[性能工具] Locust 应用-单接口压测

之前发了一篇文章[性能测试工具] Locust学习之基础篇，专门介绍Locust。现在专门讲一下我是如何使用Locust做单接口性能测试的。

locustfile_example

#!/usr/bin/env python

# -*- coding: utf-8 -*-

# @Time:2022/11/16 11:27

# @Author:boyizhang

import json

import random


import gevent.monkey

from locust.clients import ResponseContextManager


gevent.monkey.patch_all()


from locust import TaskSet, task, HttpUser



def read_shop_id_from_txt(fileName):

"""

read shop_ids from txt

:return: list

"""

basic_shop_ids = []

with open(fileName, 'r') as f:

for row in f.readlines():

basic_shop_ids.append(int(row))


return basic_shop_ids



class ListingLimitTask(TaskSet):

@task

def get_shop_listing_limit(self):

# random get shop_id

shop_ids = random.sample(self.user.basic_shop_ids, 1)


path = '/your_api_path_xxxxxx'

# 拼装请求

payload = json.dumps({

"shop_ids": shop_ids

})

headers = {}

# 接口调用

with self.client.get(path, headers=headers, data=payload, catch_response=True) as res:

res: ResponseContextManager

# 如果不满足，则标记为failure

# print(f"res:{res.text}")

if res.status_code != 200:

print(f'res:{res.text},body:{payload}')

res.failure(res.text)


def on_start(self):

"""

read basic shop_id group by region

:return:

"""

print('start stress...')



class ListingLimitUser(HttpUser):

host = 'https://xxxxxxxx.xxxx'


tasks = [ListingLimitTask, ]


print('user start...')

# read shop id from file

basic_shop_ids = read_shop_id_from_txt('listing_limit_shop_ids.txt')

print('user start done.')

region = 'ID'



if __name__ == '__main__':

# debug

# run_single_user(ListingLimitUser)

# locust -f listinglimit.py --headless --users 30 --spawn-rate 10 -H https://xxx.xxx -t 300s

pass

• 通过read_shop_id_from_txt()从文件中读取测试数据到缓存中。
• 启动Locust，并开始压测时，根据random.sample(self.user.basic_shop_ids, 1)去随机获取shop_id。
• 拿到测试数据：shop_id之后，拼装请求，并发起接口调用请求。

locust worker 更新实例的脚本

Locust 支持分布式压测。
我们可以通过--master、--worker分启动master实例与worker实例进行分布式压测。
另外我们也可以通过docker来启动分布式压测。
如果不想在机器上安装docker，那就通过shell脚本来启动master与worker实例，来控制worker实例的数量，使用方式如下：

• locust_worker_start.sh
  • sh locust_worker_start.sh [worker实例的启动数量]
• locust_worker_stop.sh
  • sh locust_worker_stop.sh [进程搜索关键字，locust] [worker实例关闭的数量]

#!/bin/bash

# master: locust -f locustfile_example.py --headless --users 30 --spawn-rate 10 -H https://xxx.xxx -t 300s --master --expect-workers 3

# 检查参数个数

if [ $# -ne 1 ]; then

echo "Usage: bash $0 worker_num"

exit 1

fi

num=1

worker_num=$1

#echo "-----" >> pid.log

while(( $num<=$worker_num ))

do

echo "worker - $num is starting"

nohup locust -f locustfile_example.py --worker --master-host=127.0.0.1 >> worker.log 2>&1 &

let "num++"

done

#!/bin/bash


# 检查参数个数

if [ $# -ne 2 ]; then

echo "Usage: bash $0 keyword num_processes"

exit 1

fi


# 获取搜索关键字和要关闭的进程个数

keyword=$1

num_processes=$2

grep_worker_label="grep -v $0 |grep -ie "--worker""


