www.SanDisk.com 951 SanDisk Drive, Milpitas, CA 95035Improve
Business Productivity andUser Experience with a SanDisk PoweredSQL
Server 2014 In-Memory OLTP DatabaseWHITE PAPER Improve Business
Productivity and User Experience 2Table of ContentsExecutive
Summary
........................................................................................................................................................................
3Introduction: In-Memory Meets Fusion ioMemory
....................................................................................................................
4What Is In-Memory OLTP?
........................................................................................................................................................................................
4Unleash SQL Server 2014 In-Memory OLTP Database From I/O
Constraints
.......................................................................................5Eliminate
Continuous Checkpoint Slowdowns
............................................................................................................................................5Improve
HA and Maintenance by Accelerating Reboots, Restarts, and Failovers
.........................................................................5About
the Tests
...............................................................................................................................................................................
6Server Conguration
...................................................................................................................................................................................................
6Storage Conguration
................................................................................................................................................................................................
6Operating System Conguration
............................................................................................................................................................................7SQL
Server 2014 Conguration: Dell PowerEdge R720
.................................................................................................................................7Workload
Conguration
.............................................................................................................................................................................................7Test
Results
.....................................................................................................................................................................................
840GB In-Memory OLTP Transactional Workload Test Results
....................................................................................................................8Overall
Performance
..............................................................................................................................................................................................8Memory-Optimized
Filegroup Performance
................................................................................................................................................
9Transaction Log Performance
..........................................................................................................................................................................10Database
Startup Tests
.............................................................................................................................................................................................
12Database Startup Performance
.......................................................................................................................................................................
12Scaling Beyond 12,000 Users
.................................................................................................................................................................................
13Summary
.........................................................................................................................................................................................14Appendix
A: Is SQL Server In-Memory OLTP Right for You?
..................................................................................................
15Table Usage Analysis
................................................................................................................................................................................................
25Table Contention Analysis
................................................................................................................................................................................
27Stored Procedure Usage
Analysis..................................................................................................................................................................
28Memory Optimization Advisor
........................................................................................................................................................................
29Native Compilation Advisor
...................................................................................................................................................................................
36 Improve Business Productivity and User Experience 3Executive
SummaryThere has been a lot of press recently about in-memory
databases, and with good reason: business user requests served from
memory are lightning-fast. An in-memory database can easily process
an order of magnitude more transactions per day, and is therefore
capable of order of magnitude greater business productivity. SQL
Server In-Memory OLTP allows specic key tables to be
memory-optimized while maintaining the investment in the T-SQL code
base. SQL Server In-Memory OLTP shows dramatic performance
increases in a typical system and allows business users to choose
which business objects should be placed in memory, based on
critical need.This paper shows how combining Fusion ioMemory
products with SQL Server In-Memory OLTP improves the customer
experience even more. It does this by improving system response
time and business productivity (transactional processing
capabilities), allowing more customers to be served per server, all
the while dramatically reducing costs compared to traditional
storage solutions.The following table summarizes results of
performance testing performed by SanDisk on a Dell PowerEdge R720
and validated by Microsoft. Business Value Key
PerformanceIndicators Enterprise-Class Disk Array with 2014 SQL
ServerIn-Memory OLTPioDrive2 Duo 2.4TB with SQL Server 2014
In-Memory OLTP Business ProcessImprovementImprove
CustomerExperience User Transaction Wait Time () 1329 117Reduced
user wait timesby 91%Serve More Customers Transaction Throughput
(MB/s) 42 172Increased throughputby 409%Improve
BusinessProductivityTotal Transactions Processed(over 45
minutes)6,362,883 28,328,639Processed 445%more transactionsDeliver
on Internal Service Level AgreementsDatabase Startup Time (sec) 222
72Reduced startup timeby 67% Improve Business Productivity and User
Experience 4Introduction: In-Memory Meets Fusion ioMemoryWhile SQL
Server 2014 In-Memory OLTP brings never-before-seen performance
levels and capabilities to SQL Server databases, these new
capabilities require a storage subsystem that delivers consistent
low latency, ultra-high bandwidth, and strong reliability. Backing
SQL Server In-Memory OLTP databases with Fusion ioMemory products
is critical in driving the highest transaction performance levels.
