一驳阎、Compile
編譯源碼請查看源碼中的文檔 How-to-build.md
-
首先確保你Maven的版本為3.6+捌议，然后源碼根目錄執(zhí)行下面命令
mvn clean package -DskipTests
-
編譯成功后，將工程導(dǎo)入到 IDEA中昏名，因為里面用到了proto泛释，默認情況下IDE是識別不到這些代碼的衫哥，如果你使用的是 IDEA工具圃伶，請安裝下面插件。
確保target目錄沒有被隱藏毙芜，如果隱藏了忽媒，可通過 Setting - Editor - File Types 將 target 清除
image-20210813162204334.png
二、OAP
OAP是SkyWalkingAgent 的服務(wù)端腋粥，啟動一個基于H2存儲簡單的OAP服務(wù)器晦雨，運行 oap-server/server-starter中OAPServerStartUp類。
可以看到OAPServerStartUp類又調(diào)用了一個 OAPServerBootstrap 的類隘冲，這個類才是真正的入口類闹瞧。
public class OAPServerStartUp {
public static void main(String[] args) {
OAPServerBootstrap.start();
}
}
OAPServerBootstrap.start()方法主要工作就是解析application.yml文件，加載配置展辞，初始化各個模塊奥邮。
public class OAPServerBootstrap {
public static void start() {
String mode = System.getProperty("mode");
RunningMode.setMode(mode);
ApplicationConfigLoader configLoader = new ApplicationConfigLoader();
ModuleManager manager = new ModuleManager();
try {
// 加載 application.yml 中的配置
ApplicationConfiguration applicationConfiguration = configLoader.load();
// 加載所有 Module 的實現(xiàn)類
manager.init(applicationConfiguration);
// 加載 Prometheus指標收集器
manager.find(TelemetryModule.NAME)
.provider()
.getService(MetricsCreator.class)
.createGauge("uptime", "oap server start up time", MetricsTag.EMPTY_KEY, MetricsTag.EMPTY_VALUE)
// Set uptime to second
.setValue(System.currentTimeMillis() / 1000d);
if (RunningMode.isInitMode()) {
log.info("OAP starts up in init mode successfully, exit now...");
System.exit(0);
}
} catch (Throwable t) {
log.error(t.getMessage(), t);
System.exit(1);
}
}
}
上面的 manager.init() 方法，加載模塊時罗珍，采用 Java SPI 機制洽腺，讀取每個模塊的 META-INF.services 下配置，獲取實現(xiàn)類靡砌。
注意：值為
-的模塊不會被加載已脓，例如下面模塊將不會被加載珊楼，如果不注意的話會讓你抓狂通殃。詳細請看我的文章 《Skywalking：定制化》node-exporter章節(jié)。prometheus-fetcher: selector: ${SW_PROMETHEUS_FETCHER:-}
public void init(
ApplicationConfiguration applicationConfiguration) throws ModuleNotFoundException, ProviderNotFoundException, ServiceNotProvidedException, CycleDependencyException, ModuleConfigException, ModuleStartException {
// 獲取所有可用模塊列表
String[] moduleNames = applicationConfiguration.moduleList();
// 加載ModuleDefine的實現(xiàn)類
ServiceLoader<ModuleDefine> moduleServiceLoader = ServiceLoader.load(ModuleDefine.class);
// 加載ModuleProvider的實現(xiàn)類
ServiceLoader<ModuleProvider> moduleProviderLoader = ServiceLoader.load(ModuleProvider.class);
HashSet<String> moduleSet = new HashSet<>(Arrays.asList(moduleNames));
for (ModuleDefine module : moduleServiceLoader) {
if (moduleSet.contains(module.name())) {
module.prepare(this, applicationConfiguration.getModuleConfiguration(module.name()), moduleProviderLoader);
loadedModules.put(module.name(), module);
moduleSet.remove(module.name());
}
}
// Finish prepare stage
isInPrepareStage = false;
if (moduleSet.size() > 0) {
throw new ModuleNotFoundException(moduleSet.toString() + " missing.");
}
BootstrapFlow bootstrapFlow = new BootstrapFlow(loadedModules);
bootstrapFlow.start(this);
bootstrapFlow.notifyAfterCompleted();
