Skywalking
一、SkyWalking是什么
SkyWalking是分布式系统的应用程序性能监视工具，专为微服务、云原生架构和基于容器（Docker、K8S、Mesos）架构而设计；
SkyWalking是观察性分析平台和应用性能管理系统。提供分布式追踪、服务网格遥测分析、度量聚合和可视化一体化解决方案；
二、Skywalking架构
整个架构，分成上、下、左、右四部分：
上部分 Agent ：负责从应用中，收集链路信息，发送给 SkyWalking OAP 服务器。目前支持 SkyWalking、Zikpin、Jaeger 等提供的 Tracing 数据信息。而我们目前采用的是，SkyWalking Agent 收集 SkyWalking Tracing 数据，传递给服务器。
下部分 SkyWalking OAP ：负责接收 Agent 发送的 Tracing 数据信息，然后进行分析(Analysis Core) ，存储到外部存储器( Storage )，最终提供查询( Query )功能。
右部分 Storage ：Tracing 数据存储。目前支持 ES、MySQL、Sharding Sphere、TiDB、H2 多种存储器。而我们目前采用的是 ES ，主要考虑是 SkyWalking 开发团队自己的生产环境采用 ES 为主。
左部分 SkyWalking UI ：负责提供控台，查看链路等等
三、Skywalking部署
3.1、Skywalking单机环境
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3.2、ElasticSearch搭建
1.上传下载的压缩包到服务器并解压
tar -zxvf elasticsearch-7.4.2-linux-x86_64.tar.gz //解压压缩包
cd elasticsearch-7.4.2 //进入目录
mkdir data //创建data文件夹，保存数据
2.修改Elasticsearch配置：config/elasticsearch.yml
cluster.name: apm-application
node.name: node-1
path.data: /opt/elasticsearch-7.4.2/data
path.logs: /opt/elasticsearch-7.4.2/logs
# ES监听的ip地址
network.host: 0.0.0.0
cluster.initial_master_nodes: ["node-1"]
# 需要开启跨域才能给elasticsearch-head，kibana等连接
http.cors.enabled: true
http.cors.allow-origin: "*"
http.cors.allow-headers: Authorization,X-Requested-With,Content-Length,Content-Type
3.创建Elasticsearch启动用户
groupadd elsearch
useradd elsearch -g elsearch
chown -R elsearch:elsearch elasticsearch-7.4.2
4.修改系统参数，启动elasticsearch
# vi /etc/sysctl.conf
vm.max_map_count=262144
# sysctl -p
cd elasticsearch-7.4.2
su elsearch
./bin/elasticsearch -d
5.前端访问 IP:9200 查看是否启动
3.3、下载 SkyWalking 软件包
1.下载SkyWalking官方包
我们选择apache-skywalking-apm-es7-8.0.0.tar.gz版本想使用 Elasticsearch 7.X 版本作为存储
2.上传下载的压缩包到linux服务器，解压文件
tar -zxvf apache-skywalking-apm-es7-8.0.0.tar.gz
cd apache-skywalking-apm-bin-es7/
3.4、SkyWalking OAP 搭建
1.修改 OAP 配置文件 config/application.yml
storage:
selector: ${SW_STORAGE:elasticsearch7}
elasticsearch:
nameSpace: ${SW_NAMESPACE:""}
clusterNodes: ${SW_STORAGE_ES_CLUSTER_NODES:localhost:9200}
protocol: ${SW_STORAGE_ES_HTTP_PROTOCOL:"http"}
trustStorePath: ${SW_STORAGE_ES_SSL_JKS_PATH:""}
trustStorePass: ${SW_STORAGE_ES_SSL_JKS_PASS:""}
user: ${SW_ES_USER:""}
password: ${SW_ES_PASSWORD:""}
secretsManagementFile: ${SW_ES_SECRETS_MANAGEMENT_FILE:""} # Secrets management file in the properties format includes the username, password, which are manag
ed by 3rd party tool.
dayStep: ${SW_STORAGE_DAY_STEP:1} # Represent the number of days in the one minute/hour/day index.
indexShardsNumber: ${SW_STORAGE_ES_INDEX_SHARDS_NUMBER:1} # The index shards number is for store metrics data rather than basic segment record
superDatasetIndexShardsFactor: ${SW_STORAGE_ES_SUPER_DATASET_INDEX_SHARDS_FACTOR:5} # Super data set has been defined in the codes, such as trace segments. Th
is factor provides more shards for the super data set, shards number = indexShardsNumber * superDatasetIndexShardsFactor. Also, this factor effects Zipkin and Jae
ger traces.
