Transcript Lec 1

Server Platforms
Week 11- Lecture 1
Server Market - 2003
$ 46,100,000,000 ($ 46.1 Billion)
Gartner
Units
Market Sales
Company Share Value Sold - Q4
IBM
32.1%
$ 14.8
274,000
HP
27.1%
$ 12.5
462,000
SUN
11.7%
$ 5.4
84,000
Dell
8.7%
$4
319,000
Other
20.4%
$ 9.4
441,000
Total
100%
$ 46.1
1,580,000
Why are Servers important
• Turns data into information
• Major impact on TCO
• Organisational standards
Total Cost Of Ownership
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Hardware capital/recurrent cost
reliability cost
performance cost
OS software capital/recurrent costs
support personnel cost
training cost
scalability (hardware/software) cost
Organisation standards
• Most organisations of any size have
standards & buying arrangements with
suppliers
• Choice of server often dictated by OS,
applications and support personnel
experience
Main Components in the Server Platform
• Processors, memory & Storage
• Operating system
• DBMS – Database Management System
• Middleware
Server Classes
• Enterprise capable servers
– mainframes
– large Unix, eg Sun E 10000
– large clusters
• Small organisational or department servers
Mainframes still important
• Still popular in very large organisations
• Strong heritage of reliability in 7x24
• Move in some companies that went distributed to
go back to central machines
• Large Internet applications may give them a new
lease of life
• Sophisticated management software like WLM manages workloads according to user defined
priorities
IBM mainframe O/S
• IBM’s
– OS/400 for AS/400 now eServer iSeries 400
– Z/OS - OS/390 – MVS 1974 now supports
TCP/IP and Unix API & user interface
– VSE/ESA – on smaller 370 machines
– Z/VM for S390 Runs other operating systems
as guests. These now include Linux
Other Contenders in Enterprise Market
• Windows NT/2000
• Versions of Unix
– HP’s HP-UX
– IBM’s AIX
– Sun’s Solaris (on E 10000 etc.)
• Linux
Small Enterprise & Department Servers
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Windows NT/2000 – 40%
Linux – 27%
Netware – 17%
Unix – all versions – 14%
Hardware & O/S have to be evaluated together
• Winows NT and 2000 could display different
charcteristics on the same server depending on
implementations
• Windows NT/2000 only on Intel chips. Linux now
a competitor.
• Unix generally on RISC chips but many different
flavours
Scalability
• As demand on the server increases, how can
it be upgraded to handle the increased load?
• Main components are –
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Processor speed
Number of processors
Memory size and access speed
Data storage capacity and speed
Constraints on scalability
• Operating system support
• Number of processors permitted by the
architecture (e.g. Compaq DL580 has max of 4, Sun
E10000 has max of 64)
• Memory access often limits effective
utilisation of processors – increase in
throughput is not linear
Number and power of processors
• A key issue in scalability
• Sun’s Solaris OS can now support up to 128 but hardware
architecture of Sun E10000 has 64 processor limit
• Windows NT/2000 now supports up to 32 processors and
64GB of memory.
Originally supported 8 processors.
• New IA64 processor and Windows/IA architecture will
address 32 bit architecture limitations.
• IA64 architecture will put performance as well as price
pressure on the Unix/RISC based systems – within 2/3 years
Windows, Linux and 64 Bit Architecture
• 64 bit not designed to improve performance of 32 bit code
• Hence, code has to be written to take advantage of it. Linux
and windows have created the OS code. Linux ahead.
• 64 bit applications may be the limiting software factor.
• Major hardware limitation is probably now the PCI bus that
connects the processors and memory to storage and
controllers and expansion cards.
• Infiniband - 2.5G+ bytes/sec IO data transfer addresses this.
This technology is likely to become the data centre
interconnect technology for Intel based severs
Infiniband
• InfiniBand Technology will be used to connect servers
with remote storage and networking devices, and
other servers.
• It will also be used inside servers for inter-processor
communication (IPC) in parallel clusters.
Infiniband Architecture
Infiniband Architecture
Scalability and Multi processor servers
• Usually under the control of the one copy of the
operating system
• But some high end machines (Sun E10000) have
independent domains with each domain having its
own copy of the operating system. Like two or
more independent machines in the one box.
Server processor architectures
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Single processor
Symmetric multi-processor – SMP – shared bus
Symmetric multi-processor – SMP – cross bar
Non Uniform Memory Access (NUMA)
Clusters
SMP – Shared bus
CPU
CPU
Memory
pool
CPU
I/O
CPU
Compaq DL580
SMP – shared bus is the most common
• With Shared Bus – TPC benchmarks show that often
manufacturers get best performance at around
50% of maximum number of processors
Performance
15
10
Performance
5
19
16
13
10
7
4
1
0
SMP – Cross bar
CPU
CPU
CPU
CPU
Non Uniform Memory Access
CPU
Memory
CPU
CPU
CPU
I/O
CPU
I/O
CPU
Interface
CPU
Memory
Interface
CPU
Cross Bar
HP Super Dome & Sun E10000
Clusters
• Share nothing - Failover
• Share disk – requires distributed locking
• Share everything – slower than the bus of an SMP machine
LAN
High speed
Interconnect
Clustering gives
• Scalability – workload can be distributed
• Availability – when one goes down the
others take over
• System management – managed as a single
resource – particularly disk
Disk performance
• Capacity continues to double each year
• Speed made up of three elements
– Rotational latency
– Seek time
– Transfer rate
Storage architectures
• Two emerging storage architectures
– SAN – Storage Area Network
– NAS – Network Attached Storage
• SAN more closely coupled with servers
• NAS network orientated – higher latency
• High performance, large capacity, high availability,
data protection, management and back-up
Network Attached Storage
WEB
Application
Database
NAS Server
Storage Area Networks
WEB
Application
Database
File Server
Fibre channel