}
三厕宗、 Agent
Agent 作為代理端插件 画舌，協(xié)助 OAP 收集應(yīng)用的日志，作為一個字節(jié)碼插件 skywalking-agent.jar 完成這個工作已慢，上面提到曲聂，當業(yè)務(wù)應(yīng)用端部署時除了這個jar包，還需依賴 agent.config配置和其他插件 jar包佑惠。
public static void premain(String agentArgs, Instrumentation instrumentation) throws PluginException {
final PluginFinder pluginFinder;
//1. 初始化配置文件 agent.config,會在和skywalking-agent.jar同目錄的config下查找
try {
SnifferConfigInitializer.initializeCoreConfig(agentArgs);
} catch (Exception e) {
// try to resolve a new logger, and use the new logger to write the error log here
LogManager.getLogger(SkyWalkingAgent.class)
.error(e, "SkyWalking agent initialized failure. Shutting down.");
return;
} finally {
// refresh logger again after initialization finishes
LOGGER = LogManager.getLogger(SkyWalkingAgent.class);
}
//2. 第一步： 讀取agent.config的plugin.mount參數(shù)朋腋，從plugins,activations兩個目錄下加載插件
// 第二步： 每個插件下面都有一個skywalking-plugin.def文件（SPI模式）齐疙，定義了此插件監(jiān)控的各個點的類
try {
pluginFinder = new PluginFinder(new PluginBootstrap().loadPlugins());
} catch (AgentPackageNotFoundException ape) {
LOGGER.error(ape, "Locate agent.jar failure. Shutting down.");
return;
} catch (Exception e) {
LOGGER.error(e, "SkyWalking agent initialized failure. Shutting down.");
return;
}
//3. 初始化Byte Buddy字節(jié)碼工具，此工具是新一代的字節(jié)碼工具旭咽，性能優(yōu)于ASM贞奋、javasisst
final ByteBuddy byteBuddy = new ByteBuddy().with(TypeValidation.of(Config.Agent.IS_OPEN_DEBUGGING_CLASS));
AgentBuilder agentBuilder = new AgentBuilder.Default(byteBuddy).ignore(
nameStartsWith("net.bytebuddy.")
.or(nameStartsWith("org.slf4j."))
.or(nameStartsWith("org.groovy."))
.or(nameContains("javassist"))
.or(nameContains(".asm."))
.or(nameContains(".reflectasm."))
.or(nameStartsWith("sun.reflect"))
.or(allSkyWalkingAgentExcludeToolkit())
.or(ElementMatchers.isSynthetic()));
JDK9ModuleExporter.EdgeClasses edgeClasses = new JDK9ModuleExporter.EdgeClasses();
try {
agentBuilder = BootstrapInstrumentBoost.inject(pluginFinder, instrumentation, agentBuilder, edgeClasses);
} catch (Exception e) {
LOGGER.error(e, "SkyWalking agent inject bootstrap instrumentation failure. Shutting down.");
return;
}
try {
agentBuilder = JDK9ModuleExporter.openReadEdge(instrumentation, agentBuilder, edgeClasses);
} catch (Exception e) {
LOGGER.error(e, "SkyWalking agent open read edge in JDK 9+ failure. Shutting down.");
return;
}
if (Config.Agent.IS_CACHE_ENHANCED_CLASS) {
try {
agentBuilder = agentBuilder.with(new CacheableTransformerDecorator(Config.Agent.CLASS_CACHE_MODE));
LOGGER.info("SkyWalking agent class cache [{}] activated.", Config.Agent.CLASS_CACHE_MODE);
} catch (Exception e) {
LOGGER.error(e, "SkyWalking agent can't active class cache.");
}
}
// 4. 初始化Agent工具
agentBuilder.type(pluginFinder.buildMatch())
.transform(new Transformer(pluginFinder))
.with(AgentBuilder.RedefinitionStrategy.RETRANSFORMATION)
.with(new RedefinitionListener())
.with(new Listener())
.installOn(instrumentation);
// 5. 啟動所有插件服務(wù)，每個插件服務(wù)必須實現(xiàn)BootService接口類
