Accelerating Database Applications on Linux Servers

Introducing OCZ’s LXL Software - Delivering a Data-Path Optimized Solution for Flash Acceleration

Allon Cohen, PhD
Yaron Klein
Eli Ben Namer
Scott Harlin

Published Janaury 2013

Introduction

As enterprise database applications are data access-intensive their performance is highly dependent on I/O latencies and bandwidths. The speed of data access for a particular database system implementation determines the time it takes to locate, analyze and process data, and ultimately dictates whether users receive the business insight they need, when they need it. To enable a large number of users to be serviced without contention, and to maximize the user experience of their database applications, the underlying enterprise storage latency and transactional IOPS (input/output operations per second) must deliver optimal performance.

Immediate access to data becomes especially critical during periods of peak usage so that user productivity is not adversely affected. For example, bulk access rates and database read latencies can significantly impact the time it takes to complete data warehouse queries in enterprise and cloud environments. As database performance is affected by both the hardware and software of any given project, it must be optimized at the system level.

Solid-state drive (SSD) flash memory provides a perfect fit for the data access requirements of modern databases through its support of ultra-low latencies and the ability to efficiently handle randomized data access requests. In particular, PCI Express (PCIe) flash-based SSDs, when placed directly on the server’s PCIe bus (and in very close proximity to the data hungry CPUs), provide an even further reduction in access latencies. However, as database capacities grow beyond a certain point, it can become impractical or ‘cost-ineffective’ to place all of the database tables on SSD flash.

In such cases, the choice of what data to place in SSD flash becomes critical. On one hand, if the system neglects to find and place important data, system performance will drop as a result of cache misses. On the other hand, if the system places unimportant data in SSD flash, critical data might be displaced and no longer available for low latency CPU access. Therefore, the caching mechanism must possess the capability to intelligently choose what data to place in flash and when to place it.

This white paper presents a solution that dramatically increases database transactional IOPS performance, reduces database read latencies, and significantly improves query completion times for Linux-based servers. The solution includes OCZ’s host-based PCIe Z-Drive R4 SSD Series in combination with OCZ’s Linux Acceleration (LXL) caching software. By introducing this combined hardware/software solution into a Linux environment (running an enterprise database application such as Oracle 11g), OCZ demonstrates query processing improvements by factors up to 1700%.

Table of Contents

  1. Introduction
  2. Introducing LXL Software and Direct Pass Caching Technology
  3. How OCZ Direct Pass Caching Works
  4. The Effectiveness of OCZ Direct Pass Caching
  5. Performance Testing Using an Oracle 11g Database
  6. Performance Testing on Linux-Based Virtualization Platforms
  7. Conclusion