Instances

The database service deplpoyed on the Tessell portal can be Single-node or Multi-AZ and per node it is assigned an instance.

• For Single-node database service it has one instance.

• For Multi-AZ database service it has multiple instances. One instance is primary and others are replica which provides high availability.

The Instances tab provides the list of all the configured instances for your database service in the tabular format. Each row provides the details of each instance configured per node. Each column of the table provides:

• Name - This field provides the name of the instances assigned for your database service. The name of instances are generated automatically in the incremental order like <name_of_db_service>-default-node-0 for primary , <name_of_db_service>-default-node-1 for replica 1, <name_of_db_service>-default-node-2 for replica 2, and so on as per the number of nodes configured for your database service.

• Status - This field provides the status of each instance. The status of the instances can be:

  Status	Description	Actions allowed
  UP	It displays UP status when the instance is up and running. The connections are allowed once it is in READY status.	* No actions allowed
  DOWN	It displays DOWN status when the instance is down.	* Delete the instance if it is a Read Replica or DR.
  STOPPPED	It displays STOPPED status when the database service is not running and it is completely stopped.	* Start the service
  CREATING	It displays CREATING status when the database service provision is triggered and the process of creating is on or a new instance is added to the existing database service.	* No actions allowed
  DELETING	It displays DELETING status when the database service delete is triggered and the process of deleting is on or an instance is selected to be deleted from the database service. Only RR/DR instances can be deleted from a database service.	* No actions allowed

• Role - This field provides the role of your instance. The possible values are Primary, HA Replica (Automatic Failover), HA Replica (Read replica), and DR (Disaster Recovery).

• Server - This field provides the name of server app where your instance is residing.

• Region/AZ - This field provides the name of the cloud and its region on which your instance is hosted. For all the possible values see supported clouds and regions.

• Parameter Profile - This field provides the name of the parameter profile selected for your instance at the time of provisioning your database service.

• Compute - This field provides the name of the compute shape selected for your instance at the time of provisioning your database service. To view the compute, vCPUS, and memory allocated for this compute shape click on See Details below the compute shape name. For all the possible values see Compute shapes.

• Created - This field provides the date and time on which your instance is created.

• Connection Endpoint - This field provides the connection details for your instance. To view the Service URL, Host, Port, and Username click on the See Details below the connection endpoint name of your instance.

Switch over

The Switch over button on the top right helps to switch any of the available replicas to primary. Selecting Switch over pops up a Switch over to an instance window with the options to switch. Also remember, switching over to an instance may cause some downtime for the service. It provides the list of available replica instances along with its name and status. Select the replica instance to promote as primary and optionally you can add the comments. Select the I understand the consequences checkbox and then click on Switch button. It submits the switching request and to view the progress, select Submitting Request below the service name. After the request is submitted, the Switchover Operation starts to promote the replica to primary. Once completed, the service is again Ready and the updates the Tessell metadata.

Add Node

For any database services, you can add new replicas using the Add Node button on the top right corner. Selecting Read Replica pops up the Add RR Instance window. Provide the details to add the new instance:

• Instance Name - Provide the name for the instance.

• Region - Select any of the available regions from the drop-down list for your instance.

• Availability Zone - Select any of the available availability zones from the drop-down list for your instance.

• VPC - Select any of the available VPC from the drop-down list for your instance.

You can view the code from the bottom of the window and the code is available in different languages like Shell, Python, Go, Java, JavaScript, and PowerShell. You can copy the code using the copy button on the top right corner and also download the code using the download button. Use Close button to return back to the main window.

Select Add Instance to proceed for adding your Read Replica instance.

To add the Read Replica Instance, first the request to add the read replica is submitted, then next it creates the compute instance(s), prepares the primary database to add new replica, configures the replica database with primary database information and lastly it set ups the Availability Machine for the new instance.