status="200",uri="/actuator",} 0.026864224
# HELP http_server_requests_seconds_max
# TYPE http_server_requests_seconds_max gauge
http_server_requests_seconds_max{exception="None",method="GET",outcome="SUCCESS",status="200",uri="/actuator/prometheus",} 0.071661037
http_server_requests_seconds_max{exception="None",method="GET",outcome="SUCCESS",status="200",uri="/actuator",} 0.026864224
# HELP jvm_buffer_memory_used_bytes An estimate of the memory that the Java virtual machine is using for this buffer pool
# TYPE jvm_buffer_memory_used_bytes gauge
jvm_buffer_memory_used_bytes{id="direct",} 40960.0
jvm_buffer_memory_used_bytes{id="mapped",} 0.0
# HELP process_start_time_seconds Start time of the process since unix epoch.
# TYPE process_start_time_seconds gauge
process_start_time_seconds 1.556615678449E9
# HELP tomcat_threads_busy_threads
# TYPE tomcat_threads_busy_threads gauge
tomcat_threads_busy_threads{name="http-nio-8090",} 1.0
# HELP jvm_threads_peak_threads The peak live thread count since the Java virtual machine started or peak was reset
# TYPE jvm_threads_peak_threads gauge
jvm_threads_peak_threads 36.0
# HELP jvm_classes_loaded_classes The number of classes that are currently loaded in the Java virtual machine
# TYPE jvm_classes_loaded_classes gauge
jvm_classes_loaded_classes 10376.0
# HELP tomcat_sessions_created_sessions_total
# TYPE tomcat_sessions_created_sessions_total counter
tomcat_sessions_created_sessions_total 0.0
# HELP jvm_buffer_total_capacity_bytes An estimate of the total capacity of the buffers in this pool
# TYPE jvm_buffer_total_capacity_bytes gauge
jvm_buffer_total_capacity_bytes{id="direct",} 40960.0
jvm_buffer_total_capacity_bytes{id="mapped",} 0.0
# HELP tomcat_global_request_max_seconds
# TYPE tomcat_global_request_max_seconds gauge
tomcat_global_request_max_seconds{name="http-nio-8090",} 0.103
# HELP jvm_classes_unloaded_classes_total The total number of classes unloaded since the Java virtual machine has started execution
# TYPE jvm_classes_unloaded_classes_total counter
jvm_classes_unloaded_classes_total 1.0
# HELP process_files_max_files The maximum file descriptor count
# TYPE process_files_max_files gauge
process_files_max_files 10240.04: 自定义自己的metrics
在service层，编写具体的MetricsService，如下：
import com.scmp.scmpnotify.service.MetricsService;
import io.micrometer.core.instrument.Counter;
import io.micrometer.core.instrument.MeterRegistry;
import org.springframework.stereotype.Service;
@Service
public class MetricsService {
private final Counter sendSuccessCounter;
private final Counter sendFaileCounter;
MetricsServiceImpl(MeterRegistry registry) {
this.sendFaileCounter = Counter.builder("send_faile")
.description("send faile email total").register(registry);
this.sendSuccessCounter = Counter.builder("send_success")
.description("send success email total").register(registry);
}
public void sendSuccessIncrement(){
sendSuccessCounter.increment();
}
public void sendFaileIncrement(){
sendFaileCounter.increment();
}
}这里我们定义了两个counter 变量，分别统计发送成功和失败的消息数。
在controller层，
增加
@Autowired
private MetricsService metricsService;然后具体的逻辑中，直接使用 metricsService.sendSuccessIncrement()。
最后重新启动项目，再次访问：http://localhost:8090/actuator/prometheus 可看到自定义的metrics已经存在了。
如下：
...
# HELP send_success_total send success email total
# TYPE send_success_total counter
send_success_total 0.0
# HELP send_faile_total send faile email total
# TYPE send_faile_total counter
send_faile_total 0.0
...