Django mysql too many connections

Question

I use Django with mysql, and having this problem of too many connections.

I run python script from command line, but integrated with Django model to check the data from database. The script runs every 30 seconds, and I use thread to control that. My_function is the function that will check db status.

while True: 
    now = time.time() 
    if now < next: 
        time.sleep(next - now) 
        t = Thread(target=my_function,)
        t.start()# start a thread

    next += interval

The problem is when I monitor mysql server. There are about 10 connections all the time, and all of them are sleeping. I just don't understand why. There are 2 active python threads running constantly, and all the other threads are terminated when they finish. How come the mysql connection are like 10? Anyone can help me? Much appreciate!

Update 1: Now put the screenshot of mysql processlist. The connections are all in sleep mode and does nothing, and the thread that creates the connection already terminates. That's really strange.

+------+------+-----------------+----------+---------+-------+-------+------------------+
| Id   | User | Host            | db       | Command | Time  | State | Info             |
+------+------+-----------------+----------+---------+-------+-------+------------------+
|  411 | root | localhost:47347 | NULL     | Sleep   |     2 |       | NULL             |
|  412 | root | localhost:47350 | NULL     | Sleep   |     3 |       | NULL             |
|  479 | root | localhost       | NULL     | Sleep   | 27164 |       | NULL             |
|  918 | root | localhost       | EZ_Green | Sleep   | 14006 |       | NULL             |
|  953 | root | localhost       | EZ_Green | Sleep   | 12956 |       | NULL             |
|  989 | root | localhost       | EZ_Green | Sleep   | 11874 |       | NULL             |
| 1025 | root | localhost       | EZ_Green | Sleep   | 10796 |       | NULL             |
| 1061 | root | localhost       | EZ_Green | Sleep   |  9716 |       | NULL             |
| 1097 | root | localhost       | EZ_Green | Sleep   |  8636 |       | NULL             |
| 1132 | root | localhost       | EZ_Green | Sleep   |  7586 |       | NULL             |
| 1168 | root | localhost       | EZ_Green | Sleep   |  6506 |       | NULL             |
| 1204 | root | localhost       | EZ_Green | Sleep   |  5426 |       | NULL             |
| 1240 | root | localhost       | EZ_Green | Sleep   |  4346 |       | NULL             |
| 1276 | root | localhost       | EZ_Green | Sleep   |  3266 |       | NULL             |
| 1312 | root | localhost       | EZ_Green | Sleep   |  2186 |       | NULL             |
| 1348 | root | localhost       | EZ_Green | Sleep   |  1106 |       | NULL             |
| 1384 | root | localhost       | EZ_Green | Sleep   |    26 |       | NULL             |
| 1385 | root | localhost       | NULL     | Query   |     0 | NULL  | show processlist |
+------+------+-----------------+----------+---------+-------+-------+------------------+

Answer 1

As dusty said,

Every thread that uses Django ORM creates a new database connection. And Django will not manage the connection automatically that created by your own thread. So you should manage it.

You can simple do this before each thread exit:

from django.db import connection

# your work thread method 

def my_function():
    # do something...
    # close the db connection explicitly

    connection.close()

Answer 2

Please, see this question

Every thread that uses Django ORM creates a new database connection.