Merge pull request #545 from QuinnyPig/updates-preinvent

Updates for recent announcements

README.md

@@ -765,7 +765,7 @@ S3
 -	🔸After uploading, any change that you make to the object causes a full rewrite of the object, so avoid appending-like behavior with regular files.
 -	🔸Eventual data consistency, as discussed above, can be surprising sometimes. If S3 suffers from internal replication issues, an object may be visible from a subset of the machines, depending on which S3 endpoint they hit. Those usually resolve within seconds; however, we’ve seen isolated cases when the issue lingered for 20-30 hours.
 -	🔸**MD5s and multi-part uploads:** In S3, the [ETag header in S3](http://docs.aws.amazon.com/AmazonS3/latest/API/RESTCommonResponseHeaders.html) is a hash on the object. And in many cases, it is the MD5 hash. However, this [is not the case in general](http://stackoverflow.com/questions/12186993/what-is-the-algorithm-to-compute-the-amazon-s3-etag-for-a-file-larger-than-5gb) when you use multi-part uploads. One workaround is to compute MD5s yourself and put them in a custom header (such as is done by [s4cmd](https://github.com/bloomreach/s4cmd)).
--	🔸**Incomplete multi-part upload costs:** Incomplete multi-part uploads accrue [storage charges](http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuoverview.html#mpuploadpricing) even if the upload fails and no S3 object is created. [Amazon](http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuoverview.html#mpu-abort-incomplete-mpu-lifecycle-config) ([and](http://www.deplication.net/2016/06/aws-tip-save-s3-costs-with-abort.html) [others](https://www.sumologic.com/aws/s3/s3-cost-optimization/)) recommend using a lifecycle policy to clean up incomplete uploads and save on storage costs.
+-	🔸**Incomplete multi-part upload costs:** Incomplete multi-part uploads accrue [storage charges](http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuoverview.html#mpuploadpricing) even if the upload fails and no S3 object is created. [Amazon](http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuoverview.html#mpu-abort-incomplete-mpu-lifecycle-config) ([and](http://www.deplication.net/2016/06/aws-tip-save-s3-costs-with-abort.html) [others](https://www.sumologic.com/aws/s3/s3-cost-optimization/)) recommend using a lifecycle policy to clean up incomplete uploads and save on storage costs. Note that if you have many of these, it may be worth investigating whatever's failing regularly. 
 -	🔸**US Standard region:** Previously, the us-east-1 region (also known as the US Standard region) was replicated across coasts, which led to greater variability of latency. Effective Jun 19, 2015 this is [no longer the case](https://forums.aws.amazon.com/ann.jspa?annID=3112). All Amazon S3 regions now support read-after-write consistency. Amazon S3 also renamed the US Standard region to the US East (N. Virginia) region to be consistent with AWS regional naming conventions.
 - 🔸**S3 authentication versions and regions:** In newer regions, S3 [only supports the latest authentication](https://docs.aws.amazon.com/AmazonS3/latest/dev/UsingAWSSDK.html#specify-signature-version). If an S3 file operation using CLI or SDK doesn't work in one region, but works correctly in another region, make sure you are using the latest [authentication signature](https://docs.aws.amazon.com/AmazonS3/latest/API/sig-v4-authenticating-requests.html).
 
@@ -779,7 +779,7 @@ As an illustration of comparative features and price, the table below gives S3 S
 | **S3 IA**       | Eleven 9s              | 99.9%                   | **99%**          | $12.50                                                                                                                   | $1                            | $10                            |
 | ~~**S3 RRS**~~      | ~~**99.99%**~~             | ~~99.99%~~                  | ~~99.9%~~            | ~~$24 (first TB)~~                                                                                                                      | ~~$0.40~~                         | ~~$5~~                             |
 | **S3 Standard** | Eleven 9s              | 99.99%                  | 99.9%            | $23                                                                                                                     | $0.40                         | $5                             |
-| **EBS**         | **99.8%**              | Unstated                | 99.95%           | $25/$45/**$100**/$125+ ([sc1/st1/**gp2**/io1](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSVolumeTypes.html)\) |                               |                                |
+| **EBS**         | **99.8%**              | Unstated                | 99.99%           | $25/$45/**$100**/$125+ ([sc1/st1/**gp2**/io1](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSVolumeTypes.html)\) |                               |                                |
 | **EFS**         | “High”                 | “High”                  | –                | $300                                                                                                                     |                               |                                |
 | **EC2 d2.xlarge instance store**  | Unstated | Unstated                | –                | $25.44                                                                                                                   | $0                            | $0                             |
 
@@ -791,8 +791,8 @@ EC2
 ### EC2 Basics
 
 -	📒 [Homepage](https://aws.amazon.com/ec2/) ∙ [Documentation](https://aws.amazon.com/documentation/ec2/) ∙ [FAQ](https://aws.amazon.com/ec2/faqs/) ∙ [Pricing](https://aws.amazon.com/ec2/pricing/) (see also [ec2instances.info](http://www.ec2instances.info/)\)
--	**EC2** (Elastic Compute Cloud) is AWS’ offering of the most fundamental piece of cloud computing: A [virtual private server](https://en.wikipedia.org/wiki/Virtual_private_server). These “instances” can run [most Linux, BSD, and Windows operating systems](https://aws.amazon.com/ec2/faqs/#What_operating_system_environments_are_supported). Internally, they use [Xen](https://en.wikipedia.org/wiki/Xen) virtualization.
--	The term “EC2” is sometimes used to refer to the servers themselves, but technically refers more broadly to a whole collection of supporting services, too, like load balancing (CLBs/ALBs), IP addresses (EIPs), bootable images (AMIs), security groups, and network drives (EBS) (which we discuss individually in this guide).
+-	**EC2** (Elastic Compute Cloud) is AWS’ offering of the most fundamental piece of cloud computing: A [virtual private server](https://en.wikipedia.org/wiki/Virtual_private_server). These “instances” can run [most Linux, BSD, and Windows operating systems](https://aws.amazon.com/ec2/faqs/#What_operating_system_environments_are_supported). Internally, they've used a heavily modified[Xen](https://en.wikipedia.org/wiki/Xen) virtualization. That said, new instance classes are being introduced with a KVM derived hypervisor instead. So far, this is limited to the C5 instance families.
+-	The term “EC2” is sometimes used to refer to the servers themselves, but technically refers more broadly to a whole collection of supporting services, too, like load balancing (CLBs/ALBs/NLBs), IP addresses (EIPs), bootable images (AMIs), security groups, and network drives (EBS) (which we discuss individually in this guide).
 -	💸**[EC2 pricing](https://aws.amazon.com/ec2/pricing/)** and **[cost management](#ec2-cost-management)** is a complicated topic. It can range from free (on the [AWS free tier](https://aws.amazon.com/free/)) to a lot, depending on your usage. Pricing is by instance type, by second or hour, and changes depending on AWS region and whether you are purchasing your instances [On-Demand](https://aws.amazon.com/ec2/pricing/on-demand/), on the [Spot market](https://aws.amazon.com/ec2/spot/) or pre-purchasing ([Reserved Instances](https://aws.amazon.com/ec2/pricing/reserved-instances/)).
 - **Network Performance:** For some instance types, AWS uses general terms like Low, Medium, and High to refer to network performance. Users have done [benchmarking](http://stackoverflow.com/questions/18507405/ec2-instance-typess-exact-network-performance) to provide expectations for what these terms can mean.
 
@@ -974,7 +974,7 @@ EBS
 ### EBS Gotchas and Limitations
 
 -	❗EBS durability is reasonably good for a regular hardware drive (annual failure rate of [between 0.1% - 0.2%](http://aws.amazon.com/ebs/details/#availabilityanddurability)). On the other hand, that is very poor if you don’t have backups! By contrast, S3 durability is extremely high. *If you care about your data, back it up to S3 with snapshots.*
--	🔸EBS has an [**SLA**](http://aws.amazon.com/ec2/sla/) with **99.95%** uptime. See notes on high availability below.
+-	🔸EBS has an [**SLA**](http://aws.amazon.com/ec2/sla/) with **99.99%** uptime. See notes on high availability below.
 -	❗EBS volumes have a [**volume type**](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSVolumeTypes.html) indicating the physical storage type. The types called “standard” (**st1** or **sc1**) are actually old spinning-platter disks, which deliver only hundreds of IOPS — not what you want unless you’re really trying to cut costs. Modern SSD-based **gp2** or **io1** are typically the options you want.
 -	❗When restoring a snapshot to create an EBS volume, blocks are lazily read from S3 the first time they're referenced. To avoid an initial period of high latency, you may wish to use `dd` or `fio` as per the [official documentation](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-restoring-volume.html).