The Network Administrator Survival Kit

Amazon EC2 instances are monitored by Amazon CloudWatch by default. The default monitoring is called the Basic Monitoring. Basic Monitoring includes seven pre-selected metrics at five-minute frequency and three status check metrics at one-minute frequency for no additional charge. However, when you first launch an EC2 instance, you have the option of enabling detailed monitoring. Detailed Monitoring includes all the metrics available in Basic Monitoring but at one-minute frequency. Instances with Detailed Monitoring enabled allows data aggregation by Amazon EC2 AMI ID and instance type. Detailed Monitoring has an additional fee if selected. Once an EC2 instance has been launched, you can always toggle detailed monitoring on or off later. This is useful for troubleshooting. So the recommendation is to NOT turn detailed monitoring on initially. If autoscaling or elastic load balancing is being used, CloudWatch will also provide Amazon EC2 instance metrics aggregated by Auto...

Last week I booked in and did the SysOps Admin practise exam. Based on my working experience with AWS and some materials I read, I had scored 75%. Technically that's a pass. I would imagine the real test would be somewhat harder, but at least doing the practise exam gives you an idea of what your current strengths and weaknesses are. The results look like below : Overall Score: 75% Topic Level Scoring: Domain 1 - Monitoring and Metrics: 66% Domain 2 - High Availability: 100% Domain 3 - Analysis: 100% Domain 4 - Deployment & Provisioning: 75% Domain 5 - Data Management: 100% Domain 6 - Security : 66% Domain 7 - Networks: 33% With some more work over the next week, I will then book in for the real exam.

Elastic IP addresses are static Public IP addresses that are allocated to AWS Accounts.You can associate it to an EC2 instance or network interface. You need to manually allocate an Elastic IP address to your account. They are not automatically assigned. By default, you can allocate up to 5 Elastic IP addresses. To allocate more, you need to submit a request to AWS. An Elastic IP Address can easily be disassociated from an EC2 instance or network interface and re-associated with another instance or interface. However, if you were to release it from your account, it would go back to the pool of public IP addresses in AWS that can be assigned to other AWS accounts. There is no guarantee that if you were to allocate a new IP address to your account you would get the same one you had previously. BE CAREFUL and do not just release IP addresses because you are not using them. Disassociating from EC2 instances and network interfaces is fine to do as the Elastic IP addresses still remain in ...

AWS has many data centres around the world. Amazon has created AWS Regions in different countries and have setup data centres in these locations. There are usually two to three data centres grouped into a particular region. Each region is completely independent of each other and communicate via the Public Internet. A customer would choose to create their Amazon EC2 instances, for example, in a particular region that would be closest to where their clients will be accessing them. Each data centre in a region is called an Availability Zone and are physically isolated from each other. They are isolated enough that should a major catastrophy occur in the location where a particular data centre resides, the other data centres in that region would be unaffected. The only exception would be if a moon sized object hit that region. If that happens, it would just be bad luck. Each Availability Zone in a Region are linked via low-latency private network connections. This allows an infras...

Elastic Load Balancing is a service which allows for the automatic distribution of incoming traffic across multiple Amazon EC2 instances.These EC2 instances should be in separate availability zones in a particular region.This enables applications to achieve fault tolerance and high availability if they are designed so that they can be accessed from multiple server instances. Sometimes an application may not need to be designed as such if they both point to the same data source. More often than not, these applications can be run from anywhere. They are good candidates to be put behind the Elastic Load Balancing service.It is up to the system or cloud administrator to ensure that identical versions of the application exist across all servers that are going to be load balanced. The Elastic Load Balancing service can be integrated with Auto Scaling in AWS. As more load is put on your application servers, additional EC2 instances can be launched by Auto Scaling.Once the load dissipates. E...

Amazon Web Services provides the services and infrastructure to build highly available and fault tolerant environments in the cloud. However, like most clouds, you have to design your systems for fault tolerance and high availability by utilizing the services offered by AWS. Some AWS services have already been designed by Amazon to be highly available and fault tolerant. These include Amazon Simple Storage Service (S3), Amazon Simple DB, Amazon Simple Queue Service (SQS), and Amazon Elastic Load Balancing (ELB). Most companies who build their infrastucture in AWS will use Amazon Elastic Compute Cloud (EC2) and Amazon Elastic Block Store (EBS) for their virtual servers (EC2 instances), and disk storage for their servers (EBS volumes). These virtual servers live on physical hosts, and these EBS volumes live on physical disks. Physical hosts have power supplies, motherboards, and RAM which can and will die. Physical disks can and will fail. While AWS would have set up RAID for their...

AWS CloudFormation - Create a VPC Using AWS CloudFormation AWS CloudFormation allows you to treat Infrastructure as Code. Your infrastructure can be created through the use of scripting. I have written a tutorial on how to create a VPC using AWS CloudFormation. Here is the link to it : http://hubpages.com/_2482n6o6s3pqm/technology/Setup-an-AWS-Virtual-Private-Cloud-with-AWS-CloudFormation