Posts Tagged: Amazon
AWS lowers cloud pricing by launching the T2 instance type that can burst to handle occasional workload spike
T2 instances are Burstable Performance Instances that provide a baseline level of CPU performance with the ability to burst above the baseline. The baseline performance and ability to burst are governed by CPU Credits. Each T2 instance receives CPU Credits continuously at a set rate depending on the instance size. T2 instances accrue CPU Credits when they are idle, and use CPU credits when they are active. T2 instances are a good choice for workloads that don’t use the full CPU often or consistently, but occasionally need to burst (e.g. web servers, developer environments and small databases).
Powerful Redmine in AWS
In this post i will show how to make a installation of Redmine in AWS with some nice tools from AWS (EC2, RDS, S3, SES, ElastiCache) and making it auto scalable.
Amazon SES – Simple Email Service
Amazon Simple Email Service (Amazon SES) is a highly scalable and cost-effective bulk and transactional email-sending service for businesses and developers. Subscription is quick and is on pay-as-you-go basis. 
Delete ElasticBeanstalk bucket
If you can’t delete Elastic Beanstalk created bucket, first remove all files inside the bucket then remove de bucket policy.
Go to the bucket’s policy (bucket –> properties –> permissions –> edit bucket policy)
Save the change to the Bucket Policy.
Now right click on the bucket and press delete.
AWS t1.micro 100% CPU
Sometimes EC2 CloudWatch monitoring shows 100% CPU usage but when you ssh to your instance and try to see it with ‘top’ you can’t understand what is happening. Probably, Amazon is “borrowing” some of your CPU cycles to give to someone else who needs it – this is standard practice for a virtualised environment where physical server resources like RAM usage and CPU cycles are often hugely over-committed.
To check for CPU steal, run top and take a look for the %st value. If this value is anything other than zero, it means your VM’s CPU cycles are being “borrowed”.
More: Understanding CPU Steal Time
Recovering a Lost Amazon EC2 SSH Key
In case you lose your Amazon EC2 SSH Key, and can’t login in your instance. This isn’t a big problem if your instance is EBS based and you use an Elastic IP.
1. Upload your new SSH Key, or use one made by AWS
2. Make an AMI of your instance
3. Launch a new machine from your AMI, select the new SSH Key
4. Log in your machine with default user (ubuntu, ec2-user, depends on your original AMI image)
5. Change the Elastic IP to the new machine
6. Turn of the old machine and terminate it.
RDS Instance Sizes, maximum concurrent connections
RDS Class max_connections
t1.micro 34
m1.small 125
m1.medium 296
m1.large 623
m1.xlarge 1263
m2.xlarge 1441
m2.2xlarge 2900
m2.4xlarge 5816
How to waste less money with AWS
First of all, you need to carefully select the region where you are going to stablish your servers.
US-EAST / US-WEST-2 are the cheaper regions by the time that i wrote.
You can check the prices per regions on the links at the end of this post.
Using AWS for almost a year in free tier, i did not paid attention to purchasing options of instances.
How to survive with AWS EC2 T1.Micro instance
With my t1.micro, i can host my personal redmine, git and blog. But i couldn’t do that with default settings.
I have used swap on file to it and here is how you can do it:
Copy & paste the code below:
sudo su -c '
dd if=/dev/zero of=/var/swapfile bs=4096 count=524288
chown root:root /var/swapfile
chmod 0600 /var/swapfile
mkswap /var/swapfile
swapon /var/swapfile
echo "/var/swapfile none swap sw 0 0" >> /etc/fstab
'
To disable you can use:
sudo swapoff -v /var/swapfile
sudo rm /var/swapfile
sudo sed -i '/swapfile/d' /etc/fstab
Amazon Web Services – Free Tier
How to get started with AWS free?
Just go to http://aws.amazon.com/free/ and make your account.
Credicard will be needed even for a free account.
What can be done with the free account?
It’s up to you! If you are going to make a light traffic website free tier can handle it. 🙂
You can have up to two EC2 instances (1 Linux, 1 Windows) with 613M Ram and up to 30GB EBS Size. You can go with all your 30GB on a Linux instance it’s the best way to spend your ‘free’ resources. (Windows is memory hungry.)
You can have up to one RDS instance (postgres, mysql, …) with 20GB of DB storage and 20GB for backups.
You can have up to one S3 with 5GB of storage with up to 20k put and 20k get requests.
You can have up to one Memcached server with 213MB
And some more things (ELB, DynamoDB, SNS, CloudWatch, …)