I have Amazon Aurora for MySQL t3.db.medium instances. I would like to scale down to t3.db.small.
If I modify the instance settings in AWS console, will my DB data be preserved? So can I scale down without service interruption? I think I should be able to do this, but I just wanna make sure. There is prod instance involved.
I have the same question about Elastic Cache (AWS redis). Can I scale that down without service interruption?
According to Docs, there is table(DB instance class) which tells which settings can be changed, you can change your instance class for your aurora, as a note An outage occurs during this change.
For redis
according to docs, you can scale down node type of your redis cluster (version 3.2 or newer). During scale down ElastiCache dynamically resizes your cluster while remaining online and serving requests.
In both the cases your data will be preserved.
Related
We need to know what are the best options to set AWS RDS instance (Aurora mysql) that is standalone and does not get traffic from actual RDS cluster.
Requirement is for our data team to write analytical queries but we do not want it to impact actual application and DB performance. Hence we need a DB which always has near to live data but live traffic or application does not connect to this instance.
Need to know which fits better, DL clone OR AWS Pilot light OR AWS Warn standby OR AWS hot standby OR
multi-AZ configuration.
Kindly let us know which one would fit our requirement better.
We have so far read about below 3 options,
AWS Amazon Aurora DB clone, https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/Aurora.Managing.Clone.html
AWS Pilot light or AWS Warn standby or AWS hot standby
. https://aws.amazon.com/blogs/architecture/disaster-recovery-dr-architecture-on-aws-part-iii-pilot- light-and-warm-standby/
With multi-AZ configuration, we can create a new instance in new AZ, so that his instance will have a different host (kind off, a fail over strategy), where traffic to his instance will be from our queries and not from live prod application, unless there is some fail over issue.
Option 1, Aurora cloning says
Run workload-intensive operations, such as exporting data or running analytical queries on the clone.
...which seems to be your use case here.
Just be aware that the clone will not see any changes to the original data after it is made. So you will need to periodically delete and re-clone to get the updated data
Regarding option 2, I wrote those blog posts, and I do not think that approach suits your use case. That approach is for disaster recovery
Option 3 may work. To modify it a bit, the concept here is to create an Aurora Replica, which as you say is a separate instance. The problem here is the reader endpoint for your production workload, it may hit that instance (which is not what you want)
EDIT: Adding new option 4
Option 4. Check out Amazon Aurora zero-ETL integration with Amazon Redshift. This zero-ETL integration also enables you to analyze data from multiple Aurora database clusters in an Amazon Redshift cluster.
I have an ubuntu server (ami-714ba518) which has a webserver on it (Apache and PHP). It is connected to a MySQL server on RDS. I want to setup auto scaling when load goes above 60-70% , but I'm having trouble getting my head around how it works.
My concern is that, when a change is made to a file in server, how does that change reflect on the other instances that auto scaling has started?
Regards!
Scaling http servers assumes that they are stateless, meaning that the state of them is dedicated to persistence layer - database, and not to servers themselves. If one of your instances writes something on its disk, this data won't be available to autoscaled new instances. Changes like this do not replicate by autoscaling feature. You can achieve that with shared file system via EFS, though, but it won't be replication. It'll be a shared resource.
P.S. Automatic EFS volumes attachment described here: https://docs.aws.amazon.com/efs/latest/ug/mount-fs-auto-mount-onreboot.html
The Autoscaling doesn't replicate the changes from your host server. If you already done the changes in your site, then may be you can create Custom AMI from your existing EC2 instance, and then use the same for launching new instances using autoscaling.
You need to use some common back-end service which will serve your changes to all of your web servers (existing or newly launched).
Take a look at s3 or efs.
Apologies if this isn't the right place to ask this question.
I'm looking to create an automated copy (backup) of my AWS RDS (MySQL) database daily and have this backup restored daily to another RDS instance and made available to another set of applications
I already have daily backups running and I can create a new rds instance from a backup but I want this to happen automatically within AWS.
Looking through AWS documentation and I can't find anything that fits this purpose but maybe there's a service that I'm not aware of.
