Curl追踪请求延时问题
背景原因:测试环境发现一个连接内网访问和外网访问延迟差别很大,内网访问很快。外网访问很慢。于是我们用curl来诊断问题所在的区域!
命令如下:
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curl -o /dev/null -s -w %{time_namelookup}---%{time_connect}---%{time_starttransfer}---%{time_total}---%{speed_download} "\n" www.36nu.com |
返回结果:
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0.014---0.015---0.018---0.019---1516256.00 |
-o:把curl 返回的html、js 写到垃圾回收站[ /dev/null]
-s:去掉所有状态
-w:按照后面的格式写出rt
time_namelookup:DNS 解析域名www.36nu.com的时间
time_commect:client和server端建立TCP 连接的时间
time_starttransfer:从client发出请求;到web的server 响应第一个字节的时间
time_total:client发出请求;到web的server发送会所有的相应数据的时间
speed_download:下周速度 单位 byte/s
上面这条命令及返回结果可以这么理解:
0.014: DNS 服务器解析www.36nu.com 的时间单位是s
0.015: client发出请求,到c/s 建立TCP 的时间;里面包括DNS解析的时间
0.018: client发出请求;到s响应发出第一个字节开始的时间;包括前面的2个时间
0.019: client发出请求;到s把响应的数据全部发送给client;并关闭connect的时间
1516256.00 :下载数据的速度
建立TCP连接到server返回client第一个字节的时间:0.018s – 0.015s = 0.003s
server把响应数据发送给client的时间:0.019s – 0.018 = 0.01s
#================================curl 其他参数详解============================
curl的部分时间等变量注释:
url_effective The URL that was fetched last. This is most meaningful if you've told curl to follow location: headers. filename_effective The ultimate filename that curl writes out to. This is only meaningful if curl is told to write to a file with the --remote-name or --output option. It's most useful in combination with the --remote-header-name option. (Added in 7.25.1) http_code http状态码,如200成功,301转向,404未找到,500服务器错误等。(The numerical response code that was found in the last retrieved HTTP(S) or FTP(s) transfer. In 7.18.2 the alias response_code was added to show the same info.) http_connect The numerical code that was found in the last response (from a proxy) to a curl CONNECT request. (Added in 7.12.4) time_total 总时间,按秒计。精确到小数点后三位。 (The total time, in seconds, that the full operation lasted. The time will be displayed with millisecond resolution.) time_namelookup DNS解析时间,从请求开始到DNS解析完毕所用时间。(The time, in seconds, it took from the start until the name resolving was completed.) time_connect 连接时间,从开始到建立TCP连接完成所用时间,包括前边DNS解析时间,如果需要单纯的得到连接时间,用这个time_connect时间减去前边time_namelookup时间。以下同理,不再赘述。(The time, in seconds, it took from the start until the TCP connect to the remote host (or proxy) was completed.) time_appconnect 连接建立完成时间,如SSL/SSH等建立连接或者完成三次握手时间。(The time, in seconds, it took from the start until the SSL/SSH/etc connect/handshake to the remote host was completed. (Added in 7.19.0)) time_pretransfer 从开始到准备传输的时间。(The time, in seconds, it took from the start until the file transfer was just about to begin. This includes all pre-transfer commands and negotiations that are specific to the particular protocol(s) involved.) time_redirect 重定向时间,包括到最后一次传输前的几次重定向的DNS解析,连接,预传输,传输时间。(The time, in seconds, it took for all redirection steps include name lookup, connect, pretransfer and transfer before the final transaction was started. time_redirect shows the complete execution time for multiple redirections. (Added in 7.12.3)) time_starttransfer 开始传输时间。在client发出请求之后,Web 服务器返回数据的第一个字节所用的时间(The time, in seconds, it took from the start until the first byte was just about to be transferred. This includes time_pretransfer and also the time the server needed to calculate the result.) size_download 下载大小。(The total amount of bytes that were downloaded.) size_upload 上传大小。(The total amount of bytes that were uploaded.) size_header 下载的header的大小(The total amount of bytes of the downloaded headers.) size_request 请求的大小。(The total amount of bytes that were sent in the HTTP request.) speed_download 下载速度,单位-字节每秒。(The average download speed that curl measured for the complete download. Bytes per second.) speed_upload 上传速度,单位-字节每秒。(The average upload speed that curl measured for the complete upload. Bytes per second.) content_type 就是content-Type,不用多说了,这是一个访问我博客首页返回的结果示例(text/html; charset=UTF-8);(The Content-Type of the requested document, if there was any.) num_connects Number of new connects made in the recent transfer. (Added in 7.12.3) num_redirects Number of redirects that were followed in the request. (Added in 7.12.3) redirect_url When a HTTP request was made without -L to follow redirects, this variable will show the actual URL a redirect would take you to. (Added in 7.18.2) ftp_entry_path The initial path libcurl ended up in when logging on to the remote FTP server. (Added in 7.15.4) ssl_verify_result ssl认证结果,返回0表示认证成功。( The result of the SSL peer certificate verification that was requested. 0 means the verification was successful. (Added in 7.19.0))
- #curl -o /dev/null -s -w %{http_code}:%{http_connect}:%{content_type}:%{time_namelookup}:%{time_redirect}:%{time_pretransfer}:%{time_connect}:%{time_starttransfer}:%{time_total}:%{speed_download} www.baidu.com
输出变量需要按照%{variable_name}的格式,如果需要输出%,double一下即可,即%%,同时,\n是换行,\r是回车,\t是TAB。
-w 指定格式化文件
-o 请求重定向到,不带此参数则控制台输出返回结果
-s 静默,不显示进度
- #vim curl-time.txt
- \n
- http: %{http_code}\n
- dns: %{time_namelookup}s\n
- redirect: %{time_redirect}s\n
- time_connect: %{time_connect}s\n
- time_appconnect: %{time_appconnect}s\n
- time_pretransfer: %{time_pretransfer}s\n
- time_starttransfer: %{time_starttransfer}s\n
- size_download: %{size_download}bytes\n
- speed_download: %{speed_download}B/s\n
- ----------\n
- time_total: %{time_total}s\n
- \n
- #curl -w "@curl_time.txt" -s -H "Content-Type: application/json" --insecure --header 'Host: passport.500.com' --data '{"platform":"android","userimei":"F5D815EA2BD8DBARD","app_channel":"10000","mbimei":"9DB358AF","version":"3.1.4","username":"hqzx","userpass":"976af4"}' --compressed https://119.147.113.177/user/login
1)以json格式数据
2)以&连接参数数据
- #curl -d "data=7778a8143f111272&score=19&app_key=8d49f16fe034b98b&_test_user=test01" "http://127.0.0.1"
3) 附带文本数据,比如通过"浏览"选择本地的card.txt并上传发送post请求,
其中-F 为带文件的形式发送post请求, blob为文本框中的name元素对应的属性值。<type="text" name="blob">
- #curl -F "blob=@card.txt;type=text/plain" "http://172.16.102.208:8089/wiapi/score?leaderboard_id=7778a8143f111272&score=40&app_key=8d49f16fe034b98b&_test_user=test01"
安卓手机可以通过安装终端模拟器,然后在模拟器按以上方法使用curl调试定位app在移动数据网络环境下哪个环节出现慢的问题。