1. Introduction
There is no perfect software solution for every user and every application.
What works for one person may be too much or too little, too simple or too complex for another.
That is why Checkmk is available in a number of different editions.
These differ above all in their range of features and suitability for specific areas of application.
In the following we would like to introduce 
Checkmk Ultimate (formerly Checkmk Cloud (Self-hosted)), one of the commercial editions.
2. Overview of Checkmk Ultimate
Building on Checkmk Pro, Checkmk Ultimate primarily offers improvements for comprehensive monitoring of hybrid environments in which hosts are located both in data centers and in the cloud.
Support when moving applications and processes to the cloud, i.e. in so-called lift and shift scenarios, has already been integrated into all Checkmk editions — which simplifies the implementation of Amazon Web Services (AWS), Microsoft Azure and the Google Cloud Platform (GCP) monitoring. In addition, Checkmk Ultimate offers extra cloud-specific check plug-ins and dashboards. Besides cloud integration, Checkmk Ultimate scores with enhanced security (such as the Checkmk agent in push mode), automation (through auto-registration of hosts), and comprehensive application observability via the OpenTelemetry standard.
Checkmk Ultimate is the basis for the on-premises edition 
Checkmk Ultimate with Multi-Tenancy on the one hand, and on the other for Checkmk Cloud, which provides Checkmk as Software as a Service (SaaS) in the cloud.
An overview of the functions of Checkmk Cloud can be found in the Checkmk Cloud User Guide.
Complementing the edition comparison and the presentation of Checkmk Ultimate on our website, this article explains the differences on a technical level and thus tries to be a complementary support for decision making when choosing a Checkmk edition.
3. Additional functions
The key features of Checkmk Ultimate that differentiate it from other editions:
Only Checkmk Ultimate is available through the Microsoft Azure and AWS marketplaces.
Advanced check plug-ins:
Checkmk Ultimate includes additional cloud-specific check plug-ins for monitoring Amazon Web Services (AWS), Microsoft Azure and the Google Cloud Platform (GCP).Cloud-specific dashboards:
In Checkmk Ultimate, there are specific dashboards for AWS, Microsoft Azure and GCP.Configuration of a push agent:
In all on-premises editions, the Checkmk server initiates communication with a host and requests the data from the Checkmk agent — in the so-called pull mode. With Checkmk Ultimate you can additionally use the push mode.Auto-registration of hosts:
In Checkmk Ultimate, you can have hosts created automatically that have a Checkmk agent installed. This includes registering the agent with the Checkmk server, establishing a TLS-encrypted connection, creating the host, performing a service discovery and activating the changes, so that the host is added to the monitoring environment — all fully automatically. Auto-registration works for pull and push agents.
4. Upgrading to Checkmk Ultimate
You can upgrade Checkmk Community or Checkmk Pro to Checkmk Ultimate. To do so, follow the upgrade description.
5. Differences of the components in detail
5.1. The monitoring interface
| Function | Description |
|---|---|
Cloud dashboards |
In monitoring, you will find the dedicated dashboards for AWS, Azure and GCP. |
5.2. The monitoring agents
| Function | Description |
|---|---|
Push mode |
The Checkmk agent for Linux and for Windows can be configured and used in push mode. You configure the mode (push or pull) in the Monitoring agents section in the host or folder properties. Push mode relies on the Agent Controller and is therefore not available in the agent’s legacy mode. |
Auto-registration |
You have the option to create hosts automatically during registration with the so-called auto-registration. The Agent registration rule set is used to configure the Checkmk site. The auto-registration also requires the Agent Controller. |
Agent Bakery |
You can additionally use the Agent Bakery to provide agent packages with a configuration for auto-registration. The rule for the Agent Bakery is named Agent controller auto-registration. These packages perform registration automatically after installation. |
Agent registration permissions |
The predefined role |
5.3. Connections
| Function | Description |
|---|---|
Grafana |
You can install the Grafana plug-in directly from the Grafana catalog, making it easy to embed the integration into your cloud environment. |
5.4. Deployment
| Feature | Description |
|---|---|
Availability in the Azure and AWS Marketplaces |
Checkmk Ultimate is available for installation in the marketplaces of Microsoft Azure and AWS. The Azure and AWS articles will guide you through the image setup. |
Testing the edition |
You can test Checkmk Ultimate in full functionality for 30 days without obligation. On a small scale, i.e. with one site and up to 750 services, you can also run Checkmk with Checkmk Ultimate on a permanent basis without requiring a subscription. |
5.5. Additional functions
| Function | Description |
|---|---|
Check plug-ins for AWS |
There are additional check plug-ins for the AWS Cloud products AWS Lambda, Elastic Container Service (ECS), Route 53, CloudFront, ElastiCache for Redis and Simple Notification Service (SNS). |
Check plug-ins for Azure |
There are additional check plug-ins for the Azure products Application Gateway and Recovery Services vaults. |
Check plug-ins for GCP |
There are additional check plug-ins for the Google Cloud products Cloud Functions, Cloud Run and Memorystore for Redis. |
OpenTelemetry |
You can receive OpenTelemetry metrics and process them in the monitoring. In the dynamic host management, there is a separate connection type for setting up an OpenTelemetry connection. |