EC2

Amazon FSx for Windows

- Amazon FSx for Windows File Server provides a fully managed native Microsoft Windows file system so you can easily move your Windows - based applications that require file storage to AWS. Amazon FSx is bulit on Windows Server.

Spot Fleets

- A Spot Fleet is a collection of Spot Instances and, optionally, On-Demand Instances. - The Spot Fleet attempts to launch the number of spot instances and on-demand instances to meet the target capacity you specified in the Spot Fleet Request. The request for Spot Instances is fulfilled if there is available capacity and the maximum price you specified in the request exceeds the current Spot Price. The Spot Fleet also attempts to maintain its target capacity fleet if your Spot Instances are interrupted. - Spot Fleets will try and match the target capacity with your price restraints : 1. Set up different launch pools. Define things like EC2 instance type, OS, and AZ. 2. You can have multiple launch pools, and the fleet will choose the best way to implement depending on the strategy you define. 3. Spot fleets will stop launching instances once you reach your price threshold or capacity desire.

Clustered Placement Group

- A cluster placement group is a grouping of instances within a single AZ. Placement groups are recommended for applications that need low network latency, high network throughput, or both. - Only certain instances can be launched in to a Clustered Placement Group.

Exam Tips

- A clustered placement group can't span multiple AZ. A spread and partitioned group can. - The name you specify for a placement group must be unique within your AWS account. - Only certain types of instances can be launched in a placement group.(Compute Optimized, GPU, Memory Optimized, Storage Optimized). - AWS recommends homogenous instances within clustered placement groups. - You can't merge placement groups. - You can move an existing instance into a placement group. Before you move the instance, the instance must be in stopped state. You can move or remove an instance using the AWS CLI or an AWS SDK, you cannot do it via the console yet.

CloudTrail

- AWS CloudTrail increases visibility into your user and resource activity by recording AWS Management Console Actions and API Calls. You can identify which users and accounts called AWS, the source IP address from which the calls were made, and when the calls occurred. - CloudTrail monitors API calls in the AWS Platform.

HPC on AWS : Data Transfer : Direct Connect

- AWS Direct Connect is a cloud service solution that makes it easy to establish a dedicated network connection from your on-premises to AWS. Using AWS Direct Connect, you can establish private connectivity between AWS and your data center, office, or colocation environment - which, in many cases, can reduce your network costs, increase bandwidth throughput, and provide a more consistent network experience than internet-based connections.

AWS WAF behaviour

- AWS WAF allows 3 different behaviours : 1. Allow all requests except the ones you specify. 2. Block all requests except the ones you specify. 3. Count the requests that match the properties you specify.

AWS WAF

- AWS WAF is a web application firewall that lets you monitor the HTTP and HTTPS requests that are forwarded to Amazon CloudFront, an Application Load Balancer or API Gateway. - AWS WAF also lets you control access to your content. - It is a layer 7(Application layer) firewall. Ex Query String parameter : http://acloud.guru?id=1001&name=ryan - You can configure conditions such as what IP addresses are allowed to make this request or what query string parameters need to be passed for the request to be allowed. - Then the application load balancer or CloudFront or API Gateway will either allow this content to be received or to give a HTTP 403 Status Code.

EBS vs Instance Store

- All AMI's are categorized as either backed by Amazon EBS or backed by Instance Store. - For EBS Volumes : The root device for an instance launched from the AMI is an Amazon EBS Volume created from an Amazon EBS Snapshot. - For Instance Store Volumes : The root device for an instance launched from the AMI is an instance store volume created from a template stored in Amazon S3. - For instance store volumes if you need additional instance store volumes you have to add them while creating/launching the instance, you can not add them later once a instance is launched.

