Migrating from AWS RDS to an AWS EC2 running MySQL - amazon-web-services

Yes, fellow SOrs, I'm doing it backwards. I tried an AWS RDS but the CPU seems to be spiking so often that I need the flexibility of an EC2 to run some fine tuning. I'm not a MySQL expert, so I'm asking:
How can I create a setup on the EC2 so that it reads and replicates my RDS?
Ideally I'd do the switch in real time via DNS but first I need the EC2 to act like a clone of the RDS updating with any new data happening between now and the actual migration period.
Any pointers are much appreciated. Thanks!

Why can't you use mysql-tuner with RDS?
You shouldn't need to run sysbench, since Amazon handles OS level tuning for you on RDS
Aurora is a drop-in replacement for MySQL and will scale better than any MySQL cluster you could setup on EC2
You should be addressing why your Wordpress instance is hammering the database so much instead of trying to optimize the database.
You should put a CDN in front of your Wordpress site and cache as much as you can to reduce the load on both your web server and database server. It looks like there are also solutions out there for using Redis to cache data so that Wordpress doesn't have to constantly go back to MySQL for data.
Amazon provides the CloudFront CDN, but I would also recommend looking into CloudFlare.
Honestly, given your number of concurrent users, unless you have tons of dynamic constantly changing content, you should be able to run your entire site on a t2.micro with CloudFlare in front of it with cache everything enabled.

I'd like to offer an update:
Mark B's input has been extremely valuable as I have discovered that I can run mysql tuner remotely and touch the RDS. Therefore there was no need to migrate after all.
The RDS CPU spikes were due to a large amount of non-INDEX JOINs.
I have added indexes and the results are fantastic:

Related

Optimizing latency between application server (EC2) and RDS

here's how the story goes.
We started transforming a monolith, single-machine, e-commerce application (Apache/PHP) to cloud infrastructure. Obviously, the application and the database (MySQL) were on the same machine.
We decided to move to AWS. And as the first step of transformation, we decided to split the database and application. Hosting application on a c4.xlarge machine. And hosting database to RDS Aurora MySQL on a db.r5.large machine, with default options.
This setup performed well. Especially the database performance went up high.
Unfortunately, when the traffic spiked up, we started experiencing long response times. Looked like RDS, although being really fast for executing queries, wasn't returning results fast enough over the network to the EC2 machine.
So that was our conclusion after an in-depth analysis of the setup including Apache/MySQL/PHP tuning parameters. The delayed response time was definitely due to the network latency between EC2 and RDS/Aurora machine, both machines being in the same region.
Before adding additional resources (ex: ElastiCache etc) we'd first like to look into any default configuration we can play around with to solve this problem.
What do you think we missed there?
One of the bigest strength with the cloud is the scalability and you should always design your application to utilise it and it sounds like your RDS instance is getting chocked due to nr of request more than the process time for the queries. So rather go more small instances with load balancing than one big doing all the job. And with Load Balancers you will get away from a singel point of failure due to you can have replicas of your database and they can even be placed in different AZ.
Here is a blogpost you can read on the topic:
https://aws.amazon.com/blogs/database/scaling-your-amazon-rds-instance-vertically-and-horizontally/
Good luck in your aws journey.
The Best answer to your question is using read replicas, but remember only your read requests could be sent to your read replicas so you would need to design your application that way
Also for some cost savings, you should try aurora serverless
One more option is passing traffic between ec2 and rds through a private network rather than using the public internet to connect your ec2 to rds that can be one of the mistakes that might be happening

Why should I use AWS RDS/DynamoDB instead of putting everything inside an EC2?

Currently I'm hosting my IPB forums on a single high-end OVH dedicated server without any tech issues. I'm considering moving to AWS and AWS recommends (??) you to host your web app on a EC2 (or ELB if you want scalability) and host your database separately on RDS/DynamoDB (RDS on my use case).
I have almost 5k CCU during peak hours and 50GB+ database.
Why should I use AWS RDS/DynamoDB instead of putting everything inside an EC2? Isn't that more expansive?
You can put it all on Ec2 (not dynamodb, there is no production version that you can run local), but a db like mysql or anything else that can be installed on the instance - then you are responsible for backing it up, apply patches etc.
I for years ran web apps on ec2 using a local SQL Server database, and they worked just fine.
However, once I moved my databases to RDS I slept a lot better. I no longer need to worry about an instance crashing in the middle of the night and losing customer data - I pay AWS to worry about it for me.
So, yes, technically it's possible - and it will even work - until something goes very wrong. If you are fanatical about doing your backups, storing them somewhere safe, and applying all required patches - you may be fine; I'd rather pay AWS, but it will absolutely work and you can always upgrade later.

