Shell中Sampler有什么用

这篇文章主要介绍Shell中Sampler有什么用，文中介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们一定要看完！

Sampler是一个用于shell命令执行，可视化和告警的工具。其配置使用的是一个简单的YAML文件。

为什么我需要它？

你可以直接从终端对任意动态进程进行采样 – 观察数据库中的更改，监控MQ动态消息（in-flight messages），触发部署脚本并在完成后获取通知。

如果有一种方法可以使用shell命令获取指标（metric），那么可以使用Sampler立即对其进行可视化。

安装

macOS

brew cask install sampler

或

sudo curl -Lo /usr/local/bin/sampler https://github.com/sqshq/sampler/releases/download/v1.0.3/sampler-1.0.3-darwin-amd64  sudo chmod +x /usr/local/bin/sampler

Linux

sudo wget https://github.com/sqshq/sampler/releases/download/v1.0.3/sampler-1.0.3-linux-amd64 -O /usr/local/bin/sampler  sudo chmod +x /usr/local/bin/sampler

注意：需要为Sampler安装libasound2-dev系统库用以播放触发器声音。通常库已安装在相应位置，但如果没有 – 你可以使用你习惯的包管理器进行安装，例如apt install libasound2-dev

Windows（实验）

建议在高级控制台模拟器下使用，如Cmder

Download .exe

使用

指定shell命令，Sampler会相应的速率执行这些命令。输出用于可视化。

使用Sampler基本上的三步过程：

在YAML配置文件中定义shell命令

运行sampler -c config.yml

在UI上调整组件大小和位置

市面早已有许多监控系统

Sampler绝不是监控系统的替代品，而是易于设置的开发工具。

如果spinning up和使用Grafana配置Prometheus是完全多余的任务，那么Sampler可能是正确的解决方案。没有服务器，没有数据库，不需要部署 – 你指定了shell命令，它就可以工作了。

我监控的每台服务器上都需要安装吗？

不，你可以在本地运行Sampler，但仍然可以从多台远程计算机上收集遥测数据。任何可视化都可能具有init命令，你可以在其中ssh到远程服务器。请参阅SSH example

组件

以下是每种组件类型的配置示例列表，其中包含与macOS兼容的采样脚本。

Runchart

runcharts:    - title: Search engine response time      rate-ms: 500        # sampling rate, default = 1000      scale: 2            # number of digits after sample decimal point, default = 1      legend:        enabled: true     # enables item labels, default = true        details: false    # enables item statistics: cur/min/max/dlt values, default = true      items:        - label: GOOGLE          sample: curl -o /dev/null -s -w '%{time_total}'  https://www.google.com          color: 178      # 8-bit color number, default one is chosen from a pre-defined palette        - label: YAHOO          sample: curl -o /dev/null -s -w '%{time_total}'  https://search.yahoo.com        - label: BING          sample: curl -o /dev/null -s -w '%{time_total}'  https://www.bing.com

Sparkline

sparklines:    - title: CPU usage      rate-ms: 200      scale: 0      sample: ps -A -o %cpu | awk '{s+=$1} END {print s}'    - title: Free memory pages      rate-ms: 200      scale: 0      sample: memory_pressure | grep 'Pages free' | awk '{print $3}'

Barchart

barcharts:    - title: Local network activity      rate-ms: 500        # sampling rate, default = 1000      scale: 0            # number of digits after sample decimal point, default = 1      items:        - label: UDP bytes in          sample: nettop -J bytes_in -l 1 -m udp | awk '{sum += $4} END {print sum}'        - label: UDP bytes out          sample: nettop -J bytes_out -l 1 -m udp | awk '{sum += $4} END {print sum}'        - label: TCP bytes in          sample: nettop -J bytes_in -l 1 -m tcp | awk '{sum += $4} END {print sum}'        - label: TCP bytes out          sample: nettop -J bytes_out -l 1 -m tcp | awk '{sum += $4} END {print sum}'

