Amazon Terminology

Terminology

The following terms defined by Amazon Web Services are used in this help file and defined here for your convenience:

·    Amazon Machine Image (AMI): Amazon Machine Images are machine images stored within Amazon’s infrastructure. An AMI contains the operating system and other software such as ScaleOut StateServer. A pre-packaged AMI that is configured with ScaleOut StateServer is available in the AWS Marketplace.

·    Instance: An instance represents a single running copy of an Amazon Machine Image (AMI).

·    Region: Amazon EC2 allows you to run EC2 instances in multiple geographic locations called regions. When deploying your ScaleOut StateServer instances, it is highly recommended that you select a region with the closest geographical proximity to the majority of your WAN traffic, if applicable.

·    Availability Zone: Every AWS region comprises two or more isolated units of failure within the Amazon Web Services environment called availability zones. A failure in one availability zone is unlikely to propagate to other availability zones within the same region. Resources within the same availability zone will experience lower average network latency than resources that cross availability zones.

·    Key Pair: A key pair is a public-key, private-key encryption system used by Linux-based instances for authentication when logging in to the systems via SSH. A key pair consists of a public key and a private key, and the matching key must be provided to authenticate against a running EC2 instance. An instance may have only one key pair defined at launch, and it may not be changed after launch. An instance without a key pair defined at launch will not be able to grant authentication for advanced administration via remote SSH login.

·    Private IP: A private IP address belongs to a single instance and is only routable from within the instance's associated EC2 Region. Data transfer fees do not apply to data transferred using private IP addresses. When operating within the same EC2 region, use of the private IP Address is preferred to avoid data transfer fees.

·    Public IP: A public IP address belongs to a single instance and is routable from within the EC2 environment, including from other EC2 regions, and from external, Internet locations.

·    Elastic IP (EIP): An Elastic IP (EIP) is a fixed (static) public IP address allocated through EC2 and assigned to a running virtual machine instance. Elastic IPs exist independently of virtual machine instances and may be attached to only a single instance at a time, but they may be reassigned to a different instances with complete transparency to end users. If an Elastic IP is associated with an instance, it invalidates and overrides the original public IP.

·    Security Group: A security group is a named set of allowed inbound network connection rules for EC2 instances. Each security group consists of a list of protocols, ports, and source IP address ranges. A security group can apply to multiple instances, and an instance can be a member of multiple security groups. Security groups may only be assigned to an instance when the instance is being launched. Changes to a security group’s allowed inbound network connections apply to all instances assigned to that Security Group. By default, the SOSS management tools create a new security group for each deployed SOSS store.

·    Placement Group: A cluster placement group is a logical entity that enables creating a cluster of instances with special characteristics, such as high speed networking. Using a placement group, a cluster of instances can have low latency, 10 gigabit Ethernet bandwidth connectivity between instances in the cluster.