SpringBoot 2.x 自定义注解annotation实现MicroMeter埋点

介绍

Micrometer 为 Java 平台上的性能数据收集提供了一个通用的 API，应用程序只需要使用 Micrometer 的通用 API 来收集性能指标即可。Micrometer 会负责完成与不同监控系统的适配工作。这就使得切换监控系统变得很容易。Micrometer 还支持推送数据到多个不同的监控系统。

在Springboot 2.X中，除了通过业务代码的方式埋点，官方也提供了@Timed，@Counted注解实现。

遗憾的是，官方对于自定义的Tag只做了简单的适配，不能满足我们一些自定义的指标需求。为了满足项目需求，所以我们需要自定义注解来实现MicroMeter的埋点。

依赖

除了基础的springboot依赖以外，我们还需要引入aop的依赖和actuator。actuator默认是依赖了micrometer，并通过micrometer对外提供endpoint。

        <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-aop</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId></dependency>

实践

这里我们以micrometer常见的Timer指标为例，自定义@Timed注解

自定义注解

为了更好的拓展官方定义的指标，直接沿用了一些官方的定义。针对Tag指标，我们做了单独的处理。

@Timed

@Target({ElementType.ANNOTATION_TYPE, ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface Timed {String value() default "";boolean longTask() default false;double[] percentiles() default {};boolean histogram() default false;String description() default "";
}

@Tag

@Target({ElementType.METHOD,ElementType.ANNOTATION_TYPE,ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Repeatable(value = Tags.class)
public @interface Tag {String key();String value();
}

@Tags

@Target({ElementType.METHOD,ElementType.ANNOTATION_TYPE,ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface Tags {Tag[] value();
}

类和接口

为了能支持自定义tag的解析，因此我们需要定义一个tag解析器。为了能更好的拓展，所以我们需要先定义一个接口

TagParser

public interface TagParser {/*** 获取tag解析器类型* @return*/String getType();/*** tag解析* @param tagDefinition tag定义* @param args 参数，包含：入参，返回值* @return* @throws JsonProcessingException*/Tag parse(TagDefinition tagDefinition, Object[] args) throws JsonProcessingException;
}

AbstractDefaultTagParser

AbstractDefaultTagParser存放公共的属性和方法

public abstract class AbstractDefaultTagParser implements TagParser {final static String POINT = ".";final static String REGEX_POINT = "\\.";final static String DEFAULT_TAG_VALUE = "None";@Overridepublic String getType() {return null;}@Overridepublic Tag parse(TagDefinition tagDefinition,Object[] args) throws JsonProcessingException {return null;}Integer regexParam(String regexString) {String reg = "[^0-9]";//Pattern类的作用在于编译正则表达式后创建一个匹配模式.Pattern pattern = Pattern.compile(reg);//Matcher类使用Pattern实例提供的模式信息对正则表达式进行匹配Matcher matcher = pattern.matcher(regexString);return Integer.parseInt(matcher.replaceAll("").trim());}
}

ArgTagParser

ArgTagParser 用于处理入参tag类型

public class ArgTagParser extends AbstractDefaultTagParser {public final static String ARG_TAG_PARSER_TYPE = "ARG";@Overridepublic String getType() {return ARG_TAG_PARSER_TYPE;}@Overridepublic Tag parse(TagDefinition tagDefinition, Object[] args) throws JsonProcessingException {if (null == args){return Tag.of(tagDefinition.getKey(),DEFAULT_TAG_VALUE);}String value = tagDefinition.getValue();Object arg;if (value.contains(POINT)) {String[] params = value.split(REGEX_POINT);arg = args[regexParam(params[0])];ObjectMapper objectMapper = new ObjectMapper();Map map = objectMapper.readValue(objectMapper.writeValueAsString(arg), Map.class);String param =  null == map.get(params[1]) ? DEFAULT_TAG_VALUE : objectMapper.writeValueAsString(map.get(params[1]));return Tag.of(tagDefinition.getKey(), param);}arg = args[regexParam(value)];return Tag.of(tagDefinition.getKey(),(String) arg);}
}

TagDefinition

TagDefinition存放Tag的定义信息

public class TagDefinition {private String type;private String key;private String value;public String getType() {return type;}public void setType(String type) {this.type = type;}public String getKey() {return key;}public void setKey(String key) {this.key = key;}public String getValue() {return value;}public void setValue(String value) {this.value = value;}
}