This is done with the simplest, most cost-efective approach,
compared to legacy storage architecture.What Is In-Memory
OLTP?In-Memory OLTP is a memory-optimized database engine for SQL
Server 2014. In-Memory OLTP enables transactional database
applications to signicantly improve transactional throughput by
providing contention-free access to tables, by way of native
code.Other In-Memory database platform oferings often require
re-tooling application code. This could be due to the need for
deploying a new data access method, or even having enough RAM to
house the entire database. SQL Server 2014 does not require the
entire database to be placed into RAM the developer can choose
which tables would benet the most from becoming memory-optimized
tables. While there are some restrictions as to data types that may
be a part of a memory-optimized table, the base data types are
supported. Stored procedures that access the selected
memoryoptimized tables may be compiled into native code, which
executes faster. The end result is that much of the T-SQL code can
be leveraged, taking advantage of new SQL Server In-Memory OLTP
paradigms where the most value can be gained.Even when there is
enough RAM in the server to hold the entire database in memory, SQL
Servers access mechanism still operates on the concept of a page of
data. It goes through the process of latching and locking to ensure
data consistency. SQL Server In-Memory OLTP has an optimistic
approach to concurrency. There is no latching or locking, but there
is a mechanism to detect conict based on row versioning. Also,
there is no longer a concept of a page of data within the SQL
Server In-Memory data structures. With no pages to latch or lock,
there is a signicant improvement in performance, as there is no
waiting on resource availability and execution is unleashed.
Improve Business Productivity and User Experience 5Unleash SQL
Server 2014 In-Memory OLTP Database From I/O ConstraintsNo matter
how powerful the database system, performance will always be
limited at some point by chokepoints and bottlenecks. Fusion
ioMemory products resolve several I/O bottlenecks to raise the bar
on capabilities for SQL Server 2014 In- Memory OLTP
database.ELIMINATE CONTINUOUS CHECKPOINT SLOWDOWNSTo ensure
durability, SQL Server In-Memory OLTP relies heavily on the NTFS le
system to store data and delta les in a database le group optimized
for in-memory data. SQL Server In-Memory OLTP uses an ofine
checkpoint process to track and manage inserted and deleted data.
This generates a considerable amount of sequential disk I/O
activity and increases transaction log activity.Write performance
is key as transaction log activity is increased. This is due to the
highly concurrent, contention-free transactions generated in
memory. Fusion ioMemory products direct-path architecture provide
industry-leading, near-DRAM write performance, which is often
overlooked when discussing ash storage. This architecture enables
performance more efectively than SSDs do, because SSDs place
traditional storage protocols and RAID controllers between the data
and the application, making it much more difcult to deliver
consistent write performance.IMPROVE HA AND MAINTENANCE BY
ACCELERATING REBOOTS, RESTARTS, AND FAILOVERSIn addition to the
continuous checkpoint process, SQL Server In-Memory OLTP benets by
reading data in parallel. The parallel read process happens a) when
loading data from the data and delta les into memory during a
server reboot, b) when restarting the SQL Server service, or c)
when setting the database ofine. This process generates random I/O
and relies on a high-performing disk subsystem to load tables into
memory. The closer the data is to the CPU, the faster it will load
into memory. As with the continuous checkpoint, Fusion ioMemory
products direct-path architecture gives the database server CPUs
direct access to the data and delta les, which accelerates reboots,
restarts, and failover processes. Improve Business Productivity and
User Experience 6About the TestsTesting compared performance of an
ioDrive2 Duo 2.4TB card in a Dell PowerEdge R720 server to an
enterprise-class disk array in three key areas:1.Transactional
Performance. How the two systems performed under the heavy I/O
workload generated by the in-memory transaction log activity and
continuous checkpoints. Tests were conducted on latency
(responsiveness), and bandwidth (transactional workload) with
12,000 users.2.Database Startup. As the database is running out of
memory on servers, loading the database quickly becomes a key
factor in system resilience. We tested how fast the transactional
database could be brought online to compare how the two systems
would handle a server reboot or cluster failover event.3.User Load.
