“Database Deadlocks” – When Transactions Get Stuck Waiting for Each Other

The Scenario: Waiting Forever – or Crashing Fast!

Imagine this: your application is running smoothly – until suddenly, database transactions (i.e. a group of operations such as insert, update, etc. executed as one) start slowing down dramatically. You dig into the logs and there it is: several transactions are stuck, endlessly waiting. Causing the system to slow down or the application to crash completely.

• What happened? Two or more transactions are waiting for each other to release resources, but neither can proceed, resulting in a complete standstill.
• The diagnosis? A classic database deadlock.

The Quick Fix: Break the Cycle

The quickest way to break the deadlock cycle is to identify and terminate one of the conflicting transactions. Most modern databases include automatic deadlock detection mechanisms that will abort one transaction to allow the others to proceed. However, if the system isn’t resolving the deadlock automatically, you may need to manually stop one of the blocked processes to restore normal operations.

Crisis contained: But how did it happen in the first place?

Database deadlocks are a common issue in systems that handle a large number of concurrent transactions. They often stem from poorly structured transactions that lock resources in an inconsistent order.

The Real Fix: Preventing Future Deadlocks

Avoiding future deadlocks means rethinking how your transactions operate.

• Keep transactions short → Minimizes the chances of deadlocks.
• Lock resources consistently → Ensures that resources are locked in a consistent order.
• Use database monitoring tools → Catches deadlock patterns early and reducing their impact on the system.

How to Make Deadlocks a Non-Issue

If your systems are suffering from recurring deadlocks – or you want to make sure they don’t – let’s talk. I help teams fine-tune transaction logic and implement robust monitoring strategies to keep things running smoothly, even under pressure.

Stay Tuned,
Matthias

This blog post is part of our multi-part series, where we describe common software outages and help you resolve them quickly. You can find all other posts under Foreword: Navigating the Storms of Software Outages.