AWS Aurora for MySQL and PostgreSQL support AutoScaling.
Autoscaling dynamically adjusts the number of Replicas available for cluster based on different metrics and policy. When sudden workload increase it'll add move read replicas and when it'll decrease it'll also remove so you don't have to pay for it.
Aurora AutoScaling
AWS RDS doesn't support autoscaling but you can always scale horizontally and vertically manually.
Scaling Your Amazon RDS Instance Vertically Horizontally
Last day I wanted, according to AWS recommendations, put my ec2 instance inside of an autoscaling group. I created my ec2 instance by using the standard linux AMI instance and then I installed a full LAMP server.
The next morning I tried accessing my apache and guess what? My LAMP wasn't there anymore! Everything was wiped away.
I guess this is because, for some reason, the autoscaling group deleted my instance and recreated it vanilla.
Now I still want to autoscale my instance but, of course, I want to keep my LAMP and the stored data.
So here's my questions:
How to create a customized image starting from my actual instance?
Would it be correct to create the mysql DB using AWS RDS so to not keep it linked to my instance?Is it more or less expensive than dedicating a EBS storage?
I also want to keep my /var/www/html data somewhere shared between instances: while it is true that, on production, I won't update those files often it is also true that I don't want to lose them just because the autoscaling resets my instance state. I also don't want to re-create an image each time I update said files... What's the best way?Maybe an s3 bucket? Or, still, an EBS storage shared between instances?
I would assume that the reason that your "LAMP [server] wasn't there anymore" was because the web server failed health checks and was terminated and replaced by AutoScaling.
Elastic Beanstalk would be a good way to manage some of the complexity here. If that's not an option then you should read up on AutoScaling, ALB, and health checks.
In response to your specific questions:
you can create an Amazon Machine Image (AMI) from an instance. When you, or AutoScaling, launch a new instance from that AMI, you can get the instance up to date by running a script in userdata
move the DB from the web/app server to RDS, or to a DB server that you manage yourself
maintain the html/js/css etc. in S3 and sync them to your web server periodically (there are other options, but that's simple)
How to scale horizontally amazon RDS instance? EC2 and load balancer+autoscaling is extremly easy to implement, but if I want scaling amazon RDS?
I can ugrade my RDS instance with more powerfull instance or I can create a read replica and I can direct SELECT queries to it. But in this mode I don't scale anything if I have a read-oriented web application. So, can I create RDS read replica with autoscaling and balance them with load balancer?
You can use a HAProxy to load-balance Amazon RDS Read Replica's. Check this http://harish11g.blogspot.ro/2013/08/Load-balancing-Amazon-RDS-MySQL-read-replica-slaves-using-HAProxy.html.
Hope this helps.
Note RDS covers several database engines- mysql, postgresql, Oracle, MSSQL.
Generally speaking, you can scale up (larger instance), use readonly databases, or shard. If you are using mysql, look at AWS Aurora. Think about using the database optimally- perhaps combining with memcached or Redis (both available under AWS Elasticache). Think about using a search engine (lucene, elasticsearch, cloudsearch).
Some general resources:
http://highscalability.com/
https://gigaom.com/2011/12/06/facebook-shares-some-secrets-on-making-mysql-scale/
If you are using PostgreSQL and have a workload that can be partitioned by a certain key and doesn't require complex transactions, then you could take a look at the pg_shard extension. pg_shard lets you create distributed tables that are sharded across multiple servers. Queries on the distributed table will be transparently routed to the right shard.
Even though RDS doesn't have the pg_shard extension installed, you can set up one or PostgreSQL servers on EC2 with the pg_shard extension and use RDS nodes as worker nodes. The pg_shard node only needs to store a tiny bit of metadata which can be backed up in one of the worker nodes, so they are relatively low maintenance and can be scaled out to accommodate higher query rates.
A guide with a link to a CloudFormation template to set everything up automatically is available at: https://www.citusdata.com/blog/14-marco/178-scaling-out-postgresql-on-amazon-rds-using-masterless-pg-shard