Tests were limited to 12,000 users because, at that point, the disk
array started experiencing timeouts. Additional testing measured
the total user load of a Fusion ioMemory system to demonstrate an
additional aspect of scalability.Server CongurationThe following
settings were enabled in the BIOS:Logical Processor was enabled.
With Hyper-threading enabled, we were able to increase the number
of users by 8000 in further testing.System Prole Settings was set
to performance.Virtualization was disabled.Fan Ofset was set to
high.Node Interleaving was disabled.Storage CongurationOne ioDrive2
Duo 2.4TB card was used as the storage for the in-memory database
within the Dell R720 server. The ioDrive2 Duo product appears as
two physical block devices to the host operating system. One block
device was used for the memory-optimized legroup and disk-based
legroup. The remaining block device was used exclusively for the
transaction log. The enterprise class storage array was congured
with two storage pools. The rst storage pool was comprised of 12
spindles and was used to store the memory-optimized le group, the
disk-based data les, and tempdb. The second storage pool was
comprised of 12 spindles and was used exclusively for the in-memory
database transaction log. Improve Business Productivity and User
Experience 7Figure 1. Storage layout of enterprise class disk array
and Fusion ioMemory ioDrive2 Duo 2.4TB card. Note: Neither tempdb
nor the disk-based tables were accessed during testing. All tables
were marked for in-memory use.Operating System CongurationWe used
the Interrupt-Afnity Policy Tool to bind the ioDrive2 card
interrupts to CPU0. The Interrupt-Afnity Policy Tool can be found
at http://msdn.microsoft.com/en-us/windows/hardware/gg463378.SQL
Server 2014 Conguration: Dell PowerEdge R720Name Baseline Values
Fusion ioMemory ValuesTransactional Database data les1 per core1
per core Tempdb data les1 per core1 per core Max Degree of
Parallelism 1 1Min/Max Server Memory (MB) 256,000 256,000Lock Pages
in MemoryEnabled EnabledWorkload CongurationA custom benchmark
application generated a transactional workload on the systems. The
benchmark application was congured with the following
parameters.Parameter ValuesDuration 45 minutesIn-Memory OLTP
Database Size 30GBUsers to generate load 12,000User Delay (ms)
0Repeat Delay (ms) 0Minutes of Ramp Time0 Improve Business
Productivity and User Experience 8Test ResultsThis section shows
the test results by each category of test: transactional workload
performance and database start-up performance. The transactional
workload performance results are shown by category: overall
performance, memoryoptimized legroup performance, and transaction
log performance.The charts reect testing with a scale of 12,000
users because the storage arrays capabilities peaked at that
workload. Testing beyond a 12,000 user load resulted in timeouts
with In-Memory OLTP, which stopped data processing for extended
periods of time.40GB In-Memory OLTP Transactional Workload Test
ResultsOVERALL PERFORMANCEThe chart below shows a summarized view
of the transactional performance testing results. Across all
performance indicators, Fusion ioMemory technology increases
business productivity by providing more transactional throughput
with signicantly lower latency.Figure 2. Fusion ioMemory products
increase In-Memory OLTP performance more efectively than an
enterprise disk Improve Business Productivity and User Experience
9MEMORY-OPTIMIZED FILEGROUP PERFORMANCEOne set of tests compared
write bandwidth and latency of Fusion ioMemory products to an
enterprise disk array to see how each handled the impact of
background processes, such as continuous checkpoint. As the charts
show, the Fusion ioMemory system delivers consistent high
performance, which helps ensure durability.Figure 3. Fusion
ioMemory products enable 84% faster in-memory checkpoint processes
with much less variation.Figure 4. Continuous checkpoints are
faster due to 75% higher average bandwidth. Improve Business
Productivity and User Experience 10TRANSACTION LOG PERFORMANCEThe
in-memory database results in much greater workload on transaction
logs. Slow I/O on the transaction log reduces database performance.