try {
ServiceManager.INSTANCE.boot();
} catch (Exception e) {
LOGGER.error(e, "Skywalking agent boot failure.");
}
Runtime.getRuntime()
.addShutdownHook(new Thread(ServiceManager.INSTANCE::shutdown, "skywalking service shutdown thread"));
}
上面第5 步中 服務(wù)類穷绵，如果帶@DefaultImplementor注解就是缺省的實現(xiàn)轿塔；如果帶@OverrideImplementor注解，則會覆蓋注解中的指定的某個實現(xiàn)類仲墨，從而產(chǎn)生一個新的實現(xiàn)類
@OverrideImplementor(TraceSegmentServiceClient.class)
public class KafkaTraceSegmentServiceClient implements BootService, IConsumer<TraceSegment>, TracingContextListener, KafkaConnectionStatusListener {
private static final ILog LOGGER = LogManager.getLogger(KafkaTraceSegmentServiceClient.class);
ServiceManager類勾缭，用來管理所有插件
private Map<Class, BootService> loadAllServices() {
Map<Class, BootService> bootedServices = new LinkedHashMap<>();
List<BootService> allServices = new LinkedList<>();
load(allServices);
for (final BootService bootService : allServices) {
Class<? extends BootService> bootServiceClass = bootService.getClass();
boolean isDefaultImplementor = bootServiceClass.isAnnotationPresent(DefaultImplementor.class);
if (isDefaultImplementor) {//有@DefaultImplementor注解
if (!bootedServices.containsKey(bootServiceClass)) {
bootedServices.put(bootServiceClass, bootService);
} else {
//ignore the default service
}
} else {//有@OverrideImplementor注解
OverrideImplementor overrideImplementor = bootServiceClass.getAnnotation(OverrideImplementor.class);
if (overrideImplementor == null) {
if (!bootedServices.containsKey(bootServiceClass)) {
bootedServices.put(bootServiceClass, bootService);
} else {
throw new ServiceConflictException("Duplicate service define for :" + bootServiceClass);
}
}
發(fā)送數(shù)據(jù)
大概分三類發(fā)送數(shù)據(jù)的客戶端：
服務(wù)類客戶端，如ServiceManagementClient
跟蹤類客戶端目养，如TraceSegmentServiceClient
指標類客戶端俩由，如MeterSender。
這三類客戶端除前面講的實現(xiàn)了BootService外混稽，還實現(xiàn)了GRPCChannelListener接口采驻，這個接口大概作用就是創(chuàng)建用于和服務(wù)端通信的通道。大概流程是在調(diào)用ServiceManager.boot()方法時匈勋，會調(diào)用每個服務(wù)的prepare()方法礼旅，收集通道監(jiān)聽器，然后遍歷每個通道的statusChanged方法洽洁，初始化一個XxxServiceStub服務(wù)存根類痘系，此類是由Protobuf序列化而成。
//實現(xiàn)了 GRPCChannelListener 類的prepare()饿自、statusChanged()方法
@DefaultImplementor
public class MeterSender implements BootService, GRPCChannelListener {
private static final ILog LOGGER = LogManager.getLogger(MeterSender.class);
private volatile GRPCChannelStatus status = GRPCChannelStatus.DISCONNECT;
private volatile MeterReportServiceGrpc.MeterReportServiceStub meterReportServiceStub;
@Override
public void prepare() {
ServiceManager.INSTANCE.findService(GRPCChannelManager.class).addChannelListener(this);
}
public void send(Map<MeterId, BaseMeter> meterMap, MeterService meterService) {
if (status == GRPCChannelStatus.CONNECTED) {
StreamObserver<MeterData> reportStreamObserver = null;
final GRPCStreamServiceStatus status = new GRPCStreamServiceStatus(false);
try {
reportStreamObserver = meterReportServiceStub.withDeadlineAfter(
......