TimedAspect

@Timed注解切面,实现了自定义Tag处理逻辑。

@Slf4j
@Aspect
public class TimedAspect {public static final String DEFAULT_METRIC_NAME = "method.timed";public static final String DEFAULT_EXCEPTION_TAG_VALUE = "none";public static final String EXCEPTION_TAG = "exception";public static final String TAG_VALUE_ARG = "arg";public static final String TAG_VALUE_RESULT = "resultObj";private final MeterRegistry registry;private final Function<ProceedingJoinPoint, Iterable<Tag>> tagsBasedOnJoinPoint;public TimedAspect() {this(Metrics.globalRegistry);}public TimedAspect(MeterRegistry registry) {this(registry, pjp ->Tags.of("class", pjp.getStaticPart().getSignature().getDeclaringTypeName(),"method", pjp.getStaticPart().getSignature().getName()));}public TimedAspect(MeterRegistry registry, Function<ProceedingJoinPoint, Iterable<Tag>> tagsBasedOnJoinPoint) {this.registry = registry;this.tagsBasedOnJoinPoint = tagsBasedOnJoinPoint;}@Around("@annotation(com.seeyon.design.metrics.annotations.annotation.Timed)")public Object timedMethod(ProceedingJoinPoint pjp) throws Throwable {Method method = ((MethodSignature) pjp.getSignature()).getMethod();Timed timed = method.getAnnotation(Timed.class);com.seeyon.design.metrics.annotations.annotation.Tags tags = method.getAnnotation(com.seeyon.design.metrics.annotations.annotation.Tags.class);if (timed == null) {method = pjp.getTarget().getClass().getMethod(method.getName(), method.getParameterTypes());timed = method.getAnnotation(Timed.class);}final String metricName = timed.value().isEmpty() ? DEFAULT_METRIC_NAME : timed.value();final boolean stopWhenCompleted = CompletionStage.class.isAssignableFrom(method.getReturnType());if (!timed.longTask()) {return processWithTimer(pjp, timed, metricName, stopWhenCompleted, tags);} else {return processWithLongTaskTimer(pjp, timed, metricName, stopWhenCompleted, tags);}}private Object processWithTimer(ProceedingJoinPoint pjp, Timed timed, String metricName, boolean stopWhenCompleted, com.seeyon.design.metrics.annotations.annotation.Tags tags) throws Throwable {Object resultBody = null;Timer.Sample sample = Timer.start(registry);if (stopWhenCompleted) {try {return ((CompletionStage<?>) pjp.proceed()).whenComplete((result, throwable) ->record(pjp, timed, metricName, sample, getExceptionTag(throwable), tags, result));} catch (Exception ex) {record(pjp, timed, metricName, sample, ex.getClass().getSimpleName(), tags);throw ex;}}String exceptionClass = DEFAULT_EXCEPTION_TAG_VALUE;try {resultBody = pjp.proceed();return resultBody;} catch (Exception ex) {exceptionClass = ex.getClass().getSimpleName();throw ex;} finally {record(pjp, timed, metricName, sample, exceptionClass, tags, resultBody);}}private void record(ProceedingJoinPoint pjp, Timed timed, String metricName, Timer.Sample sample, String exceptionClass, com.seeyon.design.metrics.annotations.annotation.Tags tags) {record(pjp, timed, metricName, sample, exceptionClass, tags, null);}private void record(ProceedingJoinPoint pjp, Timed timed, String metricName, Timer.Sample sample, String exceptionClass, com.seeyon.design.metrics.annotations.annotation.Tags tags, Object resultBody) {try {sample.stop(Timer.builder(metricName).description(timed.description().isEmpty() ? null : timed.description()).tags(getExtraTags(pjp, tags, resultBody)).tags(EXCEPTION_TAG, exceptionClass).tags(tagsBasedOnJoinPoint.apply(pjp)).publishPercentileHistogram(timed.histogram()).publishPercentiles(timed.percentiles().length == 0 ? null : timed.percentiles()).register(registry));} catch (Exception e) {log.error("metrics timer error",e);}}private List<Tag> getExtraTags(ProceedingJoinPoint pjp, com.seeyon.design.metrics.annotations.annotation.Tags