Tests measured the average and maximum transactions per second that
the two systems completed over a 45-minute period. Tests also
measured latency to compare transactional processing speeds to show
the responsiveness of the database under load, and the speed it can
serve individual requests. Fusion ioMemory products completed 4.5x
more transactions over the test period, and did so with much higher
response times, thus making each database server more
scalable.Figure 5. Fusion ioMemory system enables 4.4X more user
transactions per second.Figure 6. 76% faster continuous checkpoint
performance increases transactional processing speeds and business
productivity. Improve Business Productivity and User Experience
11Figure 7. 91% lower latency delivers consistently fast response
times, which improves the user experience and helps IT condently
meet SLAs.Figure 8. 4X faster transaction log writes eliminates I/O
slowdowns. Improve Business Productivity and User Experience
12Database Startup TestsDATABASE STARTUP PERFORMANCEThe database
startup test measured how long it took to load 120GB of data into
DRAM. As the chart below shows, thedata loaded in 72 seconds from
the ioDrive2 Duo, as opposed to 222 seconds from the disk arrayor
308% faster. Thisperformance increases system resilience and
facilitates maintenance, enabling organizations to deliver on
internalService Level Agreements (SLAs).Figure 9. Database startup
on Fusion ioMemory is 308% faster than from an enterprise disk
array. Improve Business Productivity and User Experience 13Scaling
Beyond 12,000 UsersIn addition to testing transaction processing
scalability, its useful to know the user load each server can
support. Accordingly, testing was extended beyond 12,000 users. As
stated above, our storage array testing peaked at 12,000 users due
to severe write latency. With the Fusion ioMemory solution, our
scalability test peaked at 24,000 users before processor
utilization reached 80%.Figure 10. With 24,000 users write latency
consistently stays under 220 microseconds. Improve Business
Productivity and User Experience 14Figure 11. Database transactions
average 109,000 per second once all 24,000 users are on the
system.SummaryFusion ioMemory products extend the power of SQL
Server 2014 In-Memory OLTP databases by removing I/O bottlenecks
associated with transaction logs and checkpoints that become more
severe under the workload of an inmemory database. They also
increase startup, reboot, and failover speeds to increase
resiliency. Finally, they also increase the user load each server
can support. The table below summarizes the benets. Business Value
Key PerformanceIndicators Enterprise-Class Disk Array with 2014 SQL
ServerIn-Memory OLTPioDrive2 Duo 2.4TB with SQL Server 2014
In-Memory OLTP Business ProcessImprovementImprove
CustomerExperience User Transaction Wait Time () 1329 117Reduced
user wait timesby 91%Serve More Customers Transaction Throughput
(MB/s) 42 172Increased throughputby 409%Improve
BusinessProductivityTotal Transactions Processed(over 45
minutes)6,362,883 28,328,639Processed 445%more transactionsDeliver
on Internal Service Level AgreementsDatabase Startup Time (sec) 222
72Reduced startup timeby 67% Improve Business Productivity and User
Experience 15Appendix AAppendix A: Is SQL Server In-Memory OLTP
Right for You?On the surface, workloads that are characterized by a
high amount of latching or locking would be classied as good
candidates for the SQL Server 2014 In-Memory OLTP feature. While
that may be true, Microsoft SQL Server 2014 provides several
advisor tools and usage reports to help identify which tables and
stored procedures are the best candidates for storing in memory. It
is highly recommended that you a) congure the Management Data
Warehouse to collect usage analysis on tables and stored
procedures; and b) run the advisory tool to determine which tables
and stored procedures would benet from In-Memory OLTP. As mentioned
previously, a full database migration isnt required. Database
administrators have the exibility to move individual tables and
stored procedures into SQL Server In-Memory OLTP. More information
on In-Memory OLTP migration can be found
here:http://msdn.microsoft.com/en-us/library/dn247639(v=sql.120).aspxBelow
is the step-by-step procedure to analyze and migrate data:1.Congure
the Management Data Warehouse (Data Collection > Tasks >
Congure Management Data Warehouse). Improve Business Productivity
and User Experience 16Appendix A2.Click Next to progress through
the wizard. Improve Business Productivity and User Experience
17Appendix A3.Create your Management Data Warehouse (MDW) database.