Major differences of AWS and normal VPS (server)

I have a very basic idea on servers. So far I have only worked with few Ubuntu VPS server which I can easily maintain, install a database, upload my code and run my projects. And to save static data like image/video I use local SSD storage of my server.
Now I got some projects where AWS is required to use. In the beginning, I thought it would be very similar to my normal Ubuntu based VPS server. But while I start researching/reading articles also their own docs I find out it has lots more cool features for server and at the same, it's little complicated for a beginner. I would be really glad if someone give his time and reply on these questions of mine to clear concept about AWS of mine and people like me
As my plan is to use one EC2 instance to run my project. But I can see many experts suggest to use Elastic Beanstalk and create EC2 instance inside that. While I can directly run my project with EC2 without taking help from Elastic Beanstalk. So why it's better / what other help do it(Elastic Beanstalk) provide?
When I am checking the pricing of EC2(On-demand > Linux Unix) it says ECU as Variable. What does that mean? And where does ECU work
Instance Storage (GB) as EBS only. Does that mean I can't have any storage with my server I must buy separately? But in my previous VPS server, I use to get fewer storages with my server. Because storage is required if I want to install new software like MySQL/Redis/Python each of them requires local storage. Also if I want to upload my code or few static images it requires storage.
Like storage do I also need to buy other instances for a database? Like if I want to use PostgreSQL as my database do I need to buy AWS RDS or I can install that inside my Linux system?
Lastly, what are the main differences of my normal VPS Linux server and in AWS EC2 Linux server?
Thanks in advance for giving time :)
Let me try to answer your questions inline.
As my plan is to use one EC2 instance to run my project. But I can
see many experts suggest to use Elastic Beanstalk and create EC2
instance inside that. While I can directly run my project with EC2
without taking help from Elastic Beanstalk. So why it's better /
what other help do it(Elastic Beanstalk) provide?
If you are planning to use a single server and a database going with EC2 and RDS would be straightforward. However, if you are planning to set up, autoscaling (automatically increasing the number of servers only when load increases and return back to one server), load balancing and DevOps support, you need to set them up which requires more knowledge on AWS platform. AWS Elastic Beanstalk does these for you automatically, also by giving you the options to select the technology of your application and simply upload the code.
When I am checking the pricing of EC2(On-demand > Linux Unix) it says ECU as Variable. What does that mean? And where does ECU work
ECU is simply a rough figure to compare the processing across multiple EC2 classes that are having the different levels processing power.
Instance Storage (GB) as EBS only. Does that mean I can't have any storage with my server I must buy separately? But in my previous VPS server, I use to get fewer storages with my server. Because storage is required if I want to install new software like MySQL/Redis/Python each of them requires local storage. Also if I want to upload my code or few static images it requires storage.
EBS storage is reliable storage (With internal redundancy) that will last beyond your instance lifetime. Which means, you can upgrade the EC2 class and install software, or store files, which will remain in the EBS volume unless you delete it.
Since you are basically paying for the GBs, you can also create another EBS volume for static files and mount it to the EC2 instance if you want.
Like storage do I also need to buy other instances for a database? Like if I want to use PostgreSQL as my database do I need to buy AWS RDS or I can install that inside my Linux system?
It's not mandatory but recommended since you can even use a smaller instance for a web server and use another one for the DB. It's up to you. For example, the cost would be roughly similar if you use two small EC2 instances for a web server and DB server (Or use RDS) or use a single medium-size EC2 instance where both DB and web is running.
Lastly what are the main differences of my normal VPS Linux server and in AWS EC2 Linux server?
You will get more options in terms of selecting the hardware underneath since AWS provides different configuration options. In addition, EC2 instances are able to utilize the AWS ecosystem for Networking, Security, Load balancing & etc for better-optimized solution architectures in terms of reliability, security, performance & etc.
Q1) Beanstalk is a management application. AWS has several: CloudFormation, OpsWorks. Third party vendors have their own: Chef, Ansible, Terraform, etc. I really like Beanstalk and how it makes deploying code very easy for small sites (one command). I can scale up or scale down with a button push. I also use CloudFormation every day for just about everything.
Q2) ECU is a AWS Equivalent Compute Unit used to compare one instance with another. How does that translate to physical CPUs? Don't know as AWS does not publish its absolute meaning. Use is only to compare EC2 instances.
Q3) When you launch an EC2 instance, you will need storage. This is an additional cost (around $0.10 per GB per month). You will specify the size and type of storage (there are a number of types). There is also Instance Store Volumes. Stay away from these unless you really understand how to use them (they don't persist a shutdown so all data is lost). There are good use cases for Instance Store (AI, Big Data, Image processing), but a website is not one of them.
Q4) If your EC2 instance is big enough (2 GB of memory and larger), you can install PostgreSQL, MySQL, etc on your EC2 instance. Otherwise AWS has a number of database optios: DynamoDB, RDS, Aurora, etc.
Q5) Difficult to answer as each vendor offers its own set of features. EC2 instances are virtual machines. You have control over the raw power of that VM. Most VPS servers have management interfaces that EC2 does not. Usually EC2 is more expensive than VPS servers.
Watch a couple of AWS videos on YouTube. This will help you to understand AWS and why it is so successful in the cloud. Linux Academy, A Cloud Guru, etc. have very good training courses on AWS.
AWS Essentials: EC2 Basics
If you have further questions, open a new StackOverflow question per question. You will seldom get answers to long multi-question questions.

