SVN User Forum David Asbury Alvaro Gonzalez Alvarez Pawel Kacper Zembrzuski 16 April 2010
Agenda for Today SVN User Forum • Welcome • CERN IT Reorganisation • SVN Client Versions • Status of Service, Migration to SVN • Current Efforts • Performance • Questions
CERN IT Reorganisation SVN User Forum • Jan 2010, most IT groups changed • CVS & SVN now in IT/PES group • Product and Engineering Support • Previous experts now in DB group • CVS & SVN now 3 people • David 80%, Alvaro 80%, Pawel 100% • 2 people after September 2010
SVN Client Versions SVN User Forum • SVN Server version is 1.5 • SVN client on lxplus is 1.4 (ok with server) • SLC4 has client 1.4.4, SLC5 has 1.4.2 - ok • Problem when use later major client version then return to lxplus • Want lxplus version = SVN server version • Must still be careful with versions elsewhere
Incidents and Support SVN User Forum • March 2010: adding new SVN server • Unexpected reordering of CDB templates • Selected by load balancing, but login failed • Full support during CERN working hours • Best-efforts basis outside this
Status of the Service SVN User Forum • Projects: CVS ~300, SVN ~450 • