Evolution of the CERN printing service

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Evolution of the CERN printing service
Ignacio Reguero, Sam Lown October 2002
PS/Unix Infrastructure Section IT Division, CERN
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Outline

• Description of the Printing System
• Before, After
• Upgrade Process
• Hardware, Software
• Manageability
• Configuration
• Accounting
• The Future

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System Description

• CERN Print service
• 1180 network printers
• 1400 total queues
• Including trays and remote printers
• Statistics based on current System
• 17,000 jobs per day
• 14Gb spooled per day
• 70,000 to 100,000 Pages per day

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System Description Before
Web Server
Accounting Summary
Printer Server Back-end
PRINT3
PRINT1
PRINT2
DNS Server
Printer Name
Server IP
Clients
MS Windows
Unix/Linux
AppleTalk
TCP/IP
LPR (RFC1179)
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System Description Before
Apsfilter
LPRng
Convert to PostScript
APS config for Printer
Determine CommProg
if (model /hp2500/) if (opt_Q /A3/)
opt_Z a3,inupper ...... .....
Determine Model
Determine Output Filter Options
Add Options to Output Filter
commprog commprog. -Z.opt_Z
Papif
CTH-ifhp
Phaserif
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System Description Before

• Characteristics
• Centralised
• All clients talk to the same server rather than
  each client trying to access the printer directly
  (No collisions)
• High Reliability
• No single points of failure
• Unified
• All clients access servers using standard
  protocols

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System Description Before

• Problems
• Limited Tray Support
• Printer trays are hard-programmed
• Lacks new LPRng IFHP features
• Limited Scaleability
• Scripts for each new printer must be run on EACH
  serveri.e. More Servers More Work
• De-Synchronisation
• Each server may contain different configurations
• Limited Accounting

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System Description After
Web Server
DBMS (oracle)
Accounting
Accounting
Configuration
Configuration
Printer -gt Server Mappings
Printer Server Back-end
PRINT1
PRINT2
PRINT n
DNS Server
...
Printer Name
Server IP
Clients
MS Windows
Unix/Linux
AppleTalk
TCP/IP
LPR (RFC1179)
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System Description After
Apsfilter
LPRng
Convert to PostScript
APS config for Printer
Determine CommProg
commprog . -Tmodelhp2500cm opt_z .
inupper,a4
Add Model
Add Tray Options (opt_z)
Add Options to Output Filter
commprog commprog. -Z.opt_Z
Netatalk
LPRng IFHP
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System Description After

• Characteristics
• Centralised Configuration
• Always synchronised
• New IFHP features used
• Better Tray Support
• Improved accounting
• Individual jobs can be recorded rather than a
  summary
• Improved Scaleability
• More servers can be added with less work and less
  synchronisation problems

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The Upgrade Process

• Hardware and Software Upgrades

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The Upgrade Hardware

• Previous System
• 3 Machines
• Pentium Pro 200Mhz
• 199.07 BogoMips
• 256Mb RAM
• Hard Disk - SCSI 9.1Gb
• Fast Ethernet 10/100Base-T Network

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The Upgrade Hardware

• Replacement System
• 3 Machines
• Dual Pentium 3 800Mhz
• 3185.04 Total BogoMips
• 512Mb RAM
• Hard Disk IDE 40Gb
• Fast Ethernet 10/100Base-T Network
• SCSI bus available (for CDR)

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The Upgrade Software

• RedHat 5.0 RedHat 7.2.1 CERN
• Kernel 2.4.x (from 2.0.32!)
• Perl 5.6
• Using Locally Compiled Software for Printing
• LPRng, IFHP, netatalk

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The Upgrade Software

• LPRng 3.5.2 3.8.13
• General Bug/Performance fixes
• CTI-ifhp 2.2.8 LPRng-IFHP 3.5.10
• Uses ifhp.conf for printer control commands
• No 'hard-coded' PostScript/PCL
• Vastly improved printer support (replaces
  Phaserif)
• Vastly improved Tray Support
• Easily modified
• Improved Accounting

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The Upgrade Software

• CAP 6.0 Netatalk 1.5.3.1
• CAP is deprecated!
• No support
• Required too much work to recompile on new system
• Netatalk now provides superior performance
• Wrapper Required for compatibility
• Maps original papif options to new pap command
• Plug-in replacement for Apsfilter
• Accounting improvements
• Adds some functions only done by CAP (trays
  selection)

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Manageability

• How to manage 1100 printers....

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The Database
SERVER
PRINTER
PRINTER TYPE
Configuration
TYPE TRAY
Accounting
PRINTOUT
USER
HOST
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The Database

• All Database Functions Stored in Single Module
• PrintMan.pm (PrintMan Printer Manager)
• General Purpose Module
• Hides SQL code
• Basic functions for each table
• Add, Update, List, Get, Delete
• Job entry functions optimised for efficiency
• Database access minimised by caching data
• Provides Check functions for data entry
• Simplifies programming of user interfaces

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Manageability

• Database Centric Configuration
• Configuration files
• Generated automatically
• Easily modified
• Synchronised on all systems
• Support for SQL data extraction
• Generated Files
• /etc/printcap Standard LPR printcap
• /etc/cap.printers Printer name lookup file for
  AppleTalk
• apsfilter/conf/ltPrinterNamegt ApsFilter config
  folder
• NamedFile DNS lookup Each printer points to
  server

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Manageability

• Database Accounting
• Each Job Recorded
• Including size, pages, and date
• Job records cached locally
• Jobs collated and inserted at end of day
• Support for LARGE Tables
• 400Mb data required per year
• Statistical Report Generation
• Fast, Dynamic
• Order by user, date, jobs, pages, hosts, etc. ....

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The Future

• High Availability
• Server monitoring
• Automated redirection (alter DNS, slow)
• Server Load Balancing .. ?
• Difficult
• Simple re-routing of TCP pipe does not
  work(Linux Virtual Server Project)
• Printer spool dir must be on same server
• Possible?
• Load Balancer forwards to correct server (DBMS
  helps)

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Questions

• ?