# 搜索进程并获取前n个进程ID

command="ps aux | grep -i "$keyword" | $grep_worker_label | head -n $num_processes | awk '{print \$2}'"

echo run command: $command

pids=$(eval $command)

echo pids: $pids

# 判断是否找到进程

if [ -z "$pids" ]; then

echo "No process found with keyword '$keyword'"

else

# 关闭进程

for pid in $pids; do

kill -9 $pid

done

echo "Selected processes $pids have been closed."

fi

脚本压测流程

通过以上脚本的压测流程大致如下：

• 启动master：locust -f locustfile_example.py --headless --users 30 --spawn-rate 10 -H https://xxx.xxx -t 300s --master --expect-workers 3��
  • 备注：通过w键增加1个用户，通过W键增加10个用户。通过s键减少一个用户，通过S键减少10个用户。
• 启动worker： sh locust_worker_start.sh 3
• 关闭一定数量的worker：sh locust_worker_stop.sh locust 2

locust worker 脚本优化

也可以将locust_worker_start.sh 与 locust_worker_stop.sh合并成一个脚本，使用如下：
sh locust_worker.sh [keyword] [expect_worker_count]

#!/bin/bash


# 检查参数个数

if [ $# -ne 2 ]; then

echo "Usage: bash $0 keyword expect_worker_count"

exit 1

fi


grep_worker_label="grep -v $0 |grep -ie "--worker""

# 获取搜索关键字和要关闭的进程个数

keyword=$1

expect_worker_count=$2


function get_pids_count() {

exist_pids_command="ps aux | grep -ie "$keyword" | $grep_worker_label | grep -v $0 | awk '{print \$2}'"

echo run command: $exist_pids_command

exist_pids=$(eval $exist_pids_command)

exist_pid_list=(${exist_pids// / })

echo "数组的元素为: ${exist_pid_list[*]}"

exist_pids_count=${#exist_pid_list[*]}

return $exist_pids_count

}


function remove_worker_instance() {

# 搜索进程并获取前n个进程ID

remove_worker_num=$1

command="ps aux | grep -i "$keyword" | $grep_worker_label | head -n $remove_worker_num | awk '{print \$2}'"

echo run command: $command

pids=$(eval $command)

echo pids: $pids

# 判断是否找到进程

if [ -z "$pids" ]; then

echo "No process found with keyword '$keyword'"

else

# 关闭进程

for pid in $pids; do

kill -9 $pid

done

echo "Selected processes $pids have been closed."

fi

}

function create_worker_instance() {

worker_num=$1

num=1

while (($num <= $worker_num)); do

echo "worker - $num is starting"

nohup locust -f locustfile_example.py --worker --master-host=127.0.0.1 >>worker.log 2>&1 &

let "num++"

done

}


get_pids_count

exist_pids_count=$?

# master: locust -f locustfile_example.py --headless --users 30 --spawn-rate 10 -H https://xxx.xxx -t 300s --master --expect-workers 3

# 检查参数个数

echo "expect_worker_count: $expect_worker_count, exist_pids_count: $exist_pids_count"


if (($exist_pids_count < $expect_worker_count)); then

echo "add worker instance count"

let worker_num=$expect_worker_count-$exist_pids_count

create_worker_instance $worker_num


elif (($exist_pids_count > $expect_worker_count)); then

echo "remove worker instance count"

let remove_worker_num=$exist_pids_count-$expect_worker_count

remove_worker_instance $remove_worker_num

fi


get_pids_count

exist_pids_count=$?

echo "worker instance count: $exist_pids_count"

脚本压测流程

通过以上脚本的压测流程大致如下：

• 启动master：locust -f locustfile_example.py --headless --users 30 --spawn-rate 10 -H https://xxx.xxx -t 300s --master --expect-workers 3��
  • 备注：通过w键增加1个用户，通过W键增加10个用户。通过s键减少一个用户，通过S键减少10个用户。
• 启动worker或者更新worker实例的数量： sh locust_worker.sh locust 3

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