Reputation: 1418
This question has a conceptual and practical parts.
Conceptually I'd like to know if using the autoscaling functionality is equivalent to simply increasing the compute power by a factor of the number of added instances?
Practically ... how does this work? I have one running instance, its database sitting on an LVM composed of multiple EBS volumes, similarly with all website data. Judging from the load on the instance I either need to upgrade to a more powerful instance or introduce this autoscaling. Is it a copy of the running server? If so, how is the database (etc) kept consistent?
I've read through the AWS documentation, and still haven't got the picture yet - I could set one autoscaling group up which would probably clear my doubts, but I am very leery to do this with a production server.
Any nudges in the right direction would be welcome.
Upvotes: 1
Views: 257
Reputation: 46841
Normally if you have a solution that also uses a database, and several machines in the solution, the database is typically not on any of the machines but is instead hosted seperately with each worker machine pointing to the same database - if you are on AWS platform already, then DynamoDB or RDS are both good solutions for this.
In theory, for some applications, upgrading the size of the single machine will give you the same power as adding several smaller machines, but increasing the size of the single machine, while usually these easiest thing to do at first, should not be considered autoscaling and has its own drawbacks. Here are some things to consider:
You need to be able to figuratively 'pull the plug' at any instant on any of the machines in your ASG without losing data.
Ultimately a properly setup auto-scaling solution will likely serve you better, but without doubt it is simpler to just 'buy a bigger machine' and the extra money you spend on running that bigger machine may be more than offset by the time and effort you don't have to spend re-architecting your solution to properly run in an autoscaling environment. The unique requirements of your solution will ultimately decide which approach is better.
Upvotes: 2