CloudWatch 101

- Amazon CloudWatch is a monitoring service to monitor your AWS resources, as well as the applications that you run on AWS. - CloudWatch monitors performance. - ClouWatch can monitor things like : a. Compute : 1. EC2 Instances 2. Autoscaling Groups 3. Elastic Load Balancers 4. Route53 Health Checks b. Storage and Content Delivery : 1. EBS volumes 2. Storage Gateways 3. CloudFront

Spot Instances

- Amazon EC2 Spot Instances let you take advantage of unused EC2 capacity in the AWS cloud. Spot Instances are available up to a 90% discount compared to On-Demand prices. You can use spot instances for various stateless, fault-tolerant, or flexible applications, such as big data, containerized workloads, CI/CD, web servers, high performance computing(HPC), and other test and development workloads.(Like Stock Market). - To use Spot Instances, you must first decide on your maximum Spot Price. The instance will be provisioned so long as the Spot price is BELOW your maximum Spot price. - The hourly Spot Price varies depending on capacity and region. - If the Spot price goes above your maximum, you have two minutes to choose whether to stop or terminate your instance.

Elastic File System(EFS)

- Amazon EFS is a file storage service for Amazon EC2 instances. Amazon EFS is easy to use and provides a simple interface that allows you to create and configure file systems quickly and easily. - With Amazon EFS, storage capacity is elastic, growing and shrinking automatically as you add and remove files, so your applications have the storage they need, when they need it. - Its similar to EBS except where you've got EBS you can only mount your virtual disk to one EC2 instance, you cannot have 2 EC2 instances sharing an EBS volume. However you can have them sharing an EFS volume.

EBS

- Amazon Elastic Block Store (EBS) provides persistent block storage volumes for use with Amazon EC2 instances in the AWS cloud. Each Amazon EBS volume is automatically replicated within its Availability Zone to protect you from component failure, offering high availability and durability. - 5 different types : 1. General Purpose (SSD) - gp2 2. Provisioned IOPS (SSD) - io1 3. Throughput Optimised Hard Disk Drive - st1 4. Cold Hard Disk Drive - sc1 5. Magnetic - standard

EC2

- Amazon Elastic Compute Cloud(EC2) is a web service that provides resizable compute capacity in the cloud. Amazon EC2 reduces the time required to obtain and boot new server instances to minutes, allowing you to quickly scale capacity, both up and down, as your computing requirements change.

ENI

- An ENI is simply a virtual network card for your EC2 instances. It allows : 1. A primary private IPv4 address from the IPv4 address range of your VPC. 2. One or more secondary private IPv4 addresses from the IPv4 address range of your VPC. 3. One Elastic IP address (IPv4) per private IPv4 address. 4. One public IPv4 address. 5. One or more IPv6 addresses. 6. One or more security groups. 7. A MAC address. 8. A source/destination check flag. 9. A description. - Scenarios for ENI : 1. Create a management network 2. Use network and security appliances in your VPC. 3. Create dual-homes instances with workloads/roles on distinct subnets. 4. Create a low budget , high availability solution.

EFA

- An Elastic Fabric Adapter(EFA) is a network device that you can attach to your amazon EC2 instance to accelerate High Performance Computing(HPC) and Machine Learning applications. - EFA provides lower and more consistent latency and higher throughput than the TCP transport traditionally used in cloud based HPC systems. - EFA can use OS-bypass. OS-bypass enables HPC and ML applications to bypass the OS kernel and to communicate directly with EFA device. It makes it a lot faster with a lot lower latency. Not supported with windows currently, only Linux.

Amazon's EBS volumes are ________.

- Block Based Storage - EBS, EFS, and FSx are all storage services based on block storage.

Security Groups

- Changes to Security Group will take effect immediately. - Security Groups are STATEFULL i.e., when you create an inbound rule and outbound rule is created automatically. - Cannot block/blacklist a particular port or IP Address. - By default all inbound traffic is blocked. - All outbound traffic is allowed. - You can have any number of EC2 instances within a security group. - You can have multiple security groups attached to EC2 Instances. - You can specify allow rules, but not deny rules. - You cannot block specific IP addresses using Security Groups, instead use Network Access Control Lists (NACL).