}
@Override
public void statusChanged(final GRPCChannelStatus status) {
if (GRPCChannelStatus.CONNECTED.equals(status)) {
Channel channel = ServiceManager.INSTANCE.findService(GRPCChannelManager.class).getChannel();
meterReportServiceStub = MeterReportServiceGrpc.newStub(channel);
} else {
meterReportServiceStub = null;
}
this.status = status;
}
}
Agent Instance
什么是Agent Instance呢汰翠？每通過skywalking-agent.jar啟動一個應(yīng)用，就會在OAP服務(wù)上注冊一個服務(wù)昭雌，而這時就會在Agent端產(chǎn)生一個 Agent實例复唤，它負責(zé)向OAP上報各種信息。ServiceManagementClient類就是做這些工作的烛卧，除了發(fā)送應(yīng)用跟蹤信息外佛纫，還會向OAP發(fā)送心跳等信息。
@DefaultImplementor
public class ServiceManagementClient implements BootService, Runnable, GRPCChannelListener {
private static final ILog LOGGER = LogManager.getLogger(ServiceManagementClient.class);
private static List<KeyStringValuePair> SERVICE_INSTANCE_PROPERTIES;
private volatile GRPCChannelStatus status = GRPCChannelStatus.DISCONNECT;
private volatile ManagementServiceGrpc.ManagementServiceBlockingStub managementServiceBlockingStub;
private volatile ScheduledFuture<?> heartbeatFuture;
private volatile AtomicInteger sendPropertiesCounter = new AtomicInteger(0);
@Override
public void statusChanged(GRPCChannelStatus status) {
if (GRPCChannelStatus.CONNECTED.equals(status)) {
Channel channel = ServiceManager.INSTANCE.findService(GRPCChannelManager.class).getChannel();
managementServiceBlockingStub = ManagementServiceGrpc.newBlockingStub(channel);
} else {
managementServiceBlockingStub = null;
}
this.status = status;
}
@Override
public void prepare() {
ServiceManager.INSTANCE.findService(GRPCChannelManager.class).addChannelListener(this);
SERVICE_INSTANCE_PROPERTIES = new ArrayList<>();
for (String key : Config.Agent.INSTANCE_PROPERTIES.keySet()) {
SERVICE_INSTANCE_PROPERTIES.add(KeyStringValuePair.newBuilder()
.setKey(key)
.setValue(Config.Agent.INSTANCE_PROPERTIES.get(key))
.build());
}
}
@Override
public void boot() {
heartbeatFuture = Executors.newSingleThreadScheduledExecutor(
new DefaultNamedThreadFactory("ServiceManagementClient")
).scheduleAtFixedRate(
new RunnableWithExceptionProtection(
this,
t -> LOGGER.error("unexpected exception.", t)
), 0, Config.Collector.HEARTBEAT_PERIOD,
TimeUnit.SECONDS
);
}
@Override
public void onComplete() {
}
@Override
public void shutdown() {
heartbeatFuture.cancel(true);
}
@Override
public void run() {
LOGGER.debug("ServiceManagementClient running, status:{}.", status);
if (GRPCChannelStatus.CONNECTED.equals(status)) {
try {
if (managementServiceBlockingStub != null) {
if (Math.abs(sendPropertiesCounter.getAndAdd(1)) % Config.Collector.PROPERTIES_REPORT_PERIOD_FACTOR == 0) {
managementServiceBlockingStub
.withDeadlineAfter(GRPC_UPSTREAM_TIMEOUT, TimeUnit.SECONDS)
.reportInstanceProperties(InstanceProperties.newBuilder()
