Troubleshooting

Improving Oracle OLTP database performance with Dell Fluid Cache for DAS
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This whitepaper studies the performance of an Oracle OLTP database in a Fluid Cache based solution. It
compares the performance of the Fluid Cache based solution against a traditional HDD-based storage
solution used as the baseline configuration.
The following sub-section introduces the Fluid Cache for DAS product, and the following section
describes the design and reference architecture of the baseline and the Fluid Cache based storage
solution evaluated in this whitepaper. The test methodology used in the study is then described.
Comparative performance results and analysis follow. The paper ends with a conclusion on the best use
case environments that can benefit from Fluid Cache based storage solution.
This paper also includes several appendices that provide details of the hardware, software, test tools,
and other configuration and tuning details that were relevant to this study. An appendix also provides
the next steps for customers who are interested in purchasing this reference architecture.
Dell Fluid Cache for DAS Overview
Dell Fluid Cache for DAS (Fluid Cache) is a host caching software that allows you to create a virtual
cache pool on supported Dell PowerEdge systems. For the rest of this paper, Dell Fluid Cache for DAS
will be referred to as “Fluid Cache for DAS” or “Fluid Cache.”
Fluid Cache uses Dell PowerEdge Express Flash PCIe SSDs installed on supported Dell systems to provide
a read and write cache pool. You can install up to four PCIe SSDs in a Dell system. The supported PCIe
SSD capacities are 175 GB and 350 GB. These PCIe SSDs can be combined to create cache pool capacity
ranging from a minimum of 175 GB to a maximum of 1400 GB. The cache pool is used to accelerate
response times with significant improvements in input/output operations per second (IOPS).
Some of the features of the Fluid Cache software are:
 Faster cache reads, writes, read-after-writes, and re-reads
 Data protection, as writes are replicated across multiple PCIe SSDs
 Orderly hot swap and hot plug capability that allows adding or removing a device without
halting or rebooting the system
 Support of two modes of write operation: write-back and write-through
The Fluid Cache for DAS cache pool stays persistent through reboots and the cache pool is highly-
available and resilient to failures. It ensures write cache data protection by utilizing unique journaling
and block replication technology. It actively and intelligently caches data at the block level and keeps
frequently accessed data sets on high-performance Express Flash PCIe SSD storage. This greatly reduces
latency and accelerates response times for Linux Oracle applications.
More information about Fluid Cache for DAS can be found in the user’s guide at
http://www.dell.com/support.
Solution design and reference architecture
The Fluid Cache software used in this whitepaper supports only DAS environments, and hence the scope
of the study in this whitepaper is limited to DAS-based solutions.