Exam Tips

- CloudWatch is used for monitoring performance. - CloudWatch can monitor most of AWS as well as your applications that run on AWS. - CloudWatch with EC2 will monitor events every 5 minutes by default. - You can have 1 minute intervals by turning on detailed monitoring. - You can create CloudWatch alarms which trigger notifications. - CloudWatch si all about performance. CloudTrail is all about auditing.

HPC on AWS : Compute and Networking

- Compute and Networking services that allow us to achieve HPC on AWS : 1. EC2 instances that are GPU or CPU optimized. 2. Enhanced Networking 3. EC2 Fleets(Spot Instances or Spot Fleets) 4. Elastic Network Adapters. 5. Placement Groups(cluster placement groups) 6. Elastic Fabric Adapters.

In order to enable encryption at rest using EC2 and Elastic Block Store, you must ________.

- Configure encryption when creating the EBS volume. - The use of encryption at rest is default requirement for many industry compliance certifications. Using AWS managed keys to provide EBS encryption at rest is a relatively painless and reliable way to protect assets and demonstrate your professionalism in any commercial situation.

What can I do with ClouWatch

- Dashboards : Creates awesome dashboards to see what is happening with your AWS environment. - Alarms : Allows you to set Alarms that notify you when particular thresholds are hit. - Events : CloudWatch events helps you to respond to state changes in your AWS resources. - Logs : CloudWatch logs helps you to aggregate, monitor, and store logs.

Different services we can use to achieve HPC on AWS

- Data Transfer - Compute and Networking - Storage - Orchestration and automation

Enhanced Networking

- Depending on your instance type, enhanced networking can be enabled using : 1. Elastic Network Adapter(ENA), which supports network speeds of up to 100 Gbps for supported instance types. OR 2. Intel 82599 Virtual Function(VF) interface, which supports network speeds of up to 10 Gbps or supported instance types. This is typically used on older instances. - In any scenario question you probably want to choose ENA over VF if given the option.

EBS Volume and Snapshots

- EBS volume is in the same availability zone as your EC2 instance. - How to move EBS volume to another availability zone : 1. Create a snapshot of that volume. 2. From that snapshot create an AMI image. 3. From that AMI image you can launch another EC2 instance in another availability zone. OR 1. We can also copy AMI and launch it in another region (or AZ). - When you terminate an EC2 instance by default the root device volume will also be terminated however, the additional volumes attached to that EC2 instance will persist(not deleted).

Exam Tips

- EC2 Hibernate preserves the in-memory RAM on persistent storage(EBS). - Much faster to boot up because you do not need to reload the OS. - Instance RAM must be less than 150GB. - Instance families include C3, C4, C5, M3, M4, M5, R3, R4, R5 and t2 micro. - Available for windows, linux 2 AMI and Ubuntu. - Instances can't be hibernated for more than 60 days. - Available for On-Demand instances and Reserved Instances.

Exam Tips

- EFS supports the Network File System version 4(NFSv4) protocol. - You only pay for the storage you use(no pre-provisioning required). - Can scale up to the petabytes. - Can support thousands of concurrent NFS connections. - Data is stored across multiple AZ's within a region. - Read After Write consistency. - For it to work make sure you add the NFS inbound rule to the security group of EFS with destination as EC2 security group.

ENI vs ENA vs EFA

- ENI : Elastic Network Interface - essentially a virtual network card. - ENA(EN) : Enhanced Networking. Uses single root I/O virtualization(SR-IOV) to provide high performance networking capabilities on supported instance types. - EFA : Elastic Fabric Adapter - A network device that you can attach to your Amazon EC2 instance to accelerate High Performance Computing(HPC) and Machine Learning applications.

