Server crash on MySQL backup using python

I have a python script that backs up my MySQL database to Amazon S3 buckets every hour. I use the script to simply call mysqldump in order to create the dump and then upload it to the S3 bucket using tinys3, note that I set lock-tables to false so that transactions by other applications are not hindered.

Here is the script for your reference:

import tinys3
import os
from django.core.wsgi import get_wsgi_application
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "my_project.settings")
application = get_wsgi_application()
from django.utils import timezone
import pytz
import datetime
import json


timezone.activate(pytz.timezone("Asia/Kolkata"))
current_datetime = timezone.localtime(
    datetime.datetime.utcnow().replace(tzinfo=pytz.utc)
)
dir_struct = '/'.join(current_datetime.strftime("%Y-%m-%d-%H-%M-%S").split('-'))

endpoint = 's3-us-west-2.amazonaws.com'

params = json.load(open('buckets.json'))
S3_ACCESS_KEY=params['S3_ACCESS_KEY']
S3_SECRET_KEY = params["S3_SECRET_KEY"]
bucket = params['mysql']
db_name = params['db_name']

mysql_command = 'sudo mysqldump --defaults-file=/home/ubuntu/.my.cnf --lock-tables=false %s > /home/ubuntu/%s.sql' %(db_name, db_name)
compress_command = "zip -r /home/ubuntu/%s.sql.zip /home/ubuntu/%s.sql" %(db_name, db_name)
delete_command = "sudo rm -rf /home/ubuntu/%s.sql*" %db_name

os.system(mysql_command)
os.system(compress_command)

backup_file = open('/home/ubuntu/%s.sql.zip' %db_name, 'rb')

conn = tinys3.Connection(S3_ACCESS_KEY, S3_SECRET_KEY, tls=True,endpoint=endpoint)
print conn.upload(
    (dir_struct+'%s.sql.zip' %db_name),
    backup_file,
    bucket,
    public=False
)
print conn.get((dir_struct+'%s.sql.zip' %db_name),bucket)

os.system(delete_command)

The problem is that when I start the cron job to run this script every hour, the server crashes after a few hours (say 5 to 7 hours). I haven't found a considerable reason for this behaviour yet. What is the problem here? Is there a fault in this script or something related to MySQL?

It's easy to imagine what's happening here. Mysqldump is slow. Restoration worse.

It is not intended as a fast or scalable solution for backing up substantial amounts of data. With large data sizes, even if the backup step takes a reasonable time, restoring the data can be very slow because replaying the SQL statements involves disk I/O for insertion, index creation, and so on.

Once you take the backup you appear to zip it, then upload it to amazon s3. It's my guess is that your second backup starts before the first one finishes and it keeps escalating until the server is overwhelmed.

Even if your server doesn't crash, you still should not be using this approach because in a few months time you will be spending thumping amounts for storage.

There is a much much better way. Mysql replication. No cronjobs, almost immidiate recovery if the mast goes down, no bulky data transfers.