Ravi Sir's Cards › AWS
Stop double cron runs?
What is a VPC: your own private network inside one AWS Region, example ThreeTierVpc 10.0.0.0/16.
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What this card says
What it is
Use a lock file.
Why it matters
Exit if locked.
flock -n /var/lock/j.lock job
How / example
Kernel frees it.