Add Server Array Assistant

Add a New Array

There are several different ways to get to the Add Server Array Assistant in the Dashboard. 

• Manage -> Deployments -> Deployment_Name -> Add Array
• Manage -> Arrays -> New Array
• Design -> ServerTemplates -> ServerTemplate_Name -> Add Array

Choose a Cloud

When you click the Add Array button you will be prompted to make a cloud selection. Select the cloud where you will eventually launch the array. (Servers are cloud-specific.)

If you are adding a server array through the Design -> ServerTemplate route or through the Manage -> Arrays > New Array route as shown above, you will need to specify a cloud and deployment.

If you are adding the array directly from a deployment, the "Deployment" row will be hidden and you will only need to specify a cloud.

Note: You will only be able to create a server in the chosen cloud if one of the ServerTemplate's MultiCloud Images supports that cloud.

Make your selections and click Continue.

AWS

• Array Name - Provide a name for the server array.
• MultiCloud Image - Select the MultiCloud Image to be used for the Server Array. The default MultiCloud Image is inherited from the ServerTemplate.
• Instance Type - Select the type of instance that will be launched. By default, the instance type is specified by the chosen MCI, however it can be overwritten if you want to launch a smaller or larger instance type.
• Pricing - Choose either Spot or On Demand for your instances.
• EBS Optimized - Check the box if you want to launch instances that use optimized EBS volumes for better performance. Note: Additional charges from Amazon do apply.

• VPC Subnet - If applicable, specify a subnet of your Virtual Private Cloud (VPC).
• SSH Key - The SSH key that will be used by all servers in the server array.
• Security Group(s) - Select one or more security groups that will be used by all servers launched in the server array.
• Availability Zone - Specify which availability zone(s) new server instances should be launched into.
  • Use the 'any' option if you want the cloud provider to choose which zone the server will be launched. There is no guarantee that the instances will be launched evenly across all zones. For example, all instances could be launched into the same zone. Therefore, if you want instances to be evenly distributed across all zones, you should use the 'weighted' option instead.
  • If "Weighted across availability zones" is chosen, you will see a green message: "You can set weights on the Array Details tab." There, you can set probability percentages of instance allocation that total 100% and specify a max number of instances for each availability zone.

• Machine Image - The AMI that will be used to build the machine. RightScale will only support instances launched with one of our RightImages. We recommend using ServerTemplates with RightImages.
• Ramdisk Image - Select a Ramdisk image of your choice. (optional)
• Kernel Image - Select a kernel image of your choice. (optional)
• Ec2 user data - This information is passed to the instance using the EC2 user launch data mechanism which is limited to 16KB of data. The best way to pass configuration data into instances is with RightScripts, but this user data field is sometimes useful for testing purposes.

AWS Pricing

With an AWS server, you have the option to choose the type of pricing for your instance. The default is On-Demand, with the current On-Demand price listed right below. If you select Spot from the Pricing dropdown, the current spot prices will be viewable for each Availability Zone.

CloudStack-based Clouds

• Array Name - Provide a name for the server array.
• MultiCloud Image - Select the MultiCloud Image to be used for the Server Array. The default MultiCloud Image is inherited from the ServerTemplate.
• Instance Type - Specify the type (size) of instance to launch. For a CloudStack cloud, you must manually select the instance type if using a RightScale-created MultiCloud Image; RightScale MCIs do not specify a default instance type for CloudStack clouds.

• Security Group - Security group that will be used by all servers in the server array.
• Datacenter / Zone - The regional datacenter in the cloud (Datacenter and Zone are synonymous). A cloud will often have multiple Datacenters which can help when architecting a highly available deployment.
  • If "Weighted across availability zones" is chosen, you will see a green message: "You can set weights on the Array Details tab." There, you can set probability percentages of instance allocation that total 100% and specify a max number of instances for each availability zone.
• Subnets - Subnet of the network in which the server is deployed.

• Machine Image - The image that will be used to build the machine. RightScale will only support instances launched with one of our RightImages. We recommend using ServerTemplates with RightImages.
• User data - This information is passed to the instance. The best way to pass configuration data into instances is with RightScripts, but this user data field is sometimes useful for testing purposes.

Google Compute Engine

• Array Name - Provide a name for the server array.
• MultiCloud Image - Select the MultiCloud Image to be used for the Server Array. The default MultiCloud Image is inherited from the ServerTemplate.
• Instance Type - Specify the type (size) of instance to launch.

