本文主要研究一下springboot的TomcatMetricsBinder
org/springframework/boot/actuate/autoconfigure/metrics/web/tomcat/TomcatMetricsAutoConfiguration.java
@Configuration(proxyBeanMethods = false)
@ConditionalOnWebApplication
@ConditionalOnClass({ TomcatMetrics.class, Manager.class })
@AutoConfigureAfter(CompositeMeterRegistryAutoConfiguration.class)
public class TomcatMetricsAutoConfiguration {
@Bean
@ConditionalOnBean(MeterRegistry.class)
@ConditionalOnMissingBean({ TomcatMetrics.class, TomcatMetricsBinder.class })
public TomcatMetricsBinder tomcatMetricsBinder(MeterRegistry meterRegistry) {
return new TomcatMetricsBinder(meterRegistry);
}
}
TomcatMetricsAutoConfiguration在CompositeMeterRegistryAutoConfiguration之后自动配置,它会创建TomcatMetricsBinder
org/springframework/boot/actuate/metrics/web/tomcat/TomcatMetricsBinder.java
public class TomcatMetricsBinder implements ApplicationListener, DisposableBean {
private final MeterRegistry meterRegistry;
private final Iterable tags;
private volatile TomcatMetrics tomcatMetrics;
public TomcatMetricsBinder(MeterRegistry meterRegistry) {
this(meterRegistry, Collections.emptyList());
}
public TomcatMetricsBinder(MeterRegistry meterRegistry, Iterable tags) {
this.meterRegistry = meterRegistry;
this.tags = tags;
}
@Override
public void onApplicationEvent(ApplicationStartedEvent event) {
ApplicationContext applicationContext = event.getApplicationContext();
Manager manager = findManager(applicationContext);
this.tomcatMetrics = new TomcatMetrics(manager, this.tags);
this.tomcatMetrics.bindTo(this.meterRegistry);
}
private Manager findManager(ApplicationContext applicationContext) {
if (applicationContext instanceof WebServerApplicationContext) {
WebServer webServer = ((WebServerApplicationContext) applicationContext).getWebServer();
if (webServer instanceof TomcatWebServer) {
Context context = findContext((TomcatWebServer) webServer);
return context.getManager();
}
}
return null;
}
private Context findContext(TomcatWebServer tomcatWebServer) {
for (Container container : tomcatWebServer.getTomcat().getHost().findChildren()) {
if (container instanceof Context) {
return (Context) container;
}
}
return null;
}
@Override
public void destroy() {
if (this.tomcatMetrics != null) {
this.tomcatMetrics.close();
}
}
}
TomcatMetricsBinder实现了ApplicationListener监听ApplicationStartedEvent,同时也实现了DisposableBean接口;其onApplicationEvent方法会获取applicationContext再获取tomcat的Manager,最后创建tomcatMetrics,然后执行bindTo方法;其close方法主要是执行tomcatMetrics的close方法
io/micrometer/core/instrument/binder/tomcat/TomcatMetrics.java
@NonNullApi
@NonNullFields
public class TomcatMetrics implements MeterBinder {
private static final String JMX_DOMAIN_EMBEDDED = "Tomcat";
private static final String JMX_DOMAIN_STANDALONE = "Catalina";
private static final String OBJECT_NAME_SERVER_SUFFIX = ":type=Server";
private static final String OBJECT_NAME_SERVER_EMBEDDED = JMX_DOMAIN_EMBEDDED + OBJECT_NAME_SERVER_SUFFIX;
private static final String OBJECT_NAME_SERVER_STANDALONE = JMX_DOMAIN_STANDALONE + OBJECT_NAME_SERVER_SUFFIX;
@Nullable
private final Manager manager;
private final MBeanServer mBeanServer;
private final Iterable tags;
private volatile String jmxDomain;
@Override
public void bindTo(MeterRegistry registry) {
registerGlobalRequestMetrics(registry);
registerServletMetrics(registry);
registerCacheMetrics(registry);
registerThreadPoolMetrics(registry);
registerSessionMetrics(registry);
}
//......
