如何计算数据库连接数？

Question

I have database connection number increased this morning, which never happen before. as shown below :

and I don't know why. because there's no user accessing this database. just cronjob which runs since last month and no changes.

so I was wondering, how this database connection number is calculated?

does each SELECT , UPDATE and INSERT count as 1.

or each $conn = new mysqli($servername, $username, $password); count as 1?

Answer 1

Amazon RDS Db connections count is persistent connection made by connecting library. so

$conn = new mysqli($servername, $username, $password); will be counted as 1 single connections.

Reason behind increased connections may be bug in your script or library file. After every successfully select/insert/update/delete actions or performing entire function (at end of cron in your case) you have to close the mysqli connection . RDS will not automatically close your connection and hence when your cron runs next time a new connection will be established and counts goes on increasing.