About Discovery Manager - Servers
The Discovery Manager does not disrupt imported instances in any way. The entire process is handled through the cloud platform’s APIs.
The Discovery Manager is a tool that discovers and imports existing cloud server instances onto the Scalr Cloud Management Platform. Once the instances are imported, they are mapped to Farms and Farm Roles, and share many of the benefits of Scalr provisioned infrastructure. Normally, cloud infrastructure provisioned through the Scalr self-service catalog uses the Scalarizr agent. The agent allows Scalr to provide performance metrics and perform various automation tasks. There is also the option to create Roles that don’t use the agent. This means management is limited to actions that can be performed via cloud APIs on instances that do not use the scalarizr agent. Instances of "agentless" roles still have many of the benefits of Scalr, but lose some automation capabilities. To avoid disruption, instances imported through the Discovery Manager are agentless by default but may be converted to Scalr agent managed instances if desired.
Scalarizr agent capability overview:
|Launch, Terminate, Suspend, Resume||Yes||Yes|
|Security Group management||Yes||Yes|
No (Partially possible via external metrics or Date/Time rules)
|Storage Volume addition||No||Yes|
|Software Firewall/ iptables management||No||Yes|
How to use the Discovery Manager - Servers
The Discovery Manager uses a simple, straightforward importing process.
Step 1: Discovery
In the relevant Environment, from the main menu, select Discovery Manager, then Servers.
You will then see a list of discovered instances. Be sure to change the region if necessary in order to discover the correct instances.
Step 2: Import
Select the instance that you would like to import and click “Import”. Only running instances can be imported.
Step 3: Register Image in Scalr
Please note: When importing running VMware instances, Scalr will allow for the machine to be imported with a placeholder "VMware System Image" as the template used to build the machine may or may not exist at the time of discovery. After successful discovery, be sure to create a new snapshot (template) from the running server to serve as the image for the new Role. Scalr may then use the new snapshot(template) to launch more instances of the Role.
Every Role in Scalr uses an image, images need to be registered in the catalog. If this has not yet been completed, click on the “Register Image in Scalr” link to go through a quick image registration wizard.
NOTE: When registering an image, make sure to get the OS family and version right, as choosing the wrong settings could potentially cause issues.
Step 4: Create a Role based on the registered image
Once the image is registered, a Role needs to be created. This Role will be used as the Farm Role later on, and can be used as a template for future instances of the imported server.
If a relevant Role does not yet exist, click the “Create Role With Image Above” link.
Clicking “Create Role With Image Above” will take you to the standard Role Creation screen. When you save the Role you’ll be taken back to the Discovery Manager.
Step 5: Map imported instances to Farm and Farm Role
Once the Role is created, select a running Farm from the drop-down menu, and then select a Farm Role within that Farm. If a relevant Farm Role does not exist, you’ll have the option to create one.
NOTE: When creating a new Farm Role, make sure you select the correct subnet for VPC instances.
Once you’ve selected your Farm and Farm Role, click “Continue” at the bottom of the page.
Step 6: Done!
You will be prompted to review and confirm the configuration. Once you hit “Confirm”, the instance will be instantly imported!
NOTE: Whenever you import instances into a Farm Role, new or existing, auto-scaling will be disabled on it. This default is to avoid a situation where the import of new instances violates the scaling quota for the Farm Role, resulting in instance termination. Once the importing process is done, you can go to the relevant Farm to review and re-enable auto-scaling.
Deploy Scalr Agent
After importing a running instance, you will see it listed in the Servers List but there will be no agent detected
Using the Server > Actions menu, select Deploy Scalr Agent.
You may be presented with an error that notes you must be using a newer agent version for this Farm.
If so, navigate to the Advanced tab for your Farm and ensure Repository is set to "Latest", or to a repository that contains agent version 4.7.13 or newer.
You will then be presented with instructions to install the agent and then launch it. If you have not already done so, be sure to apply Security Group or other firewall rules that allow communication over TCP port 8013 on the instance.
After executing the provided commands on the server, click Confirm Scalarizr Launch to begin the agent deployment process.
Click Continue and then Close when prompted.
After successful Scalr agent deployment, the agent status and version will be displayed in the Server List. The agent controlled server will now fully benefit from all Scalr management features including automation, orchestration, and monitoring.