• Security Group - Security group that will be used by all servers in the server array.
• Datacenter / Zone - The regional datacenter in the cloud (Datacenter and Zone are synonymous). A cloud will often have multiple Datacenters which can help when architecting a highly available deployment.
  • If "Weighted across availability zones" is chosen, you will see a green message: "You can set weights on the Array Details tab." There, you can set probability percentages of instance allocation that total 100% and specify a max number of instances for each availability zone.

• Machine Image - The image that will be used to build the machine. RightScale will only support instances launched with one of our RightImages. We recommend using ServerTemplates with RightImages.
• User data - This information is passed to the instance. The best way to pass configuration data into instances is with RightScripts, but this user data field is sometimes useful for testing purposes.

Rackspace

• Array Name - Provide a name for the server array.
• MultiCloud Image - Select the MultiCloud Image to be used for the Server Array. The default MultiCloud Image is inherited from the ServerTemplate.
• Instance Type - Specify the type (size) of instance to launch.

• Machine Image - The image that will be used to build the machine. RightScale will only support instances launched with one of our RightImages. We recommend using ServerTemplates with RightImages.

Alert-based Arrays

• Status - The status of the server array. If active, the server array is enabled for scaling actions. For alert-based arrays, if you disable an array with running instances, the server array will no longer be able to scale up or down, but the instances will continue to run until they are manually terminated. It's recommended that you keep the server array disabled until you have manually launched and tested instances into the array because you do not want to enable an array with a minimum count of 10 and have 10 servers strand in booting because there was an error in the configuration.
• Min Count - The minimum number of active servers that must exist at all times in the server array. If you are setting up a multi-tier deployment, it's strongly recommended that you have a minumum count of two (2) for redundancy purposes.
• Max Count - The maximum number of active servers that must exist at all times in the server array.
• Array Type - Specify alert-based or queue-based arrays. Secondary options will change accordingly.
  • For Weighted Arrays - If "Weighted across availability zones" was chosen in the previous Server Details tab, you can set probability percentages of instance allocation that total 100% and specify a max number of instances for each availability zone. It's strongly recommended that you distribute the instances in the array across multiple zones (if available) to protect against a single zone failure from affecting the entire application tier.
• Decision Threshold - Percent of votes that must be made by all application servers in order to trigger an alert escalation and resize the server array. Typically, you will want to specify that a majority of your application tier is experiencing a problem before you want a scaling action to occur. If you set the threshold too low, you may experience premature and unnecessary scaling actions.
• Choose Voters by Tag - The Voters Tag that RightScale will use in order to determine when to scale up/down. For example, the elasticity daemon will look for all servers with the specified tag (e.g. MyArray) when counting the number of votes for a scale/up action. When the number of votes for a particular scaling action (e.g. grow) exceeds the decision threshold, the server array will automatically scale based on the specified resize parameters. By default, the name of the server array will be used as the voter tag, however you can specify a different string if desired. If you use the nickname of the server array as the voter tag, it's recommended that you use a simple string. (e.g. my-tag) 
• Resize up by - Number of servers that should be added from a server array when a resize action occurs. Typically, you will want to use a more agressive value for scaling up and a more conservative value for scaling down.
• Resize down by - Number of servers that should be removed from a server array when a resize action occurs.
• Resize calm time - Time (in minutes) that must pass before another action can be taken on the server array. The calm time prevents an array from being resized too frequently. Be sure to allow enough time for the server to become operational and start taking load. You should always test the server array and determine the nominal launch time for your configuration in order to determine the appropriate calm time for your application. Clouds, instance sizes, and the time required to complete all the boot scripts are all factors that should be taken into consideration.

Queue-based Arrays (EC2-only)

• Status -  The status of the server array. If active, the server array is enabled for scaling actions. 
• Min Count - The minimum number of active servers that must exist at all times in the server array.
• Max Count - The maximum number of active servers that must exist at all times in the server array.
• Array Type - Specify alert-based or queue-based arrays. Secondary options will change accordingly.
• Elasticity Function - Defines how the server array should grow/shrink. (size or age)
• Items per Instance - Max number of items in queue per operational instance.
• Indicator Queue - Select the input SQS queue that contains all of the job tasks.
• Audit Queue - Select the audit SQS queue that will store audit entries.