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SkyWalking 是一个应用性能监控系统，特别为微服务、云原生和基于容器(Docker, Kubernetes, Mesos)体系结构而设计。除了应用指标监控以外，它还能对分布式调用链路进行追踪。类似功能的组件还有：Zipkin、Pinpoint、CAT等。

上几张图，看看效果，然后再一步一步搭建并使用

1. 概念与架构

SkyWalking是一个开源监控平台，用于从服务和云原生基础设施收集、分析、聚合和可视化数据。SkyWalking提供了一种简单的方法来维护分布式系统的清晰视图，甚至可以跨云查看。它是一种现代APM，专门为云原生、基于容器的分布式系统设计。

SkyWalking从三个维度对应用进行监视：service(服务), service instance(实例), endpoint(端点)

服务和实例就不多说了，端点是服务中的某个路径或者说URI

SkyWalking allows users to understand the topology relationship between Services and Endpoints, to view the metrics of every Service/Service Instance/Endpoint and to set alarm rules.

SkyWalking允许用户了解服务和端点之间的拓扑关系，查看每个服务/服务实例/端点的度量，并设置警报规则。

1.1. 架构

SkyWalking逻辑上分为四个部分：Probes(探针), Platform backend(平台后端), Storage(存储), UI

这个结构就很清晰了，探针就是Agent负责采集数据并上报给服务端，服务端对数据进行处理和存储，UI负责展示

1. 下载与安装

SkyWalking有两种版本，ES版本和非ES版。如果我们决定采用ElasticSearch作为存储，那么就下载es版本。

https://skywalking.apache.org/downloads/

https://archive.apache.org/dist/skywalking/

agent目录将来要拷贝到各服务所在机器上用作探针

bin目录是服务启动脚本

config目录是配置文件

oap-libs目录是oap服务运行所需的jar包

webapp目录是web服务运行所需的jar包

接下来，要选择存储了，支持的存储有：

• H2
• ElasticSearch 6, 7
• MySQL
• TiDB
• InfluxDB

作为监控系统，首先排除H2和MySQL，这里推荐InfluxDB，它本身就是时序数据库，非常适合这种场景

但是InfluxDB我不是很熟悉，所以这里先用ElasticSearch7

https://github.com/apache/skywalking/blob/master/docs/en/setup/backend/backend-storage.md

2.1. 安装ElasticSearch

https://www.elastic.co/guide/en/elasticsearch/reference/7.10/targz.html

# 启动
./bin/elasticsearch -d -p pid
# 停止
pkill -F pid

ElasticSearch7.x需要Java 11以上的版本，但是如果你设置了环境变量JAVA_HOME的话，它会用你自己的Java版本

通常，启动过程中会报以下三个错误：

[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]
[2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
[3]: the default discovery settings are unsuitable for production use; at least one of [discovery.seed_hosts, discovery.seed_providers, cluster.initial_master_nodes] must be configured

解决方法：

在 /etc/security/limits.conf 文件中追加以下内容：

* soft nofile 65536
* hard nofile 65536
* soft nproc  4096
* hard nproc  4096

可通过以下四个命令查看修改结果：

ulimit -Hn
ulimit -Sn
ulimit -Hu
ulimit -Su

修改 /etc/sysctl.conf 文件，追加以下内容：

vm.max_map_count=262144

修改es配置文件 elasticsearch.yml 取消注释，保留一个节点

cluster.initial_master_nodes: ["node-1"]

为了能够ip:port方式访问，还需修改网络配置

network.host: 0.0.0.0

修改完是这样的：

至此，ElasticSearch算是启动成功了

一个节点还不够，这里用三个节点搭建一个集群

192.168.100.14 config/elasticsearch.yml

cluster.name: my-monitor
node.name: node-1
network.host: 192.168.100.14
http.port: 9200
discovery.seed_hosts: ["192.168.100.14:9300", "192.168.100.15:9300", "192.168.100.19:9300"]
cluster.initial_master_nodes: ["node-1"]

192.168.100.15 config/elasticsearch.yml

cluster.name: my-monitor
node.name: node-2
network.host: 192.168.100.15
http.port: 9200
discovery.seed_hosts: ["192.168.100.14:9300", "192.168.100.15:9300", "192.168.100.19:9300"]
cluster.initial_master_nodes: ["node-1"]

192.168.100.19 config/elasticsearch.yml

cluster.name: my-monitor
node.name: node-3
network.host: 192.168.100.19
http.port: 9200
discovery.seed_hosts: ["192.168.100.14:9300", "192.168.100.15:9300", "192.168.100.19:9300"]
cluster.initial_master_nodes: ["node-1"]

同时，建议修改三个节点config/jvm.options

-Xms2g
-Xmx2g

依次启动三个节点

pkill -F pid
./bin/elasticsearch -d -p pid

接下来，修改skywalking下config/application.yml 中配置es地址即可

storage:selector: ${SW_STORAGE:elasticsearch7}elasticsearch7:nameSpace: ${SW_NAMESPACE:""}clusterNodes: ${SW_STORAGE_ES_CLUSTER_NODES:192.168.100.14:9200,192.168.100.15:9200,192.168.100.19:9200}

2.2. 安装Agent

https://github.com/apache/skywalking/blob/v8.2.0/docs/en/setup/service-agent/java-agent/README.md

将agent目录拷贝至各服务所在的机器上

scp -r ./agent chengjs@192.168.100.12:~/

这里，我将它拷贝至各个服务目录下

plugins是探针用到各种插件，SkyWalking插件都是即插即用的，可以把optional-plugins中的插件放到plugins中

修改 agent/config/agent.config 配置文件，也可以通过命令行参数指定

主要是配置服务名称和后端服务地址

agent.service_name=${SW_AGENT_NAME:user-center}
collector.backend_service=${SW_AGENT_COLLECTOR_BACKEND_SERVICES:192.168.100.17:11800}

