Today’s DevOps teams need in-depth monitoring that offers insights into every aspect of the application-delivery chain. When you decide for an application performance monitoring (APM) solution, you can choose between an on-premises approach or SaaS-based solutions (“Monitoring as a Service”). Every deployment option brings its pros and cons or has advantages for special use cases. An installation on-premises for example works best if you want to monitor an intranet that you want to keep isolated.
Which APM deployment option makes most sense for your organization? There‘s no simple answer to this question. A lot depends on your environment and requirements. Let’s explore the points to consider in deciding between SaaS and on-premises monitoring:
With in-house, on-premises systems, all servers and data are physically under your control. When you use SaaS-based monitoring, performance metrics, reliability data, and detected issues are stored in the cloud. If your industry has strong regulatory and policy requirements, SaaS may not be an option for your organization—you may need to keep all such monitoring data on-premises.
To deploy on-premises solutions you need to provide your own hardware and storage in a private datacenter or cloud. You install and configure the monitoring software, databases, and other components of the APM solution. In general, SaaS offerings can be installed and set up within minutes using a self-service system. Some SaaS APM tools even auto-detect your entire server landscape within minutes following installation.
SaaS solutions are typically updated automatically on a frequent basis by the vendors who provide them to deliver support for new technologies and feature enhancements. On-premises installations require that you manage updates yourself and stay current with the release of new product updates. Updates for on-premises solutions typically come out less frequently, which means you sometimes have to wait longer for support of new technologies and bug fixes.
Server and database backups
Maintaining your own servers for an on-premises APM solution requires that you manage the servers, data storage, and data backups yourself. SaaS solutions are maintained and backed up by their vendors.
On-premises software is usually licensed for longer periods of time. This means that the initial investment is often higher, but costs are recouped over time. SaaS-based APM often features “pay as you go” pricing, so you only pay for what you use. This model can be cheaper, but it depends heavily on your usage and your tool vendor’s pricing model. If you run extra servers during periods of peak demand, it makes a big difference if your billing is based on the maximum number of servers you use rather than your actual usage. Because they’re built on cloud infrastructure and often don’t require long-term contracts, SaaS make it much easier for you to opt out of the system and cancel any time. As you aren’t required to purchase and maintain your own hardware, they’re also typically more flexible and easier to scale.
When your monitoring solution runs on-premises it’s often harder to get vendor support because the system may not be reachable from outside your organization. With SaaS-based solutions you can grant access to your tool vendor’s support staff and work with them on resolving issues. This makes the SaaS approach faster and easier if you run into special cases that require vendor support.
With on-premises solutions you must connect to your internal network via VPN to view monitoring data on mobile devices (unless your organization exposes this service to the Internet). Conversely, you can access monitoring data supplied from a SaaS-based solution anywhere you have an Internet connection.
With an on-premises APM solution, you can expect in-depth customizations that suit the exact requirements of your organization. Customization of SaaS solutions on the other hand is limited, and dictated by rules defined by your tool vendor.
If you need to monitor applications that run in a public or hybrid cloud scenario, it’s likely that you’ll also want to run your monitoring in the cloud. SaaS-based solutions enable you to seamlessly monitor cloud-based environments because this is what they’re designed to do. You only need to install agent software on the involved servers.
(No) single point of failure
On-premises solutions are vulnerable to critical problems like power outages and broken network connections, potentially leaving you with no way of receiving performance and availability problem alerts. On the other hand, SaaS monitoring in the cloud runs in a different geographical location and so remains available to send you alerts whenever problems are detected.
Reliability and redundancy
When your APM monitoring solution runs in your own data center, your IT department can determine appropriate service availability levels. SaaS monitoring providers often use software architectures that can be updated without downtime and reach service availability levels of up to 100%. Well-designed SaaS solutions use redundancy to further improve availability. It’s recommended that you take a close look at any SaaS-based solution vendor’s claim of providing “always on” availability.
SaaS tool vendors ensure that needed resources like disk space and CPU will scale up with your demand. This means you won’t need to budget for additional hardware purchases and typically leads to lower total cost of ownership (TCO) with cloud-based SaaS solutions.
Deploying monitoring software in house (on-premises) gives you full control over your data. “Monitoring as a Service” in the cloud brings new possibilities for many monitoring use cases. Depending on your requirements, it could even make sense to use both. Some tool vendors are now providing monitoring solutions that combine the best of both worlds.
With the points covered in this article, you should now know everything you need to consider when deciding which monitoring approach makes most sense for your organization.