CODEWITHSUNDEEP
amazon-web-servicesopensearchinstancetype
Carmella
Carmella

Reputation: 45

AWS OpenSearch Instance Types - better to have few bigger or more smaller instances?

I am a junior dev ops engineer and have this very basic question.

My team is currently working on providing an AWS OpenSearch cluster. Due to the type of our problem, we require the storage-optimized instances. From the amazon documentation I found that they recommend a minimum number of 3 nodes. The required storage size is known to me, in the OpenSearch Service pricing calculator I found that I can either choose 10 i3.large instances or 5 i3.xlarge ones. I checked the prices, they are the same.

So my question is, when I am faced with such a problem, do I choose the lesser bigger instances or the bigger number of smaller instances? I am particularly interested in the reason.

Thank you!

Upvotes: 2

Views: 4774

Answers (1)

ilvar
ilvar

Reputation: 5841

Each VM has some overhead for the OS so 10 smaller instances would have less compute and RAM available for ES in total than 5 larger instances. Also, if you just leave the default index settings (5 primary shards, 1 replica) and actively write to only 1 index at a time, you'll effectively have only 5 nodes indexing data for you (and these nodes will have less bandwidth because they are smaller).

So, I would usually recommend running a few larger instances instead of many smaller ones. There are some special cases where it won't be true (like a concurrent-search-heavy cluster) but for those, I'd recommend going with even larger instances in the first place.

Upvotes: 4

Related Questions