Improve Business Productivity and User Experience 18Appendix
A4.Select the appropriate server and newly created MDW database.
Improve Business Productivity and User Experience 19Appendix A5.Add
necessary logins and users. Improve Business Productivity and User
Experience 20Appendix A6.Verify actions and click Finish. Improve
Business Productivity and User Experience 21Appendix A7.Click
Close. Improve Business Productivity and User Experience 22Appendix
A8.Select the appropriate server and database. Check the box for
Transaction Performance Collection Analysis. Improve Business
Productivity and User Experience 23Appendix A9.Click Finish.
Improve Business Productivity and User Experience 24Appendix A10.
In Object Explorer navigate to Data Collection, right click Stored
Procedure Usage Analysis and select Start. Then right click Table
Usage Analysis and select Start. Improve Business Productivity and
User Experience 25Appendix A11.Right click the MDW database. Select
Reports > Management Data Warehouse > Transaction Performance
Analysis Overview. The AMR tool for In-Memory OLTP opens.Table
Usage AnalysisIn the AMR tool for In-Memory OLTP you can view
analysis on tables, stored procedure usage, and table contention.
Improve Business Productivity and User Experience 26Appendix AThe
Table Usage chart illustrates which tables would benet from SQL
Server In-Memory OLTP, based on usage. The chart also illustrates
the degree of migration difculty. Improve Business Productivity and
User Experience 27Appendix ATABLE CONTENTION ANALYSISThe Table
Contention chart illustrates which tables would benet from
In-Memory OLTP, based on table contention. The chart also
illustrates the degree of migration difculty. Improve Business
Productivity and User Experience 28Appendix ASTORED PROCEDURE USAGE
ANALYSISThe Stored Procedure report uses a bar chart to identify
which procedures will be benet from In-Memory OLTP based on usage,
with CPU time measured in milliseconds. Improve Business
Productivity and User Experience 29Appendix AMEMORY OPTIMIZATION
ADVISORBefore starting a table migration to In-Memory OLTP, we
recommend reading the migration information on Microsoft TechNet at
http://technet.microsoft.com/en-us/library/dn247639(v=sql.120).aspx.Below
is a step-by-step procedure for migrating tables:1.This advisor is
based on the recommendations from the AMR reports. Right click the
table to migrate and select Memory Optimizer Advisor. Improve
Business Productivity and User Experience 30Appendix A2.Follow the
screens in the wizard. Improve Business Productivity and User
Experience 31Appendix A3.If necessary, x the items that failed
during the Memory Optimization Checklist step. Click Next. Improve
Business Productivity and User Experience 32Appendix A4.Fix all
warnings to ensure a smooth migration. Improve Business
Productivity and User Experience 33Appendix A5.Name the
memory-optimized le group, change the logical le name if necessary,
and change the table name. Improve Business Productivity and User
Experience 34Appendix A6.Select the appropriate primary key
column(s) and hash bucket size for the non-clustered index. Click
Next. Improve Business Productivity and User Experience 35Appendix
A7.Complete the migration. Improve Business Productivity and User
Experience 36Appendix ANative Compilation AdvisorBelow is a
step-by-step procedure for using the Native Compilation
Advisor:1.Click Next. Improve Business Productivity and User
Experience 37Appendix A2.Fix the code in the stored procedure
associated with the warnings listed in the dialog. Improve Business
Productivity and User Experience 38Appendix A3.Develop workarounds
for unsupported TSQL elements.FOR MORE INFORMATIONContact a SanDisk
representative, 1-800-578-6007 or [email protected]
performance results discussed herein are based on testing and use
of the above discussed products.Results and performance may vary
according to congurations and systems, including drive capacity,
system architecture and applications. 2014 SanDisk Corporation. All
rights reserved. SanDisk is a trademark of SanDisk Corporation,
registered in the United States and other countries. Fusion
ioMemory, ioDrive, and others are trademarks of SanDisk Enterprise
IP LLC. Other brand names mentioned herein are for identication
purposes only and may be the trademarks of their respective
holder(s).
