Pure Genius: How To Get Mainframe-Like Scalability & Availability For Midrange DB2 discusses pureScale, an optional feature for DB2 that implements shared-disk clustering to provide high scalability and availability. It can support up to 128 members. The architecture uses a shared database, coordination facilities, and InfiniBand networking. Customers experience scalability gains, easy installation, and resilience like continued operation despite coordination facility failure. The presentation evaluates pureScale's benefits and customer experiences.

1. Pure Genius: How To Get
Mainframe-Like Scalability &
Availability For Midrange DB2
The Information Management Specialists
Availability For Midrange DB2
James Gill & Julian Stuhler
GSE November 2010

2. Agenda
• pureScale Overview
Why should you care?
The Information Management Specialists
Architectural overview
• Experiences
Triton’s pureScale environment
Installation
Performance
Resilience

3. Why pureScale?
• Availability
Any system outage has direct impact on profitability and
customer retention
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customer retention
Serving multiple geographies makes planned downtime more
difficult
• Agility / Scalability
Almost every business has major workload spikes, with
significant unused capacity at other times
Need to be able to rapidly scale up/down in a cost effective way,
with little or no change needed to the application

4. What is pureScale?
• Optional feature for DB2 for Linux, UNIX and
Windows
Current support is for AIX on System p and
SUSE Linux on IBM System x servers only
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SUSE Linux on IBM System x servers only
• Implements a shared-disk clustering solution
to support high scalability and availability
Up to 128 members in initial release
• Based on proven “data sharing” technology
used in DB2 for z/OS for past 15 years
• Capacity-based charging model allows
cluster to be easily expanded/contracted
• Little or no application change required

5. pureScale Architecture
Primary CF Secondary
CF
GBP
GLM SCA
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Member A
Shared
Database
Member B Member C
IB Interconnect

6. Architecture - Members
Agents and threads
dbheap,
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Shared
Database
Log buffers
Bufferpools
Logs
dbheap,
sort heap,
etc

7. Architecture - CFs
SCA
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SCA
GBP
Directory
Data Pgs
Index Pgs
GLM
Hash table
Lock
entries

8. Architecture - Infiniband
• Low latency (1 – 1.3 microseconds)
• High speed (300Gb/s – EDR 12x)
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• High speed (300Gb/s – EDR 12x)
• RDMA – remote direct memory access
NIC managed
► No processor interrupt
► 5 – 30 microsecond access time

9. Architecture – Infiniband 2
The Information Management Specialists
www.infinibandta.org/content/pages.php?pg=technology_overview

10. pureScale Scalability
10.4
10
12
14Throughputv1Member
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1
1.98
3.9
7.6
0
2
4
6
8
0 2 4 6 8 10 12 14
Throughputv1Member
Number of pureScale Members
Source: Internal IBM Lab Tests

11. Practical Experiences
• Triton’s Commodity Cluster
• IBM’s nano-cluster
The Information Management Specialists
• IBM’s nano-cluster
• Architecture
• Installation
• Performance
• Resilience

12. Triton’s Commodity Cluster
• Objectives
Undertake basic validation of IBM’s performance &
scalability claims
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scalability claims
Build technical experience in a pureScale environment
and establish platform for ongoing R&D
Assist IBM with early beta testing
• Constraints
Budget < £1K
Easily portable for customer demos etc.

13. Commodity Cluster - Architecture
CF
The Information Management Specialists
Node 1 Node 2
1GB Ethernet
iSCSI
NAS
TE App
Server

14. Triton’s Commodity Cluster
• 2 member nodes and one CF
• Each node:
Intel D510M0 (Dual core 1GHz Atom)
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Intel D510M0 (Dual core 1GHz Atom)
4GB RAM
40GB SSD
• Shared disk
iSCSI 1TB (QNAP TS110)
• DB2 9.8 pureScale FP2 development image
• Technology Explorer used for workload and monitoring
www.sourceforge.net/projects/db2mc

