SkyWalking

简介

    微服务架构下，一个请求会涉及多个服务，一个服务也可能依赖其它服务，这样一个请求下来就构成了一个调用链。如果服务部署成高可用，就会有多个节点。如果其中一个节点出现异常，整个请求就会受到到影响，在这种情况下就需要一个工具来帮助我们分析问题、定位问题和解决问题。<br />        Skywalking 是一个开源的可观察性平台，用于收集、分析、聚合和可视化来自服务和云原生基础设施的数据。Skywalking 提供了基于分布式跟踪的应用程序性能监控系统的解决方案，支持 Java、C#、Node.js、Go、PHP 等。<br />![image.png](https://cdn.nlark.com/yuque/0/2021/png/21583952/1637213838100-bb49656e-35c6-46ad-9b92-a82615c593a3.png#clientId=ua999942d-711e-4&crop=0&crop=0&crop=1&crop=1&from=paste&height=281&id=u6eaef295&margin=%5Bobject%20Object%5D&name=image.png&originHeight=561&originWidth=643&originalType=binary&ratio=1&rotation=0&showTitle=false&size=22082&status=done&style=none&taskId=ua60f5a1c-e916-4536-be32-679e6b89e4d&title=&width=321.5)
    DataKit 只需开启 Skywalking Input，即可采集 Skywalking Agent上报来的链路数据。

前置条件

安装 DataKit

<安装 DataKit>

本文datakit版本1.2.11，skywalking agent版本为v8.6.0。

数据接入

开启 Input

开启 SkyWalking 插件，复制 Sample 文件

cd /usr/local/datakit/conf.d/skywalking
cp skywalking.conf.sample skywalking.conf

修改 skywalking.conf 文件 ```

[[inputs.skywalking]]

skywalking grpc server listening on address

address = “localhost:13800”

customer_tags is a list of keys contains keys set by client code like span.SetTag(key, value)

that want to send to data center. Those keys set by client code will take precedence over

keys in [inputs.skywalking.tags]. DOT(.) IN KEY WILL BE REPLACED BY DASH(_) WHEN SENDING.

customer_tags = [“key1”, “key2”, …]

Keep rare tracing resources list switch.

If some resources are rare enough(not presend in 1 hour), those resource will always send

to data center and do not consider samplers and filters.

keep_rare_resource = false

Ignore tracing resources map like service:[resources…].

The service name is the full service name in current application.

The resource list is regular expressions uses to block resource names.

[inputs.skywalking.close_resource]

# service1 = ["resource1", "resource2", ...]
# service2 = ["resource1", "resource2", ...]
# ...

Sampler config uses to set global sampling strategy.

priority uses to set tracing data propagation level, the valid values are -1, 0, 1

-1: always reject any tracing data send to datakit

0: accept tracing data and calculate with sampling_rate

1: always send to data center and do not consider sampling_rate

sampling_rate used to set global sampling rate

[inputs.skywalking.sampler]

# priority = 0
# sampling_rate = 1.0

[inputs.skywalking.tags]

# key1 = "value1"
# key2 = "value2"
# ...

参数说明

- address：接收 skywalking 链路数据的地址

3. 重启 DataKit

systemctl restart datakit

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## Java 链路数据接入
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### 下载 Skywalking Java Agent

1. 下载
- skywalking-java agent [下载](https://archive.apache.org/dist/skywalking/8.6.0/apache-skywalking-apm-8.6.0.tar.gz)

   **注意**： skywalking agent v8.8.3 目前存在不兼容问题无法使用。目前已支持 v8.5.0 v8.6.0 v8.7.0

2. 解压

tar -zxvf /usr/local/java/apache-skywalking-apm-8.6.0.tar.gz


3. 复制插件

        本示例使用了 Spring Cloud Gateway，由于 Gateway 是基于 Webflux 实现的，必须把 skywalking-agent/optional-plugins/ 目录下的 apm-spring-cloud-gateway-2.1.x-plugin-8.3.0.jar 和 apm-spring-webflux-5.x-plugin-8.3.0.jar 复制到 skywalking-agent/plugins/ 目录下。

cp /usr/local/java/skywalking-agent/optional-plugins/apm-spring-cloud-gateway-2.1.x-plugin-8.6.0.jar /usr/local/java/skywalking-agent/plugins/ cp /usr/local/java/skywalking-agent/optional-plugins/apm-spring-webflux-5.x-plugin-8.6.0.jar /usr/local/java/skywalking-agent/plugins/

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### 启动 Java 应用
本示例部署 3 个微服务，pay、orde 和 gateway。

java -javaagent:/usr/local/java/skywalking-agent/skywalking-agent.jar \ -Dskywalking.agent.service_name=skywalking-pay \ -Dskywalking.collector.backend_service=localhost:13800 \ -jar cloud-service-pay-1.0-SNAPSHOT.jar

```
java -javaagent:/usr/local/java/skywalking-agent/skywalking-agent.jar \
-Dskywalking.agent.service_name=skywalking-order   \
-Dskywalking.collector.backend_service=localhost:13800  \
-jar cloud-service-order-1.0-SNAPSHOT.jar

java -javaagent:/usr/local/java/skywalking-agent/skywalking-agent.jar \
-Dskywalking.agent.service_name=skywalking-gateway   \
-Dskywalking.collector.backend_service=localhost:13800  \
-jar   gateway-1.0-SNAPSHOT.jar

参数说明

Dskywalking.agent.service_name：微服务别名
Dskywalking.collector.backend_service：链路数据上报地址

链路数据
前往[观测云](https://console.guance.com/)，进入应用性能监测。
服务

拓扑图

1636941909(1).png

火焰图

观测云最佳实践

SkyWalking 链路数据接入最佳实践