.setService(Config.Agent.SERVICE_NAME)
.setServiceInstance(Config.Agent.INSTANCE_NAME)
.addAllProperties(OSUtil.buildOSInfo(
Config.OsInfo.IPV4_LIST_SIZE))
.addAllProperties(SERVICE_INSTANCE_PROPERTIES)
.build());
} else {
final Commands commands = managementServiceBlockingStub.withDeadlineAfter(
GRPC_UPSTREAM_TIMEOUT, TimeUnit.SECONDS
).keepAlive(InstancePingPkg.newBuilder()
.setService(Config.Agent.SERVICE_NAME)
.setServiceInstance(Config.Agent.INSTANCE_NAME)
.build());
ServiceManager.INSTANCE.findService(CommandService.class).receiveCommand(commands);
}
}
} catch (Throwable t) {
LOGGER.error(t, "ServiceManagementClient execute fail.");
ServiceManager.INSTANCE.findService(GRPCChannelManager.class).reportError(t);
}
}
}
}
四总放、 Plugins
Skywalking中有大量的插件呈宇，正是這些插件幫助Skywalking建立起一個龐大的可觀察森林。每個插件都有兩個必須的類：
- 攔截點類（XxxInstrumentation）局雄，在那些方法上干活甥啄。
- 攔截器類（XxxInterceptor），具體干活的類炬搭。
攔截點
下面以Dubbo插件為例蜈漓，DubboInstrumentation攔截點實現(xiàn)了三個方法：enhanceClass(增強類)穆桂、getConstructorsInterceptPoints(攔截構(gòu)造方法)、getInstanceMethodsInterceptPoints(攔截實例方法)
public class DubboInstrumentation extends ClassInstanceMethodsEnhancePluginDefine {
//被攔截的類融虽，也就是需要增強的類
private static final String ENHANCE_CLASS = "com.alibaba.dubbo.monitor.support.MonitorFilter";
//攔截器類
private static final String INTERCEPT_CLASS = "org.apache.skywalking.apm.plugin.dubbo.DubboInterceptor";
@Override
protected ClassMatch enhanceClass() {
return NameMatch.byName(ENHANCE_CLASS);
}
@Override
public ConstructorInterceptPoint[] getConstructorsInterceptPoints() {
return null;
}
@Override
public InstanceMethodsInterceptPoint[] getInstanceMethodsInterceptPoints() {
return new InstanceMethodsInterceptPoint[] {
new InstanceMethodsInterceptPoint() {
// 獲取匹配到的攔截方法充尉，WitnessClass
@Override
public ElementMatcher<MethodDescription> getMethodsMatcher() {
return named("invoke");
}
// 返回攔截器
@Override
public String getMethodsInterceptor() {
return INTERCEPT_CLASS;
}
// 是否要對原方法參數(shù)做修改
@Override
public boolean isOverrideArgs() {
return false;
}
}
};
}
}
如何解決多版本問題
當應(yīng)用存在多個版本時，Skywalking為應(yīng)用的每個版本都寫一個相對應(yīng)插件版本衣形，例如針對 spring mvc不同版本有以下插件：
spring3.x => mvc-annotation-3.x-plugin
spring4.x => mvc-annotation-4.x-plugin
spring5.x => mvc-annotation-5.x-plugin
那么有個問題來了驼侠，比如我用spring4.x時，這時會把3個插件都加載上谆吴，如何值加載 mvc-annotation-4.x-plugin插件呢倒源？這時用到了一個技術(shù)叫 WitnessClass，原理很簡單句狼，就是在每個插件中定義 WITHNESS_CLASSES變量笋熬，并定義一個能區(qū)分出版本獨特的類。然后在應(yīng)用啟動時腻菇，在加載類集合里是否能找到WITHNESS_CLASSES變量定義的類胳螟，如果找對了，那么也找到了對應(yīng)的版本的插件筹吐。
攔截器
DubboInterceptor用來定義對增強類做什么處理
public class DubboInterceptor implements InstanceMethodsAroundInterceptor {
/**
* <h2>Consumer:</h2> The serialized trace context data will
* inject to the {@link RpcContext#attachments} for transport to provider side.
