sap 2-tier vs 3-tier comparison nov13

IBM SAP International Competence Center

Copyright IBM Corp. 2013

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Comparison of SAP Application Performance

on Centralized versus Distributed Server Topologies

This document can be found on the web, www.ibm.com/support/techdocs

Date: November 2013

Walter Orb Matthias Kchl Fabrice Moyen

Hans-Jrgen Reiss

IBM SAP International Competence Center Walldorf, Germany
http://www.ibm.com/support/techdocs



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Table of contents

TABLE OF CONTENTS ..................................................................................................................................... 2

FIGURES ........................................................................................................................................................ 3

TABLES .......................................................................................................................................................... 3

1. INTRODUCTION ..................................................................................................................................... 4

ACKNOWLEDGEMENTS ........................................................................................................................................... 4

2. TRADITIONAL SAP BUSINESS SUITE TOPOLOGIES .................................................................................. 5

COMMUNICATION BETWEEN APPLICATION SERVER AND DATABASE ................................................................................. 5

3. DESCRIPTION OF TEST ENVIRONMENT .................................................................................................. 6

HARDWARE AND NETWORK SETUP ........................................................................................................................... 6 TESTED TOPOLOGIES .............................................................................................................................................. 7

SAP 2-tier ...................................................................................................................................................... 7 - -tier-in-a-box ................................................................................................. 7

SAP 3-tier ...................................................................................................................................................... 8 3-tier Campus/Cloud Simulation................................................................................................................... 8

SAP WORKLOAD SCENARIOS ................................................................................................................................... 9 NIPING Network Round-Trip Time (RTT) .................................................................................................... 9 SAP ERP Workload Simulation .................................................................................................................... 10 DB ROW-Select ........................................................................................................................................... 11 SAP Client Copy ........................................................................................................................................... 11

4. RESULT ANALYSIS ................................................................................................................................ 13

NIPING NETWORK ROUND-TRIP TIMES .................................................................................................................. 13 INTERACTIVE SAP WORKLOAD ............................................................................................................................... 17 SAP BACKGROUND PROCESSING ............................................................................................................................ 19

DB-Select Simulation [SINGLE_MULTI_READ] by SAP................................................................................. 19 SAP Client Copy ........................................................................................................................................... 20

WIDE AREA NETWORK SIMULATION ....................................................................................................................... 23 NIPING Network Round-Trip Times ............................................................................................................ 23 Interactive SAP Workload ........................................................................................................................... 24 SAP Background Processing ....................................................................................................................... 25 SAP Client Copy ........................................................................................................................................... 26 SAP - SD Queries [DB_READ_UPDATE] ....................................................................................................... 27

5. POWER SYSTEMS (AIX) SPECIFIC OBSERVATIONS ................................................................................ 29

ADAPTER / OS / NETWORK SETTINGS ..................................................................................................................... 29 VIO UTILIZATION ................................................................................................................................................ 31

6. SUMMARY ........................................................................................................................................... 33

7. TECHNICAL APPENDIX ......................................................................................................................... 34

DETAILED TEST LANDSCAPE NETWORK LAYOUT AT IBM CLIENT CENTER IN MONTPELLIER ................................................. 34 ANUE NETWORK LATENCY SIMULATOR .................................................................................................................. 36

8. ABOUT THE AUTHORS ......................................................................................................................... 38

9. TRADEMARKS AND SPECIAL NOTICES .................................................................................................. 39



