MV Discovery
A cruise ship is a hotel afloat on the high seas. It has passenger cabins and restaurants, bars, fitness rooms, swimming pools, shops and night clubs. Passengers have to be checked on and off the ship. Cabins have to be cleaned, facilities maintained and repaired. A computer system is needed to manage this, to monitor passenger movements and ensure the ship doesn’t sail with passengers left behind in port.
The system must withstand the motion of the waves, which can be severe. It must cope with the vessel’s electricity generation, less clean than the National Grid, with spikes and power surges. Cables that run below the waterline must not compromise the integrity of waterproof compartments. Because the ship is generally many miles off shore the system must be extremely reliable, robust and fault-tolerant. If it fails then drinks cannot be sold, passengers will not be identified as they use the facilities or embark or disembark and a myriad other activities would be compromised. In effect it is in a hostile environment and, at the same time, mission-critical.
MV Discovery
In November 2000, Discovery Cruises was refitting the MV Discovery as a cruise vessel and bringing it up to current standards. It needed an IT network to provide passenger management and safety functions and cover all non-navigational and non-bridge requirements. Various suppliers were contacted and Terry Doherty, CEO of Doherty Associates, visited the ship in its Scaramanga dry dock in Greece to assess the situation. He created a draft blue print and outline costing in December 2002.
The design was based around a rack of five HP ProLiant servers, placed in the centre of the ship to minimise movement, with RAID disk arrays connected via a 100BaseT network to 52 HP EVO workstations, one HP Laptop and eleven Epson MR800 point-of-sale (POS) devices. Power supplies and cooling equipment are duplicated. There are 64 users on board in total. The main server is for file and print, database and messaging work. There is a backup server for it, and a remote installation server (RIS) storing ready-prepared system image builds for the other servers and workstations.
Server overall health status as on the monitoring console at the Chiswick office
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All servers, workstations and POS terminals run Microsoft Windows XP Professional with Terminal Services options. Microsoft Exchange Server Enterprise Edition is used for messaging and collaboration facilities. SQL Server 2000 is the database for the line of business applications. ISA Server 2000 is used to provide firewall, proxy and VPN services for shipto-shore links. Cat 5 UTP cabling is used with HP ProCurve network switches.
Server processor utilisation as on our monitoring console in Chiswick
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If A Fault Occurs
When status changes occur SNMP traps cause e-mail messages to be sent to Chiswick where on-screen displays track system status. A greenyellow-red traffic light warning system operates along with emailed alerts so that faults can be detected and fixed. For example, a virus may be detected and quarantined.
If a PC or POS terminal fails then Chiswick is notified. Ship-board personnel replace the failed unit with a spare and it is connected to the network and to power. Doherty Associates’ monitoring staff install the new system’s software image from the on-board RIS server.
The RAID arrays mean that two out of the five disks in the array can fail before any data is lost. Each disk in the RAID array is in a named slot and the backup server has an identical but unpopulated RAID array with named disk slots. Were the main server itself to fail because, for example, its motherboard failed, then ship personnel move the disks from their slots on the main server’s RAID array to the backup server’s array, under the telephone supervision of the Chiswick staff.
When this is done the backup server has a pre-prepared system image installed and started. The changeover process is simple to execute, robust and takes little time. A clustered solution could have automatic failover but the complexity would require a great deal more expense, tens of thousands of pounds, for both hardware and software, with little or no business benefit for the ship.
Terminal Services is the key to the remote monitoring and allied cost-savings. Terry Doherty says, “Discovery Cruises’ Swiss HQ staff can connect to the ship remotely via Terminal Services and run a revenue report as though they were on-board. A ship-based accountant can connect to the Swiss HQ, again via Terminal Services, to update a general ledger in the office there. ”