}
TomcatMetrics实现了MeterBinder接口,其bindTo方法主要是执行了registerGlobalRequestMetrics、registerServletMetrics、registerCacheMetrics、registerThreadPoolMetrics、registerSessionMetrics
private void registerGlobalRequestMetrics(MeterRegistry registry) {
registerMetricsEventually("type", "GlobalRequestProcessor", (name, allTags) -> {
FunctionCounter.builder("tomcat.global.sent", mBeanServer,
s -> safeDouble(() -> s.getAttribute(name, "bytesSent")))
.tags(allTags)
.baseUnit(BaseUnits.BYTES)
.register(registry);
FunctionCounter.builder("tomcat.global.received", mBeanServer,
s -> safeDouble(() -> s.getAttribute(name, "bytesReceived")))
.tags(allTags)
.baseUnit(BaseUnits.BYTES)
.register(registry);
FunctionCounter.builder("tomcat.global.error", mBeanServer,
s -> safeDouble(() -> s.getAttribute(name, "errorCount")))
.tags(allTags)
.register(registry);
FunctionTimer.builder("tomcat.global.request", mBeanServer,
s -> safeLong(() -> s.getAttribute(name, "requestCount")),
s -> safeDouble(() -> s.getAttribute(name, "processingTime")), TimeUnit.MILLISECONDS)
.tags(allTags)
.register(registry);
TimeGauge.builder("tomcat.global.request.max", mBeanServer, TimeUnit.MILLISECONDS,
s -> safeDouble(() -> s.getAttribute(name, "maxTime")))
.tags(allTags)
.register(registry);
});
}
registerGlobalRequestMetrics主要是注册了请求相关的指标
private void registerServletMetrics(MeterRegistry registry) {
registerMetricsEventually("j2eeType", "Servlet", (name, allTags) -> {
FunctionCounter.builder("tomcat.servlet.error", mBeanServer,
s -> safeDouble(() -> s.getAttribute(name, "errorCount")))
.tags(allTags)
.register(registry);
FunctionTimer.builder("tomcat.servlet.request", mBeanServer,
s -> safeLong(() -> s.getAttribute(name, "requestCount")),
s -> safeDouble(() -> s.getAttribute(name, "processingTime")), TimeUnit.MILLISECONDS)
.tags(allTags)
.register(registry);
TimeGauge.builder("tomcat.servlet.request.max", mBeanServer, TimeUnit.MILLISECONDS,
s -> safeDouble(() -> s.getAttribute(name, "maxTime")))
.tags(allTags)
.register(registry);
});
}
registerServletMetrics主要是注册了servlet相关的errorCount、requestCount及maxTime
private void registerCacheMetrics(MeterRegistry registry) {
registerMetricsEventually("type", "StringCache", (name, allTags) -> {
FunctionCounter.builder("tomcat.cache.access", mBeanServer,
s -> safeDouble(() -> s.getAttribute(name, "accessCount")))
.tags(allTags)
.register(registry);
FunctionCounter.builder("tomcat.cache.hit", mBeanServer,
s -> safeDouble(() -> s.getAttribute(name, "hitCount")))
.tags(allTags)
.register(registry);
});
}
registerCacheMetrics主要是注册了tomcat内部cache的accessCount、hitCount
private void registerThreadPoolMetrics(MeterRegistry registry) {
registerMetricsEventually("type", "ThreadPool", (name, allTags) -> {
Gauge.builder("tomcat.threads.config.max", mBeanServer,
s -> safeDouble(() -> s.getAttribute(name, "maxThreads")))
.tags(allTags)
.baseUnit(BaseUnits.THREADS)
.register(registry);
Gauge.builder("tomcat.threads.busy", mBeanServer,
s -> safeDouble(() -> s.getAttribute(name, "currentThreadsBusy")))
.tags(allTags)
.baseUnit(BaseUnits.THREADS)
.register(registry);
Gauge.builder("tomcat.threads.current", mBeanServer,
s -> safeDouble(() -> s.getAttribute(name, "currentThreadCount")))
.tags(allTags)
.baseUnit(BaseUnits.THREADS)
.register(registry);
});
}
registerThreadPoolMetrics主要是注册了tomcat线程池的相关指标
private void registerSessionMetrics(MeterRegistry registry) {
if (manager == null) {
// If the binder is created but unable to find the session manager don't register those metrics
return;
}
Gauge.builder("tomcat.sessions.active.max", manager, Manager::getMaxActive)
.tags(tags)
.baseUnit("sessions")
.register(registry);
Gauge.builder("tomcat.sessions.active.current", manager, Manager::getActiveSessions)
.tags(tags)
.baseUnit("sessions")
.register(registry);
FunctionCounter.builder("tomcat.sessions.created", manager, Manager::getSessionCounter)
.tags(tags)
.baseUnit("sessions")
.register(registry);
FunctionCounter.builder("tomcat.sessions.expired", manager, Manager::getExpiredSessions)
.tags(tags)
.baseUnit("sessions")
.register(registry);
FunctionCounter.builder("tomcat.sessions.rejected", manager, Manager::getRejectedSessions)
.tags(tags)
.baseUnit("sessions")
.register(registry);
TimeGauge.builder("tomcat.sessions.alive.max", manager, TimeUnit.SECONDS, Manager::getSessionMaxAliveTime)
.tags(tags)
.register(registry);
}
registerSessionMetrics主要是注册了tomcat的session相关指标
springboot的TomcatMetricsBinder主要是接收ApplicationStartedEvent然后创建TomcatMetrics执行bindTo进行注册,TomcatMetrics主要注册了globalRequest、servlet、cache、threadPool、session相关的指标。