* <p>
* <h2>Provider:</h2> The serialized trace context data will extract from
* {@link RpcContext#attachments}. current trace segment will ref if the serialize context data is not null.
*/
@Override
public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
MethodInterceptResult result) throws Throwable {
Invoker invoker = (Invoker) allArguments[0];
Invocation invocation = (Invocation) allArguments[1];
RpcContext rpcContext = RpcContext.getContext();
boolean isConsumer = rpcContext.isConsumerSide();
URL requestURL = invoker.getUrl();
AbstractSpan span;
final String host = requestURL.getHost();
final int port = requestURL.getPort();
if (isConsumer) {
final ContextCarrier contextCarrier = new ContextCarrier();
span = ContextManager.createExitSpan(generateOperationName(requestURL, invocation), contextCarrier, host + ":" + port);
//invocation.getAttachments().put("contextData", contextDataStr);
//@see https://github.com/alibaba/dubbo/blob/dubbo-2.5.3/dubbo-rpc/dubbo-rpc-api/src/main/java/com/alibaba/dubbo/rpc/RpcInvocation.java#L154-L161
CarrierItem next = contextCarrier.items();
while (next.hasNext()) {
next = next.next();
rpcContext.getAttachments().put(next.getHeadKey(), next.getHeadValue());
if (invocation.getAttachments().containsKey(next.getHeadKey())) {
invocation.getAttachments().remove(next.getHeadKey());
}
}
} else {
ContextCarrier contextCarrier = new ContextCarrier();
CarrierItem next = contextCarrier.items();
while (next.hasNext()) {
next = next.next();
next.setHeadValue(rpcContext.getAttachment(next.getHeadKey()));
}
span = ContextManager.createEntrySpan(generateOperationName(requestURL, invocation), contextCarrier);
}
Tags.URL.set(span, generateRequestURL(requestURL, invocation));
span.setComponent(ComponentsDefine.DUBBO);
SpanLayer.asRPCFramework(span);
}
@Override
public Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
Object ret) throws Throwable {
Result result = (Result) ret;
if (result != null && result.getException() != null) {
dealException(result.getException());
}
ContextManager.stopSpan();
return ret;
}
@Override
public void handleMethodException(EnhancedInstance objInst, Method method, Object[] allArguments,
Class<?>[] argumentsTypes, Throwable t) {
dealException(t);
}
/**
* Log the throwable, which occurs in Dubbo RPC service.
*/
private void dealException(Throwable throwable) {
AbstractSpan span = ContextManager.activeSpan();
span.log(throwable);
}
/**
* Format operation name. e.g. org.apache.skywalking.apm.plugin.test.Test.test(String)
*
* @return operation name.
*/
private String generateOperationName(URL requestURL, Invocation invocation) {
StringBuilder operationName = new StringBuilder();
String groupStr = requestURL.getParameter(Constants.GROUP_KEY);
groupStr = StringUtil.isEmpty(groupStr) ? "" : groupStr + "/";
operationName.append(groupStr);
operationName.append(requestURL.getPath());
operationName.append("." + invocation.getMethodName() + "(");
for (Class<?> classes : invocation.getParameterTypes()) {
operationName.append(classes.getSimpleName() + ",");
}
if (invocation.getParameterTypes().length > 0) {
operationName.delete(operationName.length() - 1, operationName.length());
}
operationName.append(")");
return operationName.toString();
}
/**
* Format request url. e.g. dubbo://127.0.0.1:20880/org.apache.skywalking.apm.plugin.test.Test.test(String).