Exam Tips

- ENI : For basic networking. Perhaps you need a separate management network to your production network or a separate logging network and you need to do this at low cost. In this scenario use multiple ENIs for each newtork. - EN : For when you need speeds between 10 Gbps to 100 Gbps. Anywhere you need reliable, high throughput. - EFA : For when you need to accelerate High Performance Computing(HPC) and ML applications or if you need to do an OS-bypass. If you see a scenario question mentioning HPC or ML and asking what network adapter you want, choose EFA.

WAF Protection

- Extra protection against web attacks using conditions you specify. You can define conditions by using characteristics of web requests such as : 1. IP addresses that requests originate from. 2. Country that requests originate from. 3. Values in requests headers. 4. Strings that appear in requests, either specific strings or string that match regular expression(regex) patterns. 5. Length of requests. 6. Presence of SQL code that is likely to be malicious(know as SQL injection). 7. Presence of a script that is likely to be malicious(know as cross-site scripting).

Exam Tips

- If the Spot Instance is terminated by Amazon EC2, you will not be charged for a partial hour of usage. However, if you terminate the instance yourself, you will be charged for any hour in which the instance ran. - Asymmetric encryption you have two keys public and private. - Symmetric encryption only one key. - Termination Protection is turned off by default, you must turn it on. - On an EBS-backed instance, the default action is for the root EBS volume to be deleted when the instance is terminated. But any additional volumes by default won't be deleted. - EBS root volumes of your default AMI's CAN be encrypted. You can also use a third party tool(such as bit locker) to encrypt the root volume, or this can be done when creating AMI's in the AWS console or using the API. - Additional volumes can be encrypted. - In EC2 the EBS root volume can only be ssd( general purpose or IOPS) and Magnetic.

Exam Tips

- In exam you will be given different scenarios and you will be asked how to block malicious IP addresses : 1. Use AWS WAF 2. Use Network ACLs

Exam Tips

- Instance storage is sometimes called as ephermal storage because once stoped you lose the data.Instance Store backed instances cannot be stopped. If the underlying hosts fails, you will lose your data. - EBS Backed Instances can be stopped. You will not lose data on this instance if it is stopped. - You can reboot both, you will not lose your data. - By default, both ROOT volumes will be deleted on termination. However, with EBS Volumes, you can tell AWS to keep the root device volume.

ENA

- It Uses single root I/O virtualization(SR-IOV) to provide high performance networking capabilities on supported instance types. SR-IOV is a method of device virtualization that provides higher I/O performance and lower CPU utilization when compared to traditional virtualized network interfaces. - Enhanced Networking provides higher bandwidth, higher packet per second(PPS) performance, and consistently lower inter-instance latencies. There is no additional charge for using enhanced networking. - Use where you want good network performance.

Amazon FSx for Lustre

- It is a fully managed file system that is optimized for compute-intensive workloads, such as high-performance computing, ML, media data processing workflows, and electronic design automation(EDA). - With Amazon FSx you can launch and run a Lustre file system that can process massive data sets at up to hundreds of gigabytes per second of throughput, millions of IOPS, and sub-millisecond latencies.

Spread Placement Group

- It is a group of instances that are each placed on distinct underlying hardware. - It is recommended for applications that have a small number of critical instances that should be kept separate from each other. - THINK INDIVIDUAL INSTANCES.

EC2 Placement Groups

- Just a way of placing your EC2 instances. Three different types of placement groups : 1. Clustered Placement Group : Low Network latency and High Network Throughput. 2. Spread Placement Group : Individual critical EC2 Instances. 3. Partitioned Placement Group : Multiple EC2 instances HDFS, HBase and Cassandra.

Lustre FSx vs EFS

- Lustre FSx : 1. Designed specifically for fast processing of workloads such as ML, high performance computing(HFC), video processing, financial modeling, and electronic design automation. 2. Lets you launch and run a file system that provides sub-millisecond access to your data and allows you to read and write data at speeds of up to hundreds of gigabytes per second of throughput and millions of IOPS. - EFS : 1. A managed NAS filer for EC2 instances based on Network File System(NFS) version 4. 2. One of the first network file sharing protocols native to Unix and Linux.