当然，也可以通过环境变量或系统属性的方式来设置，例如：

export SW_AGENT_COLLECTOR_BACKEND_SERVICES=127.0.0.1:11800

最后，在服务启动的时候用命令行参数 -javaagent 来指定探针

java -javaagent:/path/to/skywalking-agent/skywalking-agent.jar -jar yourApp.jar

例如：

java -javaagent:./agent/skywalking-agent.jar -Dspring.profiles.active=dev -Xms512m -Xmx1024m -jar demo-0.0.1-SNAPSHOT.jar

1. 启动服务

修改 webapp/webapp.yml 文件，更改端口号及后端服务地址

server:port: 9000collector:path: /graphqlribbon:ReadTimeout: 10000# Point to all backend's restHost:restPort, split by ,listOfServers: 127.0.0.1:12800

启动服务

bin/startup.sh

或者分别依次启动

bin/oapService.sh
bin/webappService.sh

查看logs目录下的日志文件，看是否启动成功

浏览器访问 http://127.0.0.1:9000

4. 告警

编辑 alarm-settings.yml 设置告警规则和通知

https://github.com/apache/skywalking/blob/v8.2.0/docs/en/setup/backend/backend-alarm.md

重点说下告警通知

为了使用钉钉机器人通知，接下来，新建一个项目

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.4.0</version><relativePath/> <!-- lookup parent from repository --></parent><groupId>com.wt.monitor</groupId><artifactId>skywalking-alarm</artifactId><version>1.0.0-SNAPSHOT</version><name>skywalking-alarm</name><properties><java.version>1.8</java.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>com.aliyun</groupId><artifactId>alibaba-dingtalk-service-sdk</artifactId><version>1.0.1</version></dependency><dependency><groupId>commons-codec</groupId><artifactId>commons-codec</artifactId><version>1.15</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.2.75</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>

可选依赖(不建议引入)

<dependency<groupId>org.apache.skywalking</groupId><artifactId>server-core</artifactId><version>8.2.0</version>
</dependency>

定义告警消息实体类

package com.wt.monitor.skywalking.alarm.domain;import lombok.Data;import java.io.Serializable;/*** @author ChengJianSheng* @date 2020/12/1*/
@Data
public class AlarmMessageDTO implements Serializable {private int scopeId;private String scope;/*** Target scope entity name*/private String name;private String id0;private String id1;private String ruleName;/*** Alarm text message*/private String alarmMessage;/*** Alarm time measured in milliseconds*/private long startTime;}

发送钉钉机器人消息

package com.wt.monitor.skywalking.alarm.service;import com.dingtalk.api.DefaultDingTalkClient;
import com.dingtalk.api.DingTalkClient;
import com.dingtalk.api.request.OapiRobotSendRequest;
import com.taobao.api.ApiException;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.codec.binary.Base64;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;/*** https://ding-doc.dingtalk.com/doc#/serverapi2/qf2nxq* @author ChengJianSheng* @data 2020/12/1*/
@Slf4j
@Service
public class DingTalkAlarmService {@Value("${dingtalk.webhook}")private String webhook;@Value("${dingtalk.secret}")private String secret;public void sendMessage(String content) {try {Long timestamp = System.currentTimeMillis();String stringToSign = timestamp + "\n" + secret;Mac mac = Mac.getInstance("HmacSHA256");mac.init(new SecretKeySpec(secret.getBytes("UTF-8"), "HmacSHA256"));byte[] signData = mac.doFinal(stringToSign.getBytes("UTF-8"));String sign = URLEncoder.encode(new String(Base64.encodeBase64(signData)),"UTF-8");String serverUrl = webhook + "&timestamp=" + timestamp + "&sign=" + sign;DingTalkClient client = new DefaultDingTalkClient(serverUrl);OapiRobotSendRequest request = new OapiRobotSendRequest();request.setMsgtype("text");OapiRobotSendRequest.Text text = new OapiRobotSendRequest.Text();text.setContent(content);request.setText(text);client.execute(request);} catch (ApiException e) {e.printStackTrace();log.error(e.getMessage(), e);} catch (NoSuchAlgorithmException e) {e.printStackTrace();log.error(e.getMessage(), e);} catch (UnsupportedEncodingException e) {e.printStackTrace();log.error(e.getMessage(), e);} catch (InvalidKeyException e) {e.printStackTrace();log.error(e.getMessage(), e);}}
}

AlarmController.java

package com.wt.monitor.skywalking.alarm.controller;import com.alibaba.fastjson.JSON;
import com.wt.monitor.skywalking.alarm.domain.AlarmMessageDTO;
import com.wt.monitor.skywalking.alarm.service.DingTalkAlarmService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import java.text.MessageFormat;
import java.util.List;/*** @author ChengJianSheng* @date 2020/12/1*/
@Slf4j
@RestController
@RequestMapping("/skywalking")
public class AlarmController {@Autowiredprivate DingTalkAlarmService dingTalkAlarmService;@PostMapping("/alarm")public void alarm(@RequestBody List<AlarmMessageDTO> alarmMessageDTOList) {log.info("收到告警信息: {}", JSON.toJSONString(alarmMessageDTOList));if (null != alarmMessageDTOList) {alarmMessageDTOList.forEach(e->dingTalkAlarmService.sendMessage(MessageFormat.format("-----来自SkyWalking的告警-----\n【名称】: {0}\n【消息】: {1}\n", e.getName(), e.getAlarmMessage())));}}
}