*
* @return request url.
*/
private String generateRequestURL(URL url, Invocation invocation) {
StringBuilder requestURL = new StringBuilder();
requestURL.append(url.getProtocol() + "://");
requestURL.append(url.getHost());
requestURL.append(":" + url.getPort() + "/");
requestURL.append(generateOperationName(url, invocation));
return requestURL.toString();
}
}
五糖耸、GraphQL
GraphQL 是一種新的API 查詢語言，由Facebook開源丘薛，對前端提供少許接口嘉竟，就可以查詢整個系統(tǒng)的數(shù)據(jù)，且可以實現(xiàn)按需返回洋侨。
后臺需要先定義一個 schema.graphqls的文件舍扰，下面定義了兩個接口：
- findAuthorById 返回 Author對象，其中這個對象又關(guān)聯(lián)了 Book對象
- saveBook 保存Book接口希坚，它的輸入?yún)?shù)由 input 來定義
#查詢接口
type Query {
findAuthorById(id:Long!): Author
}
# 更新接口
type Mutation {
saveBook(input: BookInput!) : Book!
}
# Author 對象
type Author {
#作者Id
id: Long!
#創(chuàng)建時間
createdTime: String
#名
firstName: String
#姓
lastName: String
#該作者的所有書籍
books: [Book]
}
# 輸入?yún)?shù)
input BookInput {
title: String!
isbn: String!
pageCount: Int
authorId: Long
}
# Book對象
type Book {
id: Long!
title: String!
isbn: String!
pageCount: Int
author: Author
}
對于查詢類接口和 更新類接口繼承的父類是不一樣的边苹，比如查詢是繼承GraphQLQueryResolver，更新是繼承GraphQLMutationResolver
@Component
@AllArgsConstructor
public class Query implements GraphQLQueryResolver {
private AuthorRepo authorRepo;
public Author findAuthorById(Long id) {
return authorRepo.findAuthorById(id);
}
}
@Component
@AllArgsConstructor
public class Mutation implements GraphQLMutationResolver {
private BookRepo bookRepo;
public Book saveBook(BookInput input) {
Book book = new Book();
book.setTitle(input.getTitle());
book.setIsbn(input.getIsbn());
book.setPageCount(input.getPageCount());
book.setAuthorId(input.getAuthorId());
return bookRepo.save(book);
}
}
后臺定義好了GraphQL 接口裁僧，前端請求 http://x.x.x.x/graphql 个束，輸入請求參數(shù)：
{
findAuthorById(id: 3){
id
firstName
lastName
}
}
在Skywalking中，有一個插件： query-graphql-plugin锅知，就相當于一個graphql播急，支撐整個 UI的查詢脓钾，訪問前端 Web時售睹，F(xiàn)12看下發(fā)現(xiàn)調(diào)用的都是 …/graphql 的接口。
六可训、OpenTelemeTry
在了解OpenTelemeTry之前昌妹，先說說 OpenTracing 和 OpenCensus
OpenTracing：是CNCF的第三個項目捶枢，其目的是制定一套標準的分布式追蹤協(xié)議，可謂是Tracing界的slf4j飞崖。
OpenCensus: 除了OpenTracing 鏈路跟蹤外烂叔，還有一類 Metrics監(jiān)控指標也是經(jīng)常用到的，例如cpu固歪、內(nèi)存蒜鸡、硬盤、網(wǎng)絡(luò)請求延遲牢裳、錯誤率逢防、用戶數(shù)、訪問數(shù)蒲讯、訂單數(shù)等各類指標忘朝。沒錯OpenCensus就是將鏈路跟蹤和指標監(jiān)控都囊括了。
所謂分久必合判帮，OpenTelemetry的橫空出世局嘁，結(jié)束了監(jiān)控界的紛爭亂世，并以“可觀察性”全新定義了監(jiān)控技術(shù)晦墙，重塑了監(jiān)控規(guī)范悦昵，實現(xiàn)了Metrics、Tracing晌畅、Logging 的大融合旱捧，儼然成了監(jiān)控界的大佬。
image-20210816162849338.png
