Prior posts addressed the performance benefits of a shared cache tier (ScaleDB CAS) and also the storage flexibility it enables.This post compares the ScaleDB CAS purpose-built file storage sharing system against off-the-shelf solutions like NFS and various cluster file systems (CFS).

When using a clustered database, like ScaleDB, each node has full access to all of the data in the database. This means that the file system (SAN, NAS, Cloud, etc.) must allow multiple nodes to share the data in the file system.

Options include:
1. Network File System (NFS)
2. Cluster File System (CFS)
3. Purpose-built file storage interface

Locking Granularity:
I won’t get deeply …

Any time you can get two for the price of one (a “2Fer”), you’re ahead of the game. By implementing our shared cache as a separate tier, you get (1) improved performance and (2) storage flexibility…a 2Fer.

What do I mean by storage flexibility? It means you can use enterprise storage, cloud storage or PC-based storage. Other shared-disk cluster databases require high-end enterprise storage like a NAS or SAN. This requirement was driven by the need for:

1. High-performance storage
2. Highly available storage
3. Multi-attach, or sharing data from a single volume of LUN across multiple nodes in the cluster.

Quite simply, you won’t see other shared-disk clustering databases using cloud storage or PC-based storage. However, the vast majority of MySQL users rely on PC-based storage, and most are not willing to pay the big bucks for high-end storage.

ScaleDB’s Cache …