AWS architecture help for running database dumps

I have mysql running on one ec2-instance and tableau uses this database. mysqldump runs from production servers every 4 hours during which the system is down for probably 10-15 mins due to the dump. I am planning to have another ec2 instance with mysql running and and elb on top of these two instances so that the system wont be down trough the dump. For this I might have to de-register the instances from elb during the dump and register them back after the dump. Is this the right way to do it in the situations like this?
You can't use an ELB with MySQL servers. The ELB wouldn't know which server was master and which was slave, so it wouldn't know which to send updates to.
Is there any reason you aren't using Amazon's RDS service for your database servers? It provides automated snapshots that don't cause any down-time. It also makes it easy to create a read-replica against which you could perform mysqldumps without affecting the main server.
Currently you are taking logical backups of your system every 4 hours. Logical backups in most cases should only be used in a worst case scenario. In the event of a restore, logical backups are very slow compared to alternatives, such as snapshots and binary backups. If snapshoting using Amazon RDS or any of the other multitude of alternatives out there in your environment is not an option, I would look into Xtrabackup. This is a free stand alone HOT online binary backup tool that can be used with a Vanilla install of MySQL. This should not bring down your production server, assuming you are using InnoDB and not an alternative storage engine such as MyISAM. I personally used it for hot online binary backups and to automate building slaves in my previous work environment. A binary backups bottleneck is your network speed in terms of the restore process and is exponentially faster than a logical backup.
If setting up another MySQL instance is your only option look into GTID replication and/or Master-Passive HA environment in order to take the mysqldump off of the secondary non-active production server so that your production environment does not go down.
The bottom line is that you should not be taking production down to do a logical backup every 4 hours. This is def not ideal in any production environment.
Have a look at Amazon Database Migration Service (https://aws.amazon.com/dms/). It allows you to do zero-downtime database migration or just synchronization.