Gauge

gauges:    - title: Minute progress      rate-ms: 500        # sampling rate, default = 1000      scale: 2            # number of digits after sample decimal point, default = 1      percent-only: false # toggle display of the current value, default = false      color: 178          # 8-bit color number, default one is chosen from a pre-defined palette      cur:        sample: date +%S  # sample script for current value      max:        sample: echo 60   # sample script for max value      min:        sample: echo 0    # sample script for min value    - title: Year progress      cur:        sample: date +%j      max:        sample: echo 365      min:        sample: echo 0

Textbox

textboxes:    - title: Local weather      rate-ms: 10000      # sampling rate, default = 1000      sample: curl wttr.in?0ATQF      border: false       # border around the item, default = true      color: 178          # 8-bit color number, default is white    - title: Docker containers stats      rate-ms: 500      sample: docker stats --no-stream --format "table {{.Name}}\t{{.CPUPerc}}\t{{.MemUsage}}\t{{.PIDs}}"

Asciibox

asciiboxes:    - title: UTC time      rate-ms: 500        # sampling rate, default = 1000      font: 3d            # font type, default = 2d     border: false       # border around the item, default = true        color: 43           # 8-bit color number, default is white      sample: env TZ=UTC date +%r

额外功能

Triggers

触发器允许执行条件操作，如视觉/声音告警或任意shell命令。以下示例说明了此概念。

Clock gauge，从开始的每分钟显示时间进度和当前时间

gauges:    - title: MINUTE PROGRESS      position: [[0, 18], [80, 0]]        cur:        sample: date +%S      max:        sample: echo 60      min:        sample: echo 0      triggers:        - title: CLOCK BELL EVERY MINUTE          condition: '[ $label == "cur" ] && [ $cur -eq 0 ] && echo 1 || echo 0'  # expects "1" as TRUE indicator          actions:            terminal-bell: true  # standard terminal bell, default = false            sound: true    # NASA quindar tone, default = false            visual: false  # notification with current value on top of the component area, default = false            script: say -v samantha `date +%I:%M%p`  # an arbitrary script, which can use $cur, $prev and $label variables

搜索引擎延迟图表，在延迟超过阈值时向用户发出告警

runcharts:    - title: SEARCH ENGINE RESPONSE TIME (sec)      rate-ms: 200      items:        - label: GOOGLE          sample: curl -o /dev/null -s -w '%{time_total}'  https://www.google.com        - label: YAHOO          sample: curl -o /dev/null -s -w '%{time_total}'  https://search.yahoo.com         triggers:        - title: Latency threshold exceeded          condition: echo "$prev < 0.3 && $cur > 0.3" |bc -l  # expects "1" as TRUE indicator          actions:            terminal-bell: true  # standard terminal bell, default = false            sound: true   # NASA quindar tone, default = false            visual: true  # visual notification on top of the component area, default = false            script: 'say alert: ${label} latency exceeded ${cur} second' # an arbitrary script, which can use $cur, $prev and $label variables

交互式 shell 支持

除了sample命令之外，还可以指定init命令（在采样前仅执行一次）和transform命令（后处理采样命令输出）。这包括交互式shell用例，例如仅建立与数据库的连接一次，然后在交互式shell会话中执行轮询。

Basic mode

textboxes:    - title: MongoDB polling     rate-ms: 500      init: mongo --quiet --host=localhost test # executes only once to start the interactive session      sample: Date.now();                       # executes with a required rate, in scope of the interactive session      transform: echo result = $sample          # executes in scope of local session, $sample variable is available for transformation

PTY mode

在某些情况下，交互式shell将无法工作，因为它的stdin不是终端。这种情况下我们可以使用PTY模式：

textboxes:    - title: Neo4j polling      pty: true  # enables pseudo-terminal mode, default = false      init: cypher-shell -u neo4j -p pwd --format plain      sample: RETURN rand();      transform: echo "$sample" | tail -n 1    - title: Top on a remote server      pty: true  # enables pseudo-terminal mode, default = false      init: ssh -i ~/user.pem ec2-user@1.2.3.4      sample: top

init 命令逐步执行

在开始采样之前，还可以逐个执行多个init命令。

textboxes:    - title: Java application uptime      multistep-init:        - java -jar jmxterm-1.0.0-uber.jar        - open host:port # or local PID        - bean java.lang:type=Runtime      sample: get Uptime

变量

如果配置文件包含重复的模式，则可以将它们提取到变量部分。此外，还可以在启动时使用-v/–variable标志指定变量，并且任意的系统环境变量也可以在脚本中使用。

variables:      mongoconnection: mongo --quiet --host=localhost test  barcharts:    - title: MongoDB documents by status      items:        - label: IN_PROGRESS          init: $mongoconnection          sample: db.getCollection('events').find({status:'IN_PROGRESS'}).count()        - label: SUCCESS          init: $mongoconnection          sample: db.getCollection('events').find({status:'SUCCESS'}).count()        - label: FAIL          init: $mongoconnection          sample: db.getCollection('events').find({status:'FAIL'}).count()

颜色主题

theme: light # default = dark  sparklines:    - title: CPU usage      sample: ps -A -o %cpu | awk '{s+=$1} END {print s}'

真实场景

数据库

以下是不同的数据库连接示例。建议使用交互式shell（init脚本）仅建立一次连接，然后在采样期间重用即可。

MySQL

# prerequisite: installed mysql shell  variables:    mysql_connection: mysql -u root -s --database mysql --skip-column-names  sparklines:      - title: MySQL (random number example)      pty: true      init: $mysql_connection      sample: select rand();

PostgreSQL

# prerequisite: installed psql shell  variables:    PGPASSWORD: pwd    postgres_connection: psql -h localhost -U postgres --no-align --tuples-only  sparklines:    - title: PostgreSQL (random number example)      init: $postgres_connection      sample: select random();

MongoDB

# prerequisite: installed mongo shell  variables:    mongo_connection: mongo --quiet --host=localhost test  sparklines:    - title: MongoDB (random number example)      init: $mongo_connection      sample: Math.random();

Neo4j

# prerequisite: installed cypher shell  variables:    neo4j_connection: cypher-shell -u neo4j -p pwd --format plain  sparklines:    - title: Neo4j (random number example)      pty: true      init: $neo4j_connection      sample: RETURN rand();      transform: echo "$sample" | tail -n 1

Kafka

检查kafka lag值，计算每个队列lag值的和，高于阈值报警，多consumergroup，多topic。

variables:    kafka_connection: $KAFKA_HOME/bin/kafka-consumer-groups --bootstrap-server localhost:9092  runcharts:    - title: Kafka lag per consumer group      rate-ms: 5000      scale: 0      items:        - label: A->B          sample: $kafka_connection --group group_a --describe | awk 'NR>1 {sum += $5} END {print sum}'        - label: B->C          sample: $kafka_connection --group group_b --describe | awk 'NR>1 {sum += $5} END {print sum}'        - label: C->D          sample: $kafka_connection --group group_c --describe | awk 'NR>1 {sum += $5} END {print sum}'

Docker

Docker容器统计信息（CPU，MEM，O/I）

textboxes:    - title: Docker containers stats      sample: docker stats --no-stream --format "table {{.Name}}\t{{.CPUPerc}}\t{{.MemPerc}}\t{{.MemUsage}}\t{{.NetIO}}\t{{.BlockIO}}\t{{.PIDs}}"

SSH

远程服务器上的TOP命令

variables:    sshconnection: ssh -i ~/my-key-pair.pem ec2-user@1.2.3.4  textboxes:    - title: SSH      pty: true      init: $sshconnection      sample: top

JMX

Java应用程序的正常运行示例

# prerequisite: download [jmxterm jar file](https://docs.cyclopsgroup.org/jmxterm)  textboxes:    - title: Java application uptime      multistep-init:        - java -jar jmxterm-1.0.0-uber.jar        - open host:port # or local PID        - bean java.lang:type=Runtime      sample: get Uptime      transform: echo $sample | tr -dc '0-9' | awk '{printf "%.1f min", $1/1000/60}'

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