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Figures

FIGURE 1 SAP APPLICATION TIERS ............................................................................................................................... 5 FIGURE 2 SCHEMATICS OF TEST-ENVIRONMENT .............................................................................................................. 6 FIGURE 3 TESTED TOPOLOGIES..................................................................................................................................... 7 FIGURE 4 NIPING ROUND-TRIP TIMES ........................................................................................................................ 15 FIGURE 5 LARGE PACKETS BANDWIDTH DBAPP-SERVER ............................................................................................. 16 FIGURE 6 SAP ERP DB-DIALOG TIMES ....................................................................................................................... 17 FIGURE 7 INCREASE OF SAP ERP SD DB-REQUEST TIMES VS. 2-TIER ................................................................................ 17 FIGURE 8 ROW SELECT TIME OVER QUERY RESULT VOLUME .............................................................................................. 19 FIGURE 9 SAP CLIENT COPY ELAPSED RUNTIME ............................................................................................................. 20 FIGURE 10 INCREASE OF SAP CLIENT COPY PROCESSING TIME VS. 2-TIER ........................................................................... 21 FIGURE 11 PARALLEL CLIENT COPY PROCESSES .............................................................................................................. 22 FIGURE 12 ANUE DELAY VERIFICATION BY NIPING ......................................................................................................... 23 FIGURE 13 ERP DB-WAN RESPONSE TIME ................................................................................................................. 24 FIGURE 14 EXPONENTIAL INCREASES IN GUI RESPONSE TIME ........................................................................................... 25 FIGURE 15 DB-BACKGROUND PROCESSING SELECT TIMES (ZTEST-ABAP) ........................................................................ 26 FIGURE 16 3-TIER CLIENT COPY RUNTIME OVER APP-SERVER. LATENCY ............................................................................. 27 FIGURE 17 DB SELECT MIX REPORT ........................................................................................................................... 28 FIGURE 18 IMPACT OF ETHERNET ADAPTER TUNING ON ROUND-TRIP TIMES (IN MS) ............................................................. 30 FIGURE 19 NETWORK ROUND-TRIP TIMES (IN MS) USING DIFFERENT PROCESSOR MODES FOR VIO SERVERS .............................. 31

Tables

TABLE 1 CATEGORIZED RESULT SERIES.......................................................................................................................... 13 TABLE 2 LAN ROUND-TRIP TIMES ............................................................................................................................... 14 TABLE 3 NIPING ROUND-TRIP TIMES ............................................................................................................................ 15 TABLE 4 INCREMENTAL DB-REQUEST TIME VS. 2-TIER .................................................................................................... 18 TABLE 5 INCREMENTAL CLIENT COPY RUNTIME VS. 2-TIER ............................................................................................... 21 TABLE 6 PARALLELIZATION GAINS OF CLIENT COPY ......................................................................................................... 22 TABLE 7 INCREASE OF DB-REQUEST TIME IN WAN VS. 2-TIER ......................................................................................... 25
file:///C:/_Projekte/MOP_2tier_3tier/SAP_2-tier_vs_3-tier_Comparison.docx%23_Toc372294530



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1. Introduction

Today w e see a continued trend towards 3 - tier client/server implementations at SAP

customers. In combination with virtualized platforms, this provides a high degree in

flexibility and agility.

However, 3- tier topologies introduce a new level of network complexity and

performance impact (latency , bandwidth) compared to a centralized 2 - tier SAP system

setup. This is even more important when we compare the speedup of CPUs, I/Os (SSD,

Flash ) versus network evolution during the past years.

Further more, SAP customers start accommodating the cloud computing paradigm and

application server resources for special purposes (e.g. peak

load processing , SAP upgrade s). This introduces wide -area -network effects to their SAP

applicati ons. Obviously, t he influence of the network c an become the dominating factor

for response and processing time.

The IBM SAP In ternational Competence Center in Walldorf together with the IBM Client

Center in Montpellier conducted a compre hensive series of measurements to quantify

the impact of 2- tier versus 3 - tier topologies for differe nt SAP workload characteristics.

The results of this study are represented and commented in this paper.

The SAP AG p erformance team contributed with know -how and test reports .

Acknowledgements

Special Thanks To :

Thomas Glaser, IBM Power Systems Technical Sales Manager Europe , for his

overall project sponsorship.

Dr . Ulrich Marquard, Senior Vice President and H ead of Performance, Data

Management & Scalability at SAP AG Germany, and his team for providing

valuable test cases, consulting, and contribution while performing the tests and

editing this document.



