Rotational Disks--Supported?


#1

I am in the very (!) early stages of evaluating Aerospike. One of the first things I need to understand is the deployment/server/hardware requirements. There seems to be conflicting information about whether hard disks can be used for data storage.

The FAQ has this Q/A:

Can I store data on hard disk rather than SSD?

No. The Aerospike database is intended to be a high performance, low-latency database. Because of this, the physical limitations of rotational disks add an unacceptable amount of latency to the data.

This page says the following:

Aerospike can store data in DRAM, traditional rotational media, and SSDs, and each namespace can be configured separately.

Also, the first diagram on this page also references Rotational Disk or SSD.

My best guess is that an HDD can be used to store data permanently, but the data gets loaded into memory at startup, where an SSD acts as both memory and permanent storage?

Can someone clarify?


#2

Hi Phil

You have it right. Let me elaborate.

A Namespace, among other things, is a storage definition. There are essentially 2 storage options:

  • RAM optionally backed by HDD
  • SSD

Aerospike indexes are always stored in RAM, so they are very fast. But the actual data will either be stored in RAM or SSD depending on the Namespace definition.

So what do you need for a development server? This depends on how much data you are going to need for purely development (as apposed to testing). I routinely develop on my Mac running a single node cluster in Virtual Box/ Vagrant. In this case I configure a namespace with storage of RAM backed with HDD. When I need to develop against billions of records, I use a “real” cluster either in our office or on AWS.

Hope this helps

Peter