Can I move a reserved instance from one region to another?

- No - Depending on you type of RL you can You can modify the AZ, scope, network platform, or instance size (within the same instance type), but not Region. In some circumstances you can sell RIs, but only if you have a US bank account.

EC2 Model Use Cases

- On Demand : 1. Users that want the low cost and flexibility of Amazon EC2 without any up-front payment or long-term commitment. 2. Applications with short term, spiky or unpredictable workloads that cannot be interrupted. 3. Applications being developed or tested on Amazon EC2 for the first time. - Reserved Pricing : 1. Applications with steady state or predictable usage. 2. Applications that require reserved capacity. 3. Users able to make upfront payments to reduce their total computing costs even further. 4. Reserved Pricing Types : a. Standard Reserved Instances : These offer up to 75% off on demand instances. The more you pay up front and the longer the contract, the greater the discount. b. Convertible Reserved Instances : These offer up to 54% off on demand capability to change the attributes of the RI as long as the exchange results in the creation of Reserved Instances of equal or greater value. c. Scheduled Reserved Instances : These are available to launch within the time windows you reserve. This option allows you to match your capacity reservation to a predictable recurring schedule that only requires a fraction of a day, week, or a month.

EC2 Pricing Models

- On Demand : Allows you to pay a fixed rate by the hour(or by the second) with no commitment. - Reserved : Provides you with a capacity reservation, and offer a significant discount on the hourly charge for an instance. Contract Terms are 1 Year or 3 Year terms. - Spot : Enables you to bid whatever price you want for instance capacity, providing for even greater savings if your applications have flexible start and end times. - Dedicated Hosts : Physical EC2 server dedicated for your use. Dedicated Hosts can help you reduce costs by allowing you to use your existing server-bound software licenses.

HPC on AWS : Orchestration and automation

- Orchestration and Automation services that allow us to achieve HPC on AWS : 1. AWS Batch : a. AWS Batch enables developers, scientists, and engineers to easily and efficiently run hundreds of thousands of batch computing jobs on AWS. b. AWS batch supports multi-node parallel jobs, which allows you to run a single job that spans multiple EC2 Instances. c. You can easily schedule jobs and launch EC2 instances according to your needs. 2. AWS ParallelCluster : a. Open-source cluster management tool that makes it easy for you to deploy and manage HPC clusters on AWS. b. ParallelCluster uses a simple text file to model and provision all the resources needed for your HPC applications in an automated and secure manner. c. Automate creation of VPC, subnet, cluster type, and instance types.

IAM Roles with EC2

- Roles are more secure than storing your access key and secret access key on individual EC2 instances. - Roles are easier to manage. - Roles can be assigned to an EC2 instance after it is created using both the console and command line. - Roles are universal - you can use them in any region.

Encrypted Root Device Volumes and Snapshots

- Snapshots of encrypted volumes are encrypted automatically. - Volumes restored from encrypted snapshots are encrypted automatically. - You can share snapshots, but only if they are unencrypted. - These snapshots can be shared with other AWS accounts or made public. - You can now encrypt root device volumes upon creation of the EC2 instance. - The process to make an unencrypted volume to encrypted is : 1. Create a snapshot of the unencrypted root device volume. 2. Create a copy of the snapshot and select the encrypt option. 3. Create an AMI from the encrypted snapshot. 4. Use that AMI to launch new encrypted instances.

Spot Instances Use Case

- Spot Instances are useful for the following tasks : 1. Big Data and Analytics. 2. Containerized Workloads. 3. CI/CD and testing. 4. Web Services. 5. Image and Media Rendering. 6. High-Performance Computing. - Spot Instances is not good for : 1. Persistent Workloads. 2. Critical Jobs. 3. Databases.

