How different is the Amazons RDS DB Instance different from The normal EC2 Instance other than the fact that RDS DB Instance has a Database server running on it?
When an EC2 Instance goes down all the data associated with it also vanishes(when you dont attach an EBS). Is this true for RDS DB Instance as well?
I have already set up my database server with the following: 1 small Instance?(m1.small) with Mysql and attached a 10GB EBS and routed the Mysql Data Directories to EBS.
Is the small Instance of EC2 RDS any Different from the above?
An RDS db instance can be configured to not lose any data during downtime, either planned or unplanned. For unplanned downtime, AWS keeps transaction logs which are replayed automatically on a failover instance. These logs can also be used to get an instance to a specific point in time.
For planned downtime, you create a DB snapshot prior to stopping the instance, and can later start a new instance with the saved snapshot.
RDS is a unmanaged MySQL service, means you only start and load data into it and your ready to go.
Is the small Instance of EC2 RDS any Different from the above?
The small instance of RDS is a 64bit, which support multi AZ failover and pricing obviously is a little expensive compared to EC2 MySQL.
EC2 Mysql needs more administration, but you can setup it up to do replication and you can customize it to have better performance compared to RDS.
See also http://www.dotdeb.org/2010/05/04/mysql-on-amazon-benchmarks-rds-vs-ec2/
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We are currently setting up AWS hosting for our Web Application.
This Laravel Web Application will have a Schema per company that registers, meaning it will have a large sized mySql server.
I have gone through the motions of setting up a VPC with EC2 instances and and RDS for this mySql server.
However we are currently looking at using Laravel Forge as a tool to host.
What Forge does differently is that it includes the mySql Server on the EC2 instance not on an RDS.
The question I have come to ask here is, what are the implications if any of having the mySql server on the EC2 instance rather then an RDS.
Would there be performance issues?
Is it better practice to have an RDS?
Or is Forges out the box way of packaging this all together on an EC2 server fine?
By running this on an EC2 instance you will taking more of the responsibility of managing the database, not just installation but also patching, backups, recovery. Harder to maintain functionality such as replication and HA will also be on you to implement and monitor.
By running on RDS AWS is going to take the heavy lifting of this and implement a best practice version of MySQL which offers the flexibility of allowing you to run a MySQL stack in the cloud without having to really think about the implementation details under the hood other than deciding do you want it to be HA and how many replicas do you want.
In saying this by using RDS you're also giving up the ability to run it however you want, you are limited to the versions of the database that RDS supports (although this is now quite soon after release). In addition not all plugins or extensions will be active so check this functionality before deciding.
We're planning to move our Tomcat/MySQL app onto the Amazon cloud employing 2 EC2 instances (inst_1 & inst_2) running in different availability zones whereby inst_1 will contain the master RDS db and inst_2 the slave RDS db.
If we employ elastic load balancing to balance traffic between the two instances, will traffic directed to inst_2 that includes insert/update/delete db transactions first update the master RDS db in inst_1 followed by a synchronous update of the slave in inst_2; thereby ensuring that the two RDS instances are always synchronized?
Amazon's published info (whitepapers) suggests such, but doesn't explicitly state it. If not, how does one ensure that the two RDS instances remain synchronized?
Additional note: We're planning to employ Amazon's Elastic Beanstalk. Thanks!
You have to take a few things into consideration
AWS RDS instances are simple managed EC2 instances which run a MySQL server.
If you add a slave ( I think Amazon calls them read-replica) this is a read-only slave
Amazon doesn't manage the distribution of writing queries to the master server automatically.
Replication will ensure that your read slave always is up-to-date automatically ( with minimal delay which is increasing with write-load on the master )
This behavior is MySQL-specific
This means that you have to delegate manipulating queries to the master exclusively.
This can either be done by your application or by a MySQL proxy running on a extra machine.
The proxy then is the only interface your application servers will talk to. It is able to manage balancing between your RDS instances and the direction of any manipulation query to the master instance.
When RDS is used in multi-az mode you have no access to the secondary instance. There is only ever one instance that is visible to you, so most if your question doesn't apply. In case of failover the DNS address you are given will start resolving to a different ip. Amazon doesn't disclose how the two instances are kept in sync.
If instead of using a multi-az instance you use a single-az instance + a replica then it is up to you to direct queries appropriately - any attempt to alter data on the replica will fail. Since this is just standard MySQL replication, the replica can lag behind the master (in particular with current versions of MySQL the replica only runs a single thread)
I have an RDS MySQL persistant instance, and I am trying to run spot instances which are created once every 8 hours and then destroyed.
The issue I am having is that I don't understand how can I add those spot instances which have dynamic IPs to the security group of my RDS Instance in order to let them perform queries,etc.
Should I grab the IP as soon as the spot instance is created and the add it to the security group of the RDS instance each time a new spot instances is created? Also destroy it every time the spot instance is terminated?
Any tip on what approach to take will be much appreciated!
Thanks!
Assuming that both your spot instances and RDS are in the same region: when setting up an RDS security group, you can also allow machines in EC2 security groups to connect to your RDS machine. Simply add all your spot instances to a EC2 security group and grant access to RDS for this security group.
If your RDS and spot instances are in different regions, you could use the AWS API or an AWS API client like boto for Python to add the IPs automatically.
I have a large set of data to be analyzed and I am planning to use Amazon EC2 to compute. So I am wondering where can I store the data for computing.
There is a lot of lingo in the amazon world.
You can either store the data on an EBS drive connected to your EC2 instance, or if it is in MySQL format or a simple format, you could consider storing it on Amazon's managed MySQL service called RDS.
EC2 units can either be backed by S3 storage, or EBS volumes. If you want to have rapid access to your data, you will need to choose an EC2 instance backed by Amazon Elastic Block Storage (EBS). EBS gives you the flexibility to use any database or data structure you want.
Reading about and using the Amazon Web Services, I'm not really able to grasp how to use it correctly. Sorry about the long question:
I have a EC2 instance which mostly does the work of a web server (apache for file sharing and Tomcat with Play Framework for the web app). As it's a web server, the instance is running 24/7.
It just came to my attention that the data on the EC2 instance is non persistent. This means I lose my database and files if it's stopped. But I guess it also means my server settings and installed applications are lost as they are just files in the same way as the other data.
This means that I will either have to rewrite the whole app to use amazon CloudDB or write some code which stores the db on S3 and make my own AMI with the correct applications installed and configured. Or can this be quick-fixed by using EBS somehow?
My question is 1. is my understanding of aws is correct? and 2. is it's worth it? It could be a possibility to just set up a regular dedicated server where everything is persistent, as you would expect. Would love to have the scaleability of aws though..
If you use an EBS volume with your EC2 instance, you can mount/dismount them to have persistent storage. You can also use Amazon RDS to handle your database too which is handy (but can be slightly on the pricier side.)
So a way to think of it is:
Your EC2 instance: Get the OS set up exactly like you'd like it along with your web application - basically, get your static stuff all in place.
EBS volume: That can be mounted and can be used for things like user uploads.
RDS instance: This is a dedicated database server with no hassles. It's nice - I use a MySQL RDS and it automatically makes two daily backups, and is scalable like EC2 instances.
Amazon Web Service is a better approach at hosting your applications Jon. You have a basic understand of AWS but you need to know that you can also launch an instance that is persistent. Just launch an instance of a persistence AMI. Also you can install you database,webs server on the instance like a regular server. There is probably just minimal differences from running an Ec2 instance and a dedicated server. If you have any other questions you can contact me.