15. IBM nanoCluster - Architecture
CF
node101 node102
App
Servers
CF
node103
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CF
1GB Ethernet
GPFS
Disk
member
CF
member

16. IBM’s pureScale nanoCluster
• 2 combined member and CF nodes
• One shared disk and app server tier node
• Each node:
The Information Management Specialists
• Each node:
Intel D510M0 (dual core 1GHz Atom)
4GB RAM
Disk
► 40GB SSD (pureScale nodes)
► 100GB 7200rpm SATA (shared disk/app server node)

17. Triton pureScale Experiences
• Installation experiences
SLES 10 requires
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SLES 10 requires
► compat-libstdc++-5.0.7-22.2.x86_64.rpm
db2cluster resolves iSCSI mount issues
Ensure FQDN names in /etc/hosts
Very slick considering the component count

18. Triton pureScale Experiences
• Commodity Cluster Performance
Technology Explorer
The Information Management Specialists
Technology Explorer
► WMD Java workload driver (WLB enabled)
► 2.5M row table
► Vanilla installation
► 32 threads, 25ms think time
Delivered 1000tps @ 95%CPU load

19. • 14 simulated client connections
• WLB ACR enabled
• 1ms think time
• 250,000 row table
Performance - nanoCluster
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• Delivering c. 5500tps @ 50% CPU load

20. Workload Balancing (WLB)
• Members track and share available capacity
db2pd –serverlist
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db2pd –serverlist
• Slipstreamed periodically to clients
DB2 9.7 FP1 or higher
• Transaction workload balance
On UR boundaries

21. WLB
• db2pd –serverlist
Database Member 0 -- Active -- Up 0 days 00:20:43
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Database Member 0 -- Active -- Up 0 days 00:20:43
Server List:
Time: Tue Nov 2 07:26:54
Database Name: DTW
Count: 2
Hostname Non-SSL Port SSL Port Priority
node102.purescale.demo 50001 0 52
node103.purescale.demo 50001 0 47

22. Resilience – CF Failure
• Simulate failure of the primary CF
db2lco@node102:~> db2instance -list
ID TYPE STATE HOME_HOST CURRENT_HOST ALERT PARTITION_NUMBER
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ID TYPE STATE HOME_HOST CURRENT_HOST ALERT PARTITION_NUMBER
-- ---- ----- --------- ------------ ----- ----------------
0 MEMBER STARTED node102 node102 NO 0
1 MEMBER STARTED node103 node103 NO 0
128 CF PRIMARY node102 node102 NO -
129 CF PEER node103 node103 NO -
HOSTNAME STATE INSTANCE_STOPPED ALERT
-------- ----- ---------------- -----
node103 ACTIVE NO NO
node102 ACTIVE NO NO
db2lco@node102:~> ps -ef | grep ca-server
db2lco 4158 4153 0 05:30 ? 00:00:31 ca-mgmnt-lwd -i128 -p56000 -k8521f27a -d/home/db2lco/sqllib/db2dump -
e/home/db2lco/sqllib/cf/ca-server -f
db2lco 4164 4158 18 05:30 ? 00:12:41 /home/db2lco/sqllib/cf/ca-server -i 128 -p 56000 -k 1474562 -s 0 -f
db2lco 32120 21933 0 06:37 pts/0 00:00:00 grep ca-server
db2lco@node102:~> kill -9 4164

23. Resilience – CF Failure - Impact
The Information Management Specialists

24. pureScale Summary
• Robust clustering technology based on a proven
architecture
Scalability
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Scalability
Resilience
• No code change to scale out
• Excellent price/performance characteristics
• Initial customer implementations are under way
• What are you waiting for?

25. Feedback / Questions
James Gill – james.gill@triton.co.uk
The Information Management Specialists
James Gill – james.gill@triton.co.uk
Julian Stuhler – julian.stuhler@triton.co.uk
www.triton.co.uk
pureScale webcast series each Tuesday