无法创建 PoolableConnectionFactory（通信链接故障） - Jmeter

Question

我正在尝试测试数据库，但它给了我无法创建 PoolableConnectionFactory（通信链接故障）错误。

Response message:java.sql.SQLException: Cannot create PoolableConnectionFactory (Communications link failure)

jdbc连接配置：

database url: 
jdbc:mysql://codebytenepal.com.np:3306/database_cbn

为了测试我是否做错了什么，我在 db4free.net 中创建了测试数据库，它运行良好。

database url in jdbc connection: 
jdbc:mysql://db4free.net:3306/shrestha

这有效，但上述无效。可能是什么原因？

提前致谢

Answer 1

您尝试访问的主机没有打开端口 3306，Nmap 报告证明了这一点

root@af33db8ee27e:/# nmap codebytenepal.com.np

Starting Nmap 7.60 ( https://nmap.org ) at 2020-10-13 15:53 UTC
Nmap scan report for codebytenepal.com.np (192.3.201.45)
Host is up (0.0016s latency).
Not shown: 965 filtered ports
PORT      STATE  SERVICE
21/tcp    open   ftp
22/tcp    closed ssh
25/tcp    open   smtp
26/tcp    open   rsftp
53/tcp    open   domain
80/tcp    open   http
110/tcp   open   pop3
143/tcp   open   imap
443/tcp   open   https
587/tcp   open   submission
993/tcp   open   imaps
995/tcp   open   pop3s
8080/tcp  closed http-proxy
8443/tcp  closed https-alt
8888/tcp  open   sun-answerbook
49152/tcp closed unknown
49153/tcp closed unknown
49154/tcp closed unknown
49156/tcp closed unknown
49157/tcp closed unknown
49159/tcp closed unknown
49160/tcp closed unknown
49165/tcp closed unknown
49175/tcp closed unknown
49400/tcp closed compaqdiag
50000/tcp closed ibm-db2
51103/tcp closed unknown
52822/tcp closed unknown
54045/tcp closed unknown
54328/tcp closed unknown
55056/tcp closed unknown
55600/tcp closed unknown
56737/tcp closed unknown
62078/tcp closed iphone-sync
65129/tcp closed unknown

对于其他主机的 3306 端口是开放的：

root@af33db8ee27e:/# nmap -F db4free.net

Starting Nmap 7.60 ( https://nmap.org ) at 2020-10-13 15:58 UTC
Nmap scan report for db4free.net (85.10.205.173)
Host is up (0.016s latency).
Not shown: 96 filtered ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
443/tcp  open  https
3306/tcp open  mysql

Nmap done: 1 IP address (1 host up) scanned in 16.49 seconds

因此，您绝对无法建立与 codebytenepal.com.np:3306 的连接，因为它不对世界开放。

如果您绝对需要对其进行测试，您需要：

1. Bind the database server to listen on192.3.201.45 地址
2. 在firewall 中打开端口 3306

但请注意，它会在您的部署中打开 big security hole，因此在您完成测试后恢复更改

更多信息：MySQL Database and JMeter - How to Test Your Connection