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2. Traditional SAP Business Suite Topologies

The SAP Business Suite bac kend architecture comp rises of three layers, a database , an

application , and a presentation layer . These layers can be deployed in either 2 - tier

mode (DB and applica tion server processes run within a s ingle OS image ) , or as a 3 - tier

configuration w here the database and applicat ion layers run in separate OS images and

have to communicate via a logical or physical network connection. The first tier is the

presentation layer .

Figure 1 SAP Application Tiers

Each topology has different characteristics in regard to complexity, flexibility and

resiliency.

Communication between Application Server and Database

The introduction of an additional TCP/IP network stack between the database and

application servers for 3 - tier configuration has an impact on SAP transaction response

and the runtime of background jobs . In 2 - tier implementations (d ependent on the used

database version) the database client to server communication path can be optimized

to use an inter -process communication method . In a 3 - tier configu ration , database

accesses always have to pass through the TCP/IP software stack as well as through

some virtual (hypervisor) or physical ( network interface adapter, LAN switches, WAN)

communication layer.

Each database access from the application s erver needs to pass through the complete

TCP/IP layer twice: first issuing a DB - request (s elect, update etc. ) and then receiving

the results, either in form of selected business data or a transaction commit .



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3. Description of test environment

Hardware and Network Setup

The i nfrastructure was set up and operated at the Montpellier IBM Client Center. The

SAP related tests were executed remotely by members of the IBM SAP C ompetence

Center in Walldorf via VPN access.

The following components were used to build the test landscape:

2x IBM Power 750 servers (model 8408 -E8D)

o 32 -core POWER7+ CPUs at 4GHz with 1TB of RAM

o Dual Virtual I/O servers at level 2.2.2.2 (with efix IV37111m2a,

IV38225s2a, IV39725m2a)

o All l ogical partitions at AIX level 7.1 TL2 SP2

IBM Storwize V7000 Storage Subsystems (model 2076 -324)

o FC-attached

Dedicated network and SAN infrastructure

o 1Gb and 10Gb Ethernet LAN adapters and switches

o 8Gb fibre SAN a dapters and switches

ANUE Network Latency Simulator

o 2 x 1Gb Ethernet ports

Figure 2 Schematics of Test-Environment

A symmetric Ether Channel connection between the two servers was chosen to resemble

realistic customer setups . Configuration details are shown on page 34 in the Technical

Appendix section.

The main focus of the test scenarios was to evaluate the impact o f different network

topologies on database request times and subsequently th e transaction response and



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runtimes of background job s. To avoid any other load dependent influencing factors,

the workloads and the partitions were sized so that CPU and memory ut ilization did not

create any bottlenecks . The maximum CPU utilization on each partition was kept in the

30 -40% range.

Tested Topologies

SAP 2-tier

SAP workload is processed within a single partition ( beaci01 ) .

No external network traffic between database and application

server processes is required for transaction processing.

For all test series in this paper the database and SAP Central

Services remain ed on this partition. Only the a pplication

workload was executed and measured on other partitions .

- -tier-in-a-box

An additional SAP application server instance is ho sted within a

second partition ( beaas12 ) on the same physical server .

Communication via virtualized Ethernet adapters is provided by

the PowerVM hypervisor using the integrated virtual Ethernet

capabilities .

Figure 3 Tested Topologies



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SAP 3-tier

The applicat ion server resides on

another partition ( beaas21 ) on a

second physical server .

The partition setup was identical t o

beaas12. TCP/IP traffic ha d to

pass through the VIO server

partitions and physical network

segments.

For the dedicated adapter tests,

the Ethernet adapters were

assigned directly to partitions

beaci01 and beaas21 . Thus any

additional latency induced by the

VIO servers was eliminated for

these test series .

3-tier Campus/Cloud Simulation

Same as the SAP 3 - tier scenario

with a latency simula tion device

(ANUE) added to the external

communication path. Although a

single physical device, simulated

latency time was split 50:50

across the two network paths

(inbound and outbound) during

our test series. The time delays on

both network path s were set

between 0 and 125 ms, the

resulting round - trip delay

experienced by the applications

was two times this time delay .

See page 36 for more d etails about the ANUE device .

sap 2-tier vs 3-tier comparison nov13

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