How Ruby on rails works with Amazon RDS - mysql

I have a ruby on rails run on amazon ec2, database is mySQL.
Now I want to use Amazon RDS to backup this database in case the ec2 fails.
I read through the Amazon RDS user guide,it tells how to create a DB instance.
My question is:
1.what is the relation between created DB instance and my ec2 database?
2.When the DB instance "connect" to my ec2, what will happen?
The data used to send to ec2 mySQL server will be send to DB instance?
Is the database totally shifted to DB instance?So before I connect I should creare a same database in DB instance and tell ec2 send data to RDS ever since
3.If not,how the DB instance know the ec2 is down and takeover the data?
EDIT:
(Unsure)Is it that DB instance is just a place to put database.In order to use it,I need to set up database in DB instance,then connect to it by modifying database.yml file(this file tell rails server where the stored data goes).
How Is it possible to tell when the local database stops then at that time switch to DB instance?

There is absolutely no relationship between your EC2 MySQL DB and the RDS DB Instance. So what you are asking for is just not possible.
A better approach I would say is to have only RDS (No need to have MySQL running locally on EC2 instance). RDS takes snapshots regularly. Also, RDS is a managed service, so most of the MySQL administration tasks are handled by AWS and you don't have to worry. And you can rely on RDS snapshots from Backup perspective.

Related

Does AWS RDS support two way replication with local MySQL database?

I would like to sync the local MySQL database to Amazon RDS MySQL database. I found a solution for EC2 to RDS but not for Local Database to RDS.
I built a database including 12 tables which all I want to get backup them to cloud periodically or automatically.
I do not want to run EC2 server since I need only MySQL database to get backup on cloud.
I need a solution like Microsoft Database Sync Agent. Whenever changes detected in Local Database, it should be synced to the cloud database. How can I make this happen?
You could use the AWS Database Migration Service:
AWS Database Migration Service (AWS DMS) is a cloud service that makes it easy to migrate relational databases, data warehouses, NoSQL databases, and other types of data stores. You can use AWS DMS to migrate your data into the AWS Cloud, between on-premises instances (through an AWS Cloud setup), or between combinations of cloud and on-premises setups.
With AWS DMS, you can perform one-time migrations, and you can replicate ongoing changes to keep sources and targets in sync.
You can achieve this by following below steps.
Make a replica of local server to RDS.
Enable Query logging in local Database
Create a cron job which will process logging queries and it will execute queries on RDS instance in same order.
To generate a replica to RDS you can follow below steps.
You can't replicate your local database to RDS directly. Your need to dump you data and then after you can import it on RDS.
Instead of generating a dump file you can directly import data into RDS using below command.
mysqldump db_name | mysql -h 'other_hostname' db_name
You can find our more about this over here.
https://dev.mysql.com/doc/refman/5.7/en/copying-databases.html
Also first import tables & it's data then after import your triggers, routines & events. If you import together then there is a chances to get conflict and you job will be terminated.

How to sync local MySQL database to Amazon RDS database?

I am setting up a connection between MySQL Workbench and Amazon AWS RDS MySQL database. How can I sync the two databases?
The operation (Inserting, deleting and updating) directly happens to cloud (AWS RDS) database instead of storing first on the local database which is further sync to cloud. Because it is taking much time in storing procedure directly to the cloud.
I expect all operations happen first in a local database which then syncs to the cloud database.
You may be interested in using the AWS Database Migration Service, which should be able to meet all of your requirements including remote replication of your local database. (https://aws.amazon.com/dms/)

AWS RDS vs MySql database directly on EC2

I created MySql database directly on EC2 instance (I host there my web app and database), I didn't set up RDS. But my database constantly keep crashing. So now I want to use RDS.
How to integrate my existing databases on EC2 with RDS?
By integrate I mean simply how to migrate them to RDS that they stop crashing on EC2 instance. Do I have to remove them from EC2, stop mysqld service on EC2 and then create them from scratch on RDS and change database access configurations in my apps or is there simpler way?
Unload your data from the SQL instance into CSVs. Put it into S3. Terminate your EC2 instance. Spin up RDS instance. Load data out of S3 into RDS. Job done.

How to Synchronize MySQL Database from an On Premise to Amazon RDS

I am new to Amazon RDS, and looking to get answer for my question below and couldn't find the answer on stackoverflow yet.
I have a MySQL Database on premise that I want to synchronize with the MySQL Database on Amazon RDS. I understand that replication is possible with Amazon RDS, but how about continuous synchronization? Say my existing local database has one transaction that has been made, I want to synchronize just that transaction, either immediately or by schedule, so that I don't need to replicate the whole thing to RDS.
Does RDS have this feature for MySQL or any other database?
If not, what tools should I be using? EC2 + ? ?
Or is there any database that supports this so I can just run the database on EC2?
Your best (first) option should probably be the AWS Database Migration Service. This is a migration service for exactly your use-case.
If uptime is less of an issue, you could always do a mysql_dump, move that to an EC2 instance and load that into an RDS instance.

How does one see what data is stored in the RDS database?

Running our app on Amazon RDS. How does one review / inspect data in the database? For example, how can I get a list of articles?
My app is running on Ruby on Rails and on Heroku. One method I thought of, is by running the Heroku console command.
Is there a better way to see what data is stored in the RDS database?
I use MySQL Workbench to view data, run queries, and so on. It connects right up to the Amazon RDS MySQL instance using the regular MySQL settings.
Updated:
Be sure to add the ip address of the computer for which you're connecting to the RDS instance to the access list in RDS. IIRC, by default RDS instances will only accept connections from within AWS.
I was using SequelPro but they don't support ssl. Amazon RDS says something to the effect of having to use SSH to connect your EC2 to your RDS.
This is essentially what was done in the following tutorial which uses MySQL Workbench: http://thoughtsandideas.wordpress.com/2012/05/17/monitoring-and-managing-amazon-rds-databases-using-mysql-workbench/
I had also been using SequelPro before but this tutorial is very clear and I was up and running on MySQL Workbench in just a few minutes.