tags, Object resultBody) throws JsonProcessingException {List<Tag> tagList = new ArrayList<>();if (null == tags) {return tagList;}com.seeyon.design.metrics.annotations.annotation.Tag[] value = tags.value();List<TagDefinition> tagDefinitionList = new ArrayList<>();for (com.seeyon.design.metrics.annotations.annotation.Tag tag : value) {String key = tag.key();String param = tag.value();TagDefinition tagDefinition = new TagDefinition();tagDefinition.setKey(key);tagDefinition.setValue(param);if (param.startsWith(TAG_VALUE_ARG)) {tagDefinition.setType(ArgTagParser.ARG_TAG_PARSER_TYPE);} else if (param.startsWith(TAG_VALUE_RESULT)) {tagDefinition.setType(ResultObjTagParser.RESULT_TAG_PARSER_TYPE);}tagDefinitionList.add(tagDefinition);}Map<String, TagParser> beansOfType = BeanUtils.getBeansOfType(TagParser.class);for (Map.Entry<String, TagParser> parserEntry : beansOfType.entrySet()) {TagParser tagParser = parserEntry.getValue();Object[] args = null;for (TagDefinition tagDefinition : tagDefinitionList) {if (tagDefinition.getType().equals(tagParser.getType())) {if (tagParser.getType().equals(ArgTagParser.ARG_TAG_PARSER_TYPE)){args = pjp.getArgs();}else if (tagParser.getType().equals(ResultObjTagParser.RESULT_TAG_PARSER_TYPE)){if (null != resultBody){args = new Object[]{resultBody};}}Tag tag = tagParser.parse(tagDefinition, args);tagList.add(tag);}}}return tagList;}private String getExceptionTag(Throwable throwable) {if (throwable == null) {return DEFAULT_EXCEPTION_TAG_VALUE;}if (throwable.getCause() == null) {return throwable.getClass().getSimpleName();}return throwable.getCause().getClass().getSimpleName();}private Object processWithLongTaskTimer(ProceedingJoinPoint pjp, Timed timed, String metricName, boolean stopWhenCompleted, com.seeyon.design.metrics.annotations.annotation.Tags tags) throws Throwable {Optional<LongTaskTimer.Sample> sample = buildLongTaskTimer(pjp, timed, metricName, tags).map(LongTaskTimer::start);if (stopWhenCompleted) {try {return ((CompletionStage<?>) pjp.proceed()).whenComplete((result, throwable) -> sample.ifPresent(this::stopTimer));} catch (Exception ex) {sample.ifPresent(this::stopTimer);throw ex;}}try {return pjp.proceed();} finally {sample.ifPresent(this::stopTimer);}}private void stopTimer(LongTaskTimer.Sample sample) {try {sample.stop();} catch (Exception e) {// ignoring on purpose}}/*** Secure long task timer creation - it should not disrupt the application flow in case of exception*/private Optional<LongTaskTimer> buildLongTaskTimer(ProceedingJoinPoint pjp, Timed timed, String metricName, com.seeyon.design.metrics.annotations.annotation.Tags tags) {try {return Optional.of(LongTaskTimer.builder(metricName).description(timed.description().isEmpty() ? null : timed.description()).tags(getExtraTags(pjp, tags,null)).tags(tagsBasedOnJoinPoint.apply(pjp)).register(registry));} catch (Exception e) {return Optional.empty();}}}

使用

在需要监控的方法中首选标明监控类型，这里用@Timed作为监控指标记录。除了@Timed自带的属性以外，我们还额外定义了id和name2个指标，这2个指标也是定义在User实体类中的属性。

    @Timed(value = "timed.test.xiaoama",description = "timed metrics test for xiaoama")@Tags({@Tag(key = "id",value = "arg[0].id") , @Tag(key = "name",value = "arg[0].name")})public String doBusiness(User user){return "i am do business  service"+user.getId()+":"+user.getName();}

配置完成后，调用doBusiness方法，metrics指标就能收集到第三方的监控平台上，这里我们用的是Prometheus。登录Prometheus查看我们定义的指标，通过@Tag额外定义name和id字段也都被我们监控指标成功收集到。

counted_test_xiaoama_total{application="jk", class="com.xxx.jk.service.BusinessService", exception="none", id="12", instance="xxx.xx.xxx.xx:xxx", job="spring-actuator", method="doBusinessV2", name="xiaoama_12", result="i am do business service12:xiaoama_12"}