Understanding Amazon offerings

I am working on a project and am at a point where the POC is done and now want to move towards a real product. I am trying to understand the Amazon cloud offerings just to see if I need to be aware of them at development time. I have a bunch of questions that I cannot get answered from the Amazon site. Its probably because I am new to the whole web services thing and have never hosted a site before. I am hoping someone out here will explain this to me like I am a C programmer :)
I see amazon has a bunch of offerings -
EC2
Elastic Block Store
Simple DB
AuotScaling
Elastic Load Balancing
I understand EC2 is virtual server instances that I can use and these could come pre-loaded with what I want (say Apache + python). I have the following questions -
If I want a custom instance of something (like say a custom apache module I wrote for my project). Can I create a server instance using the exact modules and make it the default the next time I create a new instance or in Autoscaling?
Do I get an IP Address to access this? Can I set my own hostname to it? I mean do I get a DNS record? Or is it what Elastic IP is?
How do I access it from the outside? SSH? Remote Desktop? Or is it entirely up to how I configure the instance?
What do they mean by Inter-Region or Intra-Region data transfer? What is data transfer to begin with? Is it just people using my instance? So if I go live with it that will be the cost I have to pay for people using it?
What is the difference between AutoScaling and Elastic Load Balancing?
What is Elastic Block Store? Is it storage? If so do I have to worry about backups or do they take care of it?
About the Simple DB -
It looks like the interface to use this is different to my regular SQL calls. Am I correct?
If so the whole development needs to be tailored specifically for Amazon. Which kind of sucks. Is there a better alternative?
Do I get data backups or do I have to worry about it myself?
Will I be able to connect to the DB using regular tools to inspect the DB (during or afte development). Or do I get other tools made by Amazon for it?
What about security? The DB is obviously somewhere in the cloud farm away from the EC2 instance. My DB password is going over the wire and so is all my data totally unencrypted. Don't I have to worry about that? The question comes up only because I don't own any of the hardware.
I really hope some one points me in the right direction here.
Thanks for taking the time to read.
P
I just went through the question and here I tried to answer few of them,
1) AWS EC2 instances doesnt publish pre-configured instances, in fact its configured by the developers and made it publicly available to the users so that they can use it. One can any one of those instances or you can just opt for what ever OS you want which is raw and provision it accordingly and create a snap shot of it so that you can use it for autos caling.The snap shot becomes the base AMI in your case.
2) Every instance you boot will have a public DNS attach to it, you can use the public DNS to connect to that instance using ssh if your are a linux user or using putty if you are a windows users. Apart from that, you can also attach a elastic IP which comes with a cost will is like peanuts and attach it to the instance and access your instance through the elastic IP and you can either map the public DNS or elastic ip to map to a website by adding a A record or Cname respectively.
3)AWS owns databases in the different parts of the world. For example you deploy your application depending upon your customer base, if you target customers are based out of India, the nearest region available is Singapore which is called as ap-southeast-1 by AWS. Each region will have multiple availability zones, example ap-southeast-1a and ap-southeast-1b, which are two different databases and geographically part. Intre region means from ap-southeast-1a to ap-southeast-1b. Inter Region means, from ap-southeast-1 to us-east-1 which is Northern Virginia Data centre. AWS charges from in coming and out going bandwidth, trust me its nothing.
They chargge 1/8th of a cent per GB. Its a thing to even think about it.
4)Elastic Load balancer is cluster which divides the load equally to all your regions across availability zones (if you are running in multi AZ) ELB sits on top the AWS EC2 instances and monitors the instance health periodically and enables auto scaling
5) To help you understand what is autoscaling please go through this document http://aws.amazon.com/autoscaling/
6)Elastic Block store or EBS are like hard disk which is a persistent data storage which can be attached to your instance.Regarding back up yes dependents upon your use case. I do backups of EBS periodically.
7)Simple Db now renamed as dynamo DB is nosql DB, I hope you understand what is nosql db, its a non RDMS db systems. Please read some documentation to understand what is nosql db is.
8)If you have mysql or oracle db you can opt for RDS, please read the documents.
9)I personally feel you are newbie to the entire cloud eco system, you need to understand what exactly cloud does first.
10)You dont have to make large number of changes to development as such, just make sure it works fine in your local box, it can be deployed to cloud with out much ado.
11) You dont have to use any extra tool for that, change the database end point to RDS(if your use it) or else install mysql in your ec2 instance and connect to the local db which resides in the ec2 instance and connect to it,which is as simple as your development mode.
12)You dont have to worry about any security issues aws, it is secured. Dont follow the myths, I am have been using aws since 3 years running I dont even know remember how many applications, like(e-commerce,m-commerce,social media apps) I never faced any kind of security issues and also aws allows to set your security how ever you want.
Go ahead, happy coding. Contact me if you have any problem.
The answer above is a good summary on AWS. Just wanted to add
AWS offers full data center, so it depends what you are trying to achieve. For starters you will need,
EC2 - This is your server, it comes with instance storage, which will be lost on restart
EBS - Your mounted storage, the data is persisted across reboots
S3 - Provides storage (RESTful API's on top, the cost is usage based rather than "provisioned" as in EBS)
Databases - can start with Amazon RDS, which provides managed database services, you can chose between various available databases. You can also install your own database using EC2 + EBS, you will have to take care of managing the database yourself.
Elastic IP: Public facing IP address, you can point your DNS server to this.
One great tool to calculate the pricing,
http://calculator.s3.amazonaws.com/calc5.html
Some other services to take in account are:
VPC (Virtual Private Cloud). This is your own private network. You can define subnets, route tables and internet gateways there. I would strongly recommend to use VPC for any serious deployment of more than one instance.
Glacier - this will replace your tape library to storing backups.
Cloud Formation - great tool for deployment and automation of instances.