Databases power all modern applications, from banking and ATM software to space shuttle systems and your Angry Birds game. Wherever you go, you will find databases.
The most common databases used today are relational or SQL databases, where data is stored in interconnected tables. In turn, you can query those tables using a query language that resembles plain English, Standard Query Language (SQL). To get the most value of the SQL databases you use as a developer, system administrator, or database administrator, it’s vital that you have visibility into what’s going on. That way you can take a deep dive under the hood and routinely check and monitor the database activity.
What Is an SQL Server Activity Monitor?
Sometimes databases don’t perform optimally in a standard, out-of-the-box configuration. If you have lots of tables and millions of rows, some queries might become slow, the database may be unresponsive, new rows might not be added, and so forth. To routinely monitor your database, analyze bottlenecks, and receive alerts about anomalies, you need SQL Server Activity Monitor. This tool is used across the board, from startups to Fortune 500 companies, by back-end developers and software architects to database administrators. They use it to monitor databases that reside both on premises and in the cloud.
When a problem occurs, it’s vital that you understand in real time what’s causing it and why. For example, if your database suddenly becomes unresponsive, you’ll need to know what happened. Is the machine that the database is running on out of memory? Perhaps the CPU load is too high. Maybe disk usage is at 100 percent. Since on-premises databases are usually hosted on non-isolated virtual machines, other applications and operating systems running on the same hypervisor can cause service disruptions and outages. Even if you use an automatically scaled cloud database, parameters such as the network I/O rate and RAM that are not easily scalable in the cloud can cause a database outage.
One of the classic use cases of an SQL monitor is query optimization. If your application is unresponsive or slow, a slow query operation might be the reason. There’s no fixed number that defines a slow query in terms of milliseconds because it can vary depending on the complexity of the query, the size of the database, and the resources available on the server. However, as a general guideline, a query that takes longer than 100 milliseconds to execute is usually considered slow. A query that takes more than 1 second to execute is usually considered very slow.
Using an SQL Server Activity Monitor to Optimize Queries
An SQL monitor can help you identify slow queries and provide suggestions for optimizing them. For example, it can tell you that you lack indexes for the relevant fields you’re looking for in the query and suggest that you add more. Or it can identify that you lack a primary key in an important table and suggest that you add one. Furthermore, advanced SQL monitors can identify overlapping and redundant indexes that slow the query. If you do have redundant indexes, you can solve two problems at once, both the slow query and the redundant database that requires additional disk storage. Removing the redundant indexes will improve query time and free up disk space for future usage.
Last but not least, a step-by-step analysis of a query can list time-consuming steps that you don’t need and that you can therefore remove.
Finding the Problematic Query
If you aren’t sure which query is causing the problem, you can use an advanced SQL monitor to search for all the queries executed within a certain timeframe for a selected application. Not only will this provide you with a list of queries, but it will also include the wait times and execution times. As a result, pinpointing the problematic query will be much easier.
An advanced SQL monitor will also allow you to view all your databases from a single dashboard. If you have tens of databases powering separate applications by different vendors, keeping track of what’s going on can be a nightmare. Separately managing MySQL, MS SQL Server, Oracle, and other databases with their distinct properties requires a huge amount of overhead. A unified dashboard can make the life of every database administrator, developer, and system administrator much easier. You can group all databases one place regardless of vendor, application, or usage level.
Ranking Top Offenders
Having a list of all the slow queries that you can improve is extremely valuable even if those queries are not currently impacting your application. Because that can always change in the future. It’s therefore important to review the list regularly and optimize the slowest offenders, starting with the ones you use most.
Performance Over Time
A robust reporting system allows you to see how your database performs over time. You can use it to identify usage peaks (Cyber Monday, weekends, and so forth) and plan for them accordingly by, for example, adding additional resources to your existing CPU and RAM.
Detecting anomalies in real time and receiving alerts is vital to keeping your database and application running. An advanced SQL monitor automatically identifies abnormal patterns (such as low CPU and RAM) and sends alerts when it detects them. You can therefore take action as soon as possible and avoid system outage. Alerts can be sent via email, Slack, SMS, or any direct messaging app.
You can configure which users will receive each kind of alert. For example, you can decide that everyone will receive a notification about a critical alert while only system administrators receive alerts about medium-severity scenarios. Reducing the number of alert recipients is important to stave off “alert fatigue” before it even sets in. If a user gets too many alerts of the same kind on a routine basis, they’ll eventually start to ignore them. And an ignored alert is worse than no alert at all since it makes it harder to notice important alerts that demand immediate action.
SQL Server Activity Monitor Conclusion
An SQL server monitor is an essential tool for every organization that wishes to optimize their database performance, reduce down time, and increase customer satisfaction. It will allow you to identify problematic queries and optimize them, see a unified view of all your SQL databases, monitor them routinely, and see a ranked list of the problematic queries and general data about your database health. Last but not least, it will provide you with automatic alerts every time an anomaly is detected.