Cloud Computing Info

Simple Queue Service (SQS)

SQS is Amazon’s message queuing service. It works much like IBM’s MQ Series, JMS or Oracle AQ. Pop in a message and one or more recipients can pop it out. SQS is completely open so any internet connected computer can call a web service and add or remove a message.

Because SQS is API based, you can write an interface to it in the language of your choice. There are several free Java, Ruby and PHP interfaces available (that I know of) with more coming.

Elastic Compute Cloud (EC2)

Elastic Block Storage (EBS)

For most of its life in beta, EC2 offered only two kinds of storage, AMI based transient storage and S3. The transient storage was mounted as a filesystem and S3 was used for backup. To save data during downtime for instances, data had to first be saved off to S3 and the instance brought down. When the instance was brought back up, data was restored from S3. It was a painful process.

Enter EBS, the Elastic Block Store.

Simple Storage Service (S3)

Cost

Storage is cheaper in the US than in Europe. If you are based in Europe, you may want to decide which is more important when getting or adding data: price or latency.

Table 3: S3 Storage Costs

Table 4: S3 Data Transfer Costs

Table 5: S3 Request Costs

These prices are accurate as of the time of writing them.

Simple Storage Service (S3)

Security

Write and delete access to buckets and objects is controlled via Access Control Lists (ACL). You can assign read permissions to any object to specific users. You can also make an object public to grant access to anyone.

Transfer into and out of S3 can utilize SSH which will encrypt data. This prevents any “over the wire” interception of your data. Data at rest is not encrypted and Amazon recommends that users encrypt any sensitive data with their encryption tool of choice.

Simple Storage Service (S3)

The AWS S3 service is an API driven storage service. The API provides get, put and delete. Data is stored using a bucket concept that is not unlike directories and sub-directories. A bucket can hold one or more buckets and one or more objects (i.e. files). You can nest buckets as many levels deep as required by your application or other needs. Objects can be up to 5GB per and you can store an unlimited number of objects.

At the top level is a global bucket. All S3 accounts share the global bucket.