EC2 Model Use Cases Continued

- Spot Pricing : 1. Applications that have flexible start and end times. 2. Applications that are only feasible at very low compute prices. 3. Users with urgent computing needs for large amounts of additional capacity. - Dedicated Hosts : 1. Useful for regulatory requirements that may not support multi-tenant virtualization. 2. Great for licensing which does not support multi-tenancy or cloud deployments. 3. Can be purchased On-Demand(hourly) 4. Can be purchased as a reservation for up to 70% of the on-demand price.

Spread Placement Groups

- Spread placement groups have a specific limitation that you can only have a maximum of 7 running instances per Availability Zone and therefore this is the only correct option. Deploying instances in a single Availability Zone is unique to Cluster Placement Groups only and therefore is not correct. The last two remaining options are common to all placement group types and so are not specific to Spread Placement Groups.

HPC on AWS : Storage

- The Storage services that allow us to achieve HPC on AWS : 1. Instance-attached storage : a. EBS : Scales up to 64,000 IOPS with provisioned IOPS(PIOPS). b. Instance Store : Scale to millions of IOPS; low latency. 2. Network Storage : a. S3 : Distributed object-based storage; not a file system. b. EFS : Scales IOPS based on total size, or use Provisioned IOPS. c. Amazon FSx for Lustre : HPS-optimized distributed file system; millions of IOPS, which is also backed by S3.

Exam Tips

- Volumes exist on EBS. Think of EBS as a virtual hard disk. - Snapshots exist on S3. Think of snapshots as a photograph of the disk. - Snapshots are point in time copies of Volumes. - Snapshots are incremental - this means that only the blocks that have changed since your last snapshot are moved to S3. - To create a snapshot for Amazon EBS Volumes that serve as root devices, you should stop the instance before taking the snapshot. - However you can take a snap while the instance is running. - You can create AMI's from snapshots. - You can change EBS volume sizes on the fly, including changing the size and storage type. - Volumes will ALWAYS be in the same Availability Zone as the EC2 instance. - To move an EC2 Volume from on AZ to another, take a snapshot of it, create an AMI from the snapshot and then use the AMI to launch the EC2 instance in a new AZ. - To move an EC2 volume form one region to another, take a snapshot of it, create an AMI from the snapshot and then copy the AMI from one region to the other. Then use the copied AMI to launch the new EC2 instance in the new region.

EC2 Hibernate

- We can stop and terminate EC2 Instances. If we stop the instance, the data is kept on the disk(with EBS) and will remain on the disk until the EC2 instance is started. - If the instance is terminated, then by default the root device volume will also be terminated. - When we start the EC2 instance, the following happens : 1. OS boots up. 2. User Data script is run(bootstrap scripts) 3. Applications start(can take some time). - When you hibernate an EC2 instance, the OS is told to perform hibernation(suspend-to-disk). Hibernation saves the contents from the instance memory(RAM) to your EBS root volume. We persist the instance's Amazon EBS root volume and any attached Amazon EBS data volumes.

HPC on AWS : Data Transfer

- What are some ways we can get our data into AWS? : 1. Snowball, Snowmobile(terabytes/petabytes worth of data). 2. AWS Data Sync to store on S3, EFS, FSx for Windows, etc... 3. Direct Connect.

Exam Tips

- When asked what to choose : 1. EFS : When you need, distributed, highly resilient storage for Linux Instances and Linux based applications. 2. Amazon FSx for Windows : When you need centralised storage for Windows-based applications such as Sharepoint, Microsoft SQL srever, Workspaces, IIS Web Server, SMB storage or any other native microsoft application. 3. Amazon FSx for Lustre : When you need high speed, high-capacity distributed storage. This will be for applications that do high performance computing(HPC), Financial Modelling, Big Data etc. Remember that FSx for Lustre can store data directly on S3.

Partitioned Placement Group

- When using partitioned placement groups, amazon EC2 divides each group into logical segments called partitions. Amazon EC2 ensures that each partition within a placement group has its own set of racks. Each rack has its own network and power source. No two partitions within a placement group share the same racks, allowing you to isolate the impact of hardware failure within your application. - THINK MULTIPLE INSTANCES. - Difference b/w spread and partition placement group is that you can have multiple instances in a partition placement group, where as single instance in a spread placement group.

Starting your EC2 Instance with EC2 Hibernate

- When you start your instance out of hibernation : 1. The Amazon EBS root volume is restored to its previous state. 2. The RAM contents are reloaded. 3. The processes that were previously running on the instance are resumed. 4. Previously attached data volumes are reattached and the instance retains its instance id. - With EC2 Hibernate, the instance boots much faster. The OS does not need to reboot because the in-memory state(RAM) is preserved. This is useful for : 1. Long-running processes. 2. Services that take time to initialize. - To hibernate the root EBS volume must be encrypted.

Windows FSx vs EFS

- Windows FSx : 1. A managed windows server that runs windows server message block(SMB) - based file services. 2. Designed for windows and windows applications. 3. Supports AD users, access control lists, groups and security policies, along with Distributed File System(DFS) namespaces and replication. - EFS : 1. A managed NAS filer for EC2 instances based on Network File System(NFS) version 4. 2. One of the first network file sharing protocols native to Unix and Linux.

If an Amazon EBS volume is an additional partition (not the root volume), can I detach it without stopping the instance?

- Yes, although it may take some time.

Can you attach an EBS volume to more than one EC2 instance at the same time?

- Yes, as of Feb 2020 certain typws of EBS volumes can be attached to more than one instance. - https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-volumes.html

HPC on AWS

- You can create a large number of resources in almost no time. You only pay for the resources you use - and, once finished, you can destroy the resources. - HPC is used for industries such as genomics, finance and financial risk modeling, ML, weather prediction, and even autonomous driving.

AMI Types (EBS vs Instance Store)

- You can select your AMI based on : 1. Region (regions and AZ) 2. OS 3. Architecture (32 bit or 64 bit) 4. Launch Permissions 5. Storage for the Root Device (Root Device Volume) : a. Instance Store(EPHERMAL STORAGE) b. EBS Backed Volumes

Spot Blocks

- You may also use a Spot Block to stop your Stop Instances from being terminated even if the Spot Price goes over your max Spot Price. You can set Spot Blocks for between One to Six hours currently.

You have developed a new web application in the US-West-2 Region that requires six Amazon Elastic Compute Cloud (EC2) instances to be running at all times. US-West-2 comprises three Availability Zones (us-west-2a, us-west-2b, and us-west-2c). You need 100 percent fault tolerance: should any single Availability Zone in us-west-2 become unavailable, the application must continue to run. How would you make sure 6 servers are ALWAYS available? NOTE: each answer has 2 possible deployment configurations. Select the answer that gives TWO satisfactory solutions to this scenario.

- You need to work through each case to find which will provide you with the required number of running instances even if one AZ is lost. Hint: always assume that the AZ you lose is the one with the most instances. Remember that the client has stipulated that they MUST have 100% fault tolerance.

Spot Fleet Startegies

- capacityOptimized : The spot instances come from the pool with optimal capacity for the number of instances launching. - lowestPrice : The spot instances come from the pool with the lowest price. This is the default startegy. - diversified : The spot instances are distributed across all pools. - InstancePoolsToUseCount : The spot instances are distributed across the number of spot instance pools you specify. This parameter is valid only when used in combination with lowestPrice.

Instance User and Meta Data

- curl http://169.254.169.254/latest/user-data/ : Contains bootstrap script. - curl http://169.254.169.254/latest/meta-data/ - Meta data is sued to get information about an instance(such as public ip).

CloudWatch: Host Level Metrics

CPU - CPU Utilization Network - N/W Utilization Disk - Disk Throughput(I/O) Status Check - Health Check of EC2 Instance or EC2 H/W

How to Terminate Spot Instances

See Video 4:30

EBS Use Case

Video 1:22 very important