1. WhiteCross Systems
Wx9020 Database Server
WX System Overview

2. System Overview Principles of Server Operation The WX9020 Server
How is data stored?
How do users get access?
The WX9020 Server
What is behind the doors?
Main components of rack
Rack communications

3. System Overview The WX9000CP Thermal management Power & batteries
The Daemon
Thermal management
Power & batteries
Monitoring server operations
The next stage...

4. Principles of Server Operation
The WX9020 Server is designed to be a high-capacity, high workload database server for use in data centres
Large datasets are loaded down on to the disks fitted to the server from a source elsewhere on the network
Parallel processing of large datasets gives phenomenal processing speeds
User access to the server is via a standard network connection

5. Data in Memory (RAM)
To get the fastest processing performance, the user tables are copied from the disks and shared out among the processors which go to make up the processing network within the WX9020 server

6. The User Environment Users WX9000CP Modem Data source(s)
System Administrator/DBA

7. The WX9020 Server
Redundancy built into hardware - for reliability and availability
Power supplies (3)
Battery back-up
Temperature sensors (10)
Fans (4)
Software monitoring of hardware components (fan speed, temp, power supplies etc.)

8. Opening the Front Door Acrylic panels assist in thermal management
Access to power supplies & batteries restricted
System Controller Subrack
Two configurable Subracks
Fan trays
Upper Fan Tray
Lower Fan Tray
Power Supply Units

9. Opening the Rear Door Acrylic panels assist in thermal management
Access to power controls restricted
Three configurable Subracks
Fan trays
Power ON/OFF controls
External connections to power and WX9000CP
External connections
Upper Fan Tray
Lower Fan Tray
AC Power Indicators
and switches

10. Side View Front Rear Side panels can be easily removed
Removal not necessary for normal maintenance
System Controller
Cooling Fans
Subrack
Subrack
Front
Subrack
Subrack
Rear
Subrack
Subrack
Power subsystem
Cooling Fans
Power
Switch

11. Configuring the WX9020 Four HCDMs = 8 x 2G IBM disks
Choose the hardware configuration that most suits current needs - expand as needs grow
Each rack must contain a System Controller Subrack
Hardware is configurable e.g. the BT system comprises:
1 Disk Subrack (below System Controller Subrack)
Four HCDMs = 8 x 2G IBM disks
16 Processor cards
9 in Processor Subrack (rear door, upper Subrack)
4 in System Controller Subrack
3 in Disk Subrack
WX9000CP connects via PE card in the Disk Subrack

12. WX9020 Subracks Subracks can be: System Controller Processor Subracks
System Management
Processor Subracks
Containing Processor cards
Disk Subracks
Containing HCDMs & PS cards, Processor cards and PE card

13. WX9020 Thermal Management
Rack contains two pairs of fans numbered 0,1,2,3
Rack contains ten temperature sensors numbered 0 - 9
Air is pulled through in two “chimneys” over contents of cabinet
Air inlet filter in rear door (bottom)
Air outlet vents in rear door (top)
Monitor hardware as part of regular maintenance

14. The System Controller Subrack
Responsible for system management
Booting up & shutting down
Checks for system failure
Communicates with outside world via WX9000CP
Handles front panel messages
Handles diagnostics
Manages software upgrade

15. The System Controller Subrack (2)
A dual rack containing several different cards:
System Controller cards
Processor cards
HSL cards
Front Panels
Key switches
LCD displays
Everything doubled for failure resilience

16. Layout of the System Controller Subrack
A fault-resilient, dual ring System Controller Subrack contains:
2 System Controller cards
4 High Speed Link cards
4 Processor cards
2 Front panels LCD displays

17. Layout of the System Controller Subrack

18. How do Subracks Communicate?
All communication inside the rack is via fibre optics
All data and control signals are passed along fibres
This gives speed and bandwidth
125 Mbits/sec
All Subracks are interlinked in a fibre optic ring
Second ring gives added protection against component failure
High Speed Link (HSL) cards in each Subrack act as links in this chain

19. Rack/Subrack Communications
The main communications ring is handled by the Active Controller (A ring)
The secondary communications ring is handled by the Passive Controller (B ring)
The HSL cards provide a virtual link between system components

20. The Processor Subrack
Must contain at least one Processor card and one HSL card
A dual ring WX9020 must contain:
2 Processor cards
2 High Speed Link cards
Fully configured holds 19 Processor cards

21. Layout of the Processor Subrack

22. Processor Card Small board (233mm x 280mm) contains:
Front edge
Small board (233mm x 280mm) contains:
LED status lights
6 transputers - INMOS T4 (60 MIPS)
96 Mbytes local RAM (6x16Mb)
Error correcting DRAM
DC - DC Voltage converters
Components are surface- mounted (on both sides of the board) for higher reliability and density.

23. The Disk Subrack
Must contain at least two HCDMs, two Processor cards and a HSL card
A fully-configured, dual ring WX9020 contains:
4 HCDMs
4 Processor cards
or 3 Processor cards PE card
2 High Speed Link cards

24. Layout of the Disk Subrack
Note: slots 4 and 5 can contain either a Processor card or a PE card

25. The High Capacity Disk Module
Contains two disks of 2 Gbytes each
Has two fully-independent SCSI 2 disk controllers
Each controller holds its own processor and 16 Mbytes of RAM
No internal cabling - designed to be hot-pluggable (R4)

26. Data on Disk - RAID 3
Given a cluster of 4 disks, 3 are designated data disks and 1 is designated the parity (or XOR) disk

27. Disk Recreation
At boot-up server will check data and parity disks for consistency
Any inconsistency recorded in error log and the disk(s) recreated automatically
Boot-up operations are configurable
Recreation can lengthen the time taken to boot-up
Auto disk recreate can be done manually

28. External Connectivity
An interface is required to connect the WX9000 server to the LAN so that it can communicate with clients on the same (or different) network
WCS does this via the WX9000CP communications processor
Provides modem connection
CP is a SPARC-based workstation.
Choice of connectivity options.
CP channels the SQL queries, results and data.
Clients
LAN
Server CP

29. The RDA Daemon
The Daemon provides the communications software to control the connection between the WX9020 server and the network
WX Server
LAN CP
Client PC

30. Power Controls Power is switched on/off via a three phase contactor
Controlled by single pole breaker
The breaker contains a voltage-driven trip
If auto shutdown enabled, the system can trip the breaker and so switch off when required
Switched power output from the three phase contactor is distributed to power supplies and battery charging circuits

31. DC Power Three Farnell PSUs (with in-built redundancy)
Generate internal 56v rail
AC to each PSU protected by 20amp circuit breaker
Allows live changes
56v negative rail fused with 63amp fuse
56v positive fed via diodes to common bus bar
Positive rail tied to Earth

32. Batteries - Overview
In the event of a complete power failure, batteries deliver +48v
Normally draw no current from the system-wide 56v rail
Batteries connected in the same way as PSUs
Negative rail fused with 120amp fuse
Positive rail fed via diode
Contactor on the +ve rail for disconnect when required
Trickle-charge feeds to batteries to maintain charge level
Battery life expectancy = 4 years

33. Batteries - Charging
Power supply on Power Monitor card produces 55.2v for trickle-charge
Powered directly from the AC supply
When batteries not fully charged, circuitry switches to constant-current charging to deliver 2amps
WX9020 has in-built circuitry to derive 50v for this charging

34. Monitoring Server Operations
Useful messages on front panel display:
During normal running
During re-boot sequence
Indicator lights fitted to each card
Running / warning lights fitted to HCDMs
In software:
Accessing system tables directly using SQL
Using WCS front end tool e.g. SQL Console
From scripts

35. The Front Panel Two front panels are fitted to the WX9020
In a dual ring system both front panels are connected and the LCD displays will indicate current status of server - one each for the A and B ring controllers
Three key switches:
Re-boot
Operation mode
SYS/RACK switch
RE-BOOT
SYS
AUX1
AUX2
RACK
EXT
INT
DEBUG 1 2 3

36. The Front Panel Two-line, liquid-crystal textual display
Reboot key switch
RE-BOOT
SYS
AUX1
AUX2
RACK
EXT
INT
DEBUG 1 2 3
SYS/RACK switch (only relevant in a multi-rack system)
Disk activity LEDs
Key switch for mode of operation

37. The Front Panel - Key Switches
Re-boot key
Used to re-boot server
SYS/RACK switch
Always set to SYS in a single cabinet WX9020
Mode key - used to determine “bootmode” or mode of operation
‘INT’ernal mode is the normal mode of operation
DEBUG mode is for diagnostics & remote access
‘EXT’ernal mode is used for installing new versions of software

38. The LCD Display Shows useful information about status of server: P 6:
Software version number always displayed
Pages of information are displayed in continuous cycle
Updates every ten seconds
P 6: V
Running
Procs:
100
Disks: 8

39. The WhiteCross HelpDesk

40. The White Cross Help Desk
Based in Bracknell HQ and available during UK office hours ( )
Contact by phone, fax,

41. Contacting the Help Desk
Contact the Help Desk (& Reception) on:
Telephone:
Facsimile:
Contact the Help Desk directly on:
…and soon on the world wide web too.

42. Questions?