This manual describes the installation, configuration, recovery, and upgrade of Rhino VM Automation VMs.
Introduction to the Rhino VM Automation product
Refer to Rhino VM Automation Overview for more details about the Rhino VM Automation solution.
Installation
Installation is the process of deploying VMs onto your host. The Rhino VM Automation VMs must be installed using the SIMPL VM, which you will need to deploy manually first, using instructions for your platform in the SIMPL VM Documentation.
The SIMPL VM allows you to deploy VMs in an automated way. By writing a Solution Definition File (SDF), you describe to the SIMPL VM the number of VMs in your deployment and their properties such as hostnames and IP addresses. Software on the SIMPL VM then communicates with your VM host to create and power on the VMs.
The SIMPL VM deploys images from packages known as CSARs (Cloud Service Archives),
which contain a VM image in the format the host would recognize, such as .ova for VMware vSphere,
as well as ancillary tools and data files.
The VMBC tool creates CSARs suitable for the platform(s) you specify when invoking it.
See the Installation and upgrades page for detailed installation instructions.
Note that all nodes in a deployment must be configured before any of them will start to serve live traffic.
Upgrades
Terminology
The current version of the VMs being upgraded is known as the downlevel version, and the version that the VMs are being upgraded to is known as the uplevel version.
A rolling upgrade is a procedure where each VM is replaced, one at a time, with a new VM running the uplevel version of software. The Rhino VM Automation nodes are designed to allow rolling upgrades with little or no service outage time.
Method
As with installation, upgrades and rollbacks use the SIMPL VM.
The user starts the upgrade process by running csar update on the SIMPL VM.
SIMPL VM destroys, in turn, each downlevel node and replaces it with an uplevel node.
This is repeated until all nodes have been upgraded.
Configuration for the uplevel nodes is uploaded in advance. As nodes are recreated, they immediately pick up the uplevel configuration and resume service.
If an upgrade goes wrong, rollback to the previous version is also supported.
See the Rolling upgrades and patches page for detailed instructions on how to perform an upgrade.
Configuration
The configuration model is "declarative". To change the configuration, you upload a complete set of files containing the entire configuration for all nodes, and the VMs will attempt to alter their configuration ("converge") to match. This allows for integration with GitOps (keeping configuration in a source control system), as well as ease of generating configuration via scripts.
Configuration is stored in a database called CDS, which is a set of tables in a Cassandra database. These tables contain version information, so that you can upload configuration in preparation for an upgrade without affecting the live system.
For the Rhino VM Automation, the CDS database must be provided by the customer. See Setting up CDS for a guide on how to create the required tables.
Configuration files are written in YAML format. Using the rvtconfig tool, their contents can be syntax-checked and verified for validity and self-consistency before uploading them to CDS.
See VM configuration for detailed information about writing configuration files and the (re)configuration process.
Recovery
When a VM malfunctions, recover it using commands run from the SIMPL VM.
Two approaches are available:
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heal, for cases where the failing VM(s) are sufficiently responsive
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redeploy, for cases where you cannot heal the failing VM(s)
In both cases, the failing VM(s) are destroyed, and then replaced with an equivalent VM.
See VM recovery for detailed information about which procedure to use, and the steps involved.