Skywalking收集 VM (操作系統(tǒng))指標踩麦，沒有自己實現(xiàn)枚赡，是通過 prometheus 的 node-exporter 完成的，并借助OpenTelemeTry 將Skywalking 和 prometheus 整合到一塊谓谦。
image.png
otel-collector-config.yaml
Receiver做為采集端贫橙，Exporter作為數(shù)據(jù)的輸出端，Opentelemetry-collector充當一個中間媒介將兩者統(tǒng)一起來
receivers:
prometheus:
config:
scrape_configs:
- job_name: 'otel-collector'
scrape_interval: 10s
static_configs:
- targets: [ 'vm-1:9100' ]
- targets: [ 'vm-2:9100' ]
- targets: [ 'vm-3:9100' ]
processors:
batch:
exporters:
opencensus:
endpoint: "oap:11800" # The OAP Server address
insecure: true
# Exports data to the console
logging:
logLevel: debug
service:
pipelines:
metrics:
receivers: [prometheus]
processors: [batch]
exporters: [opencensus,logging]
image-20210817164057977.png
在Skywalking中是通過 proto文件方式來集成opentelemetry的反粥，當然你可以通過 集成opentelemetry sdk來接收node-exporter的數(shù)據(jù)卢肃。Skywalking重寫了 MetricsServiceGrpc.MetricsServiceImplBase的exporer方法，此方法就是專門接收collector發(fā)過來的數(shù)據(jù)才顿，只不過它轉(zhuǎn)了一次轉(zhuǎn)換莫湘，將OpenTelemetry 數(shù)據(jù)格式轉(zhuǎn)換為了Skywalking的meter格式。
@Slf4j
public class OCMetricHandler extends MetricsServiceGrpc.MetricsServiceImplBase implements Handler {
private List<PrometheusMetricConverter> metrics;
@Override public StreamObserver<ExportMetricsServiceRequest> export(
StreamObserver<ExportMetricsServiceResponse> responseObserver) {
return new StreamObserver<ExportMetricsServiceRequest>() {
private Node node;
private Map<String, String> nodeLabels = new HashMap<>();
@Override
public void onNext(ExportMetricsServiceRequest request) {
....
}
@Override public void onError(Throwable throwable) {
}
@Override public void onCompleted() {
responseObserver.onCompleted();
}
};
}
.....
@Override public void active(List<String> enabledRules,
MeterSystem service, GRPCHandlerRegister grpcHandlerRegister) {
List<Rule> rules;
try {
rules = Rules.loadRules("otel-oc-rules", enabledRules);
} catch (ModuleStartException e) {
log.warn("failed to load otel-oc-rules");
return;
}
if (rules.isEmpty()) {
return;
}
this.metrics = rules.stream().map(r ->
new PrometheusMetricConverter(r, service))
.collect(toList());
grpcHandlerRegister.addHandler(this);
}
}
Application
在Skywalking 源碼工程中創(chuàng)建一個模塊apm-webapp（已經(jīng)存在的有問題郑气，我就刪掉了）幅垮，然后把skywalking-ui工程下的dist目錄拷貝到 resources下面，并改名為public尾组，這樣這個工程即可以訪問 UI ,又能集成skywalking-agent.jar測試 忙芒。此工程已經(jīng)上傳到gitee上示弓，請點擊這里下載。
在工程啟動 VM 參數(shù)添加
-javaagent:skywalking-agent\skywalking-agent.jar -Dskywalking.agent.service_name=webapp -Dskywalking.agent.instance_name=webapp -Dskywalking.collector.backend_service=127.0.0.1:11800
訪問 UI