indexReplicasNumber: ${SW_STORAGE_ES_INDEX_REPLICAS_NUMBER:0}
# Batch process setting, refer to https://www.elastic.co/guide/en/elasticsearch/client/java-api/5.5/java-docs-bulk-processor.html
bulkActions: ${SW_STORAGE_ES_BULK_ACTIONS:1000} # Execute the bulk every 1000 requests
flushInterval: ${SW_STORAGE_ES_FLUSH_INTERVAL:10} # flush the bulk every 10 seconds whatever the number of requests
concurrentRequests: ${SW_STORAGE_ES_CONCURRENT_REQUESTS:2} # the number of concurrent requests
resultWindowMaxSize: ${SW_STORAGE_ES_QUERY_MAX_WINDOW_SIZE:10000}
metadataQueryMaxSize: ${SW_STORAGE_ES_QUERY_MAX_SIZE:5000}
segmentQueryMaxSize: ${SW_STORAGE_ES_QUERY_SEGMENT_SIZE:200}
profileTaskQueryMaxSize: ${SW_STORAGE_ES_QUERY_PROFILE_TASK_SIZE:200}
advanced: ${SW_STORAGE_ES_ADVANCED:""}
elasticsearch7:
nameSpace: ${SW_NAMESPACE:""}
clusterNodes: ${SW_STORAGE_ES_CLUSTER_NODES:192.168.20.200:9200}
protocol: ${SW_STORAGE_ES_HTTP_PROTOCOL:"http"}
trustStorePath: ${SW_STORAGE_ES_SSL_JKS_PATH:""}
trustStorePass: ${SW_STORAGE_ES_SSL_JKS_PASS:""}
dayStep: ${SW_STORAGE_DAY_STEP:1} # Represent the number of days in the one minute/hour/day index.
user: ${SW_ES_USER:""}
password: ${SW_ES_PASSWORD:""}
secretsManagementFile: ${SW_ES_SECRETS_MANAGEMENT_FILE:""} # Secrets management file in the properties format includes the username, password, which are manag
ed by 3rd party tool.
indexShardsNumber: ${SW_STORAGE_ES_INDEX_SHARDS_NUMBER:1} # The index shards number is for store metrics data rather than basic segment record
superDatasetIndexShardsFactor: ${SW_STORAGE_ES_SUPER_DATASET_INDEX_SHARDS_FACTOR:5} # Super data set has been defined in the codes, such as trace segments. Th
is factor provides more shards for the super data set, shards number = indexShardsNumber * superDatasetIndexShardsFactor. Also, this factor effects Zipkin and Jae
ger traces.
indexReplicasNumber: ${SW_STORAGE_ES_INDEX_REPLICAS_NUMBER:0}
# Batch process setting, refer to https://www.elastic.co/guide/en/elasticsearch/client/java-api/5.5/java-docs-bulk-processor.html
bulkActions: ${SW_STORAGE_ES_BULK_ACTIONS:1000} # Execute the bulk every 1000 requests
flushInterval: ${SW_STORAGE_ES_FLUSH_INTERVAL:10} # flush the bulk every 10 seconds whatever the number of requests
concurrentRequests: ${SW_STORAGE_ES_CONCURRENT_REQUESTS:2} # the number of concurrent requests
resultWindowMaxSize: ${SW_STORAGE_ES_QUERY_MAX_WINDOW_SIZE:10000}
metadataQueryMaxSize: ${SW_STORAGE_ES_QUERY_MAX_SIZE:5000}
segmentQueryMaxSize: ${SW_STORAGE_ES_QUERY_SEGMENT_SIZE:200}
profileTaskQueryMaxSize: ${SW_STORAGE_ES_QUERY_PROFILE_TASK_SIZE:200}
advanced: ${SW_STORAGE_ES_ADVANCED:""}
2.启动OAP
$ bin/oapService.sh
SkyWalking OAP started successfully!
3.4 SkyWalking UI 搭建
1.由于SkyWalking UI的默认地址是8080，与很多中间件有冲突，可以修改一下
#修改webapp/webapp.yml
server:
port: 18080
2.启动 SkyWalking UI 服务
$ bin/webappService.sh
SkyWalking Web Application started successfully!
3.5 SkyWalking Agent
1.修改探针默认配置 agent/config/agent.config
collector.backend_service=${SW_AGENT_COLLECTOR_BACKEND_SERVICES:192.168.20.200:11800}
agent.sample_n_per_3_secs=${SW_AGENT_SAMPLE:1}
采样率修改
agent.sample_n_per_3_secs配置说明：
在访问量较少时，链路全量收集不会对系统带来太大负担，能够完整的观测到系统的运行状况。但是在访问量较大时，全量的链路收集，对链路收集的客户端（agent探针）、服务端（SkyWalking OAP）、存储器（例如说 Elastcsearch）都会带来较大的性能开销，甚至会影响应用的正常运行。在访问量级较大的情况下，往往会选择抽样采样，只收集部分链路信息。SkyWalking Agent 在 agent/config/agent.config 配置文件中，定义了 agent.sample_n_per_3_secs 配置项，设置每 3 秒可收集的链路数据的数量。
2.放置探针
- 我们需要将 agent 目录，拷贝到 Java 应用所在的服务器上。这样，Java 应用才可以配置使用该 SkyWalking Agent。通过设置启动参数的方式检测系统，没有代码侵入。
#在服务的启动命令中添加参数javaagent、Dskywalking.agent.service_name
nohup java -javaagent:agent/skywalking-agent.jar -Dskywalking.agent.service_name=a -jar a.jar > a.log
- Idea 配置，如果我们是本地启动的项目，开发工具使用的IDEA，我们只需要在如下图所示地方配置启动附加信息即可
# javaagent配置的是agent对应的jar位置。
# Dskywalking.agent.service_name配置建议使用服务的spring.application.name方便区分。
-javaagent:D:\Develop\apache-skywalking-apm-bin-es7\agent\skywalking-agent.jar
-Dskywalking.agent.service_name=leimingtech-admin-api
