With such an intimidating name, it is possible to get unnecessarily concerned about SQL server deadlocks, but as this article on Sentry One explains they are part and parcel of running a database.
To help you manage them more efficiently and effectively when they arise, here is a quick look at the best way to monitor your SQL server to detect deadlocks in a jiffy.
If you are totally new to SQL server deadlocks, thankfully they are simple to understand. They arise when multiple processes are competing over the same resources, with each operating with an exclusive lock which should grant them unfettered access.
This can create a Catch 22 situation, which means that neither process can move forwards without its rival being terminated. The designated ‘victim’ process will fail, which may seem problematic but is really just a means of making sure that your server can keep working rather than shuddering to a halt.
Detecting deadlocks manually
Because SQL Server was designed with the knowledge that deadlocks can occur, when they do this will be made obvious via an error raised in the call stack for the process which failed.
This error will provide details of the ID for the specific transaction that bit the dust, along with the recommendation that the process is rerun to make sure it can be completed.
You can obviously monitor each process manually to see if any deadlocks occur, although of course this is not ideal and will consume a lot of time and effort.
Using monitoring tools to deliver efficient deadlock detection
The good news is that you do not need to rely solely on your own wits and experience to keep an eye out for SQL server deadlocks, as with the right monitoring solution you should be able to automate this process and also find a suitable solution with greater ease.
Monitoring software should be able to not only pinpoint which processes are causing deadlocks, but also allow you to see this data expressed in a visual way, rather than just showing you a list of text which can be difficult to decipher, especially if you are in a hurry.
The best solutions will achieve all of this without needing you to carry out any in-depth configuration, you can just expect them to express graphically the issues that are plaguing your server so that you can find the right route to tackling them.
It is not just the deadlocked processes themselves that will be detected in this instance, but also the resources to which they were trying to gain access. This will further aid your troubleshooting efforts, allowing you to make quick work of essential SQL server maintenance.
Now you should know that SQL server deadlocks are not a disaster, but rather something that you should be able to take care of so long as you have the right tools at your disposal. It is also worth mentioning that deadlocks are just one of the many things you should be monitoring in relation to the operation and performance of your database, since it is lots of smaller complaints like this that can pile up and lead to much bigger problems.
Taking the time to track everything from I/O and network traffic to CPU and memory usage will allow you to remain attuned to the SQL server ecosystem for which you are responsible. It can feel like you are fighting lots of fires at once, but the more frequently you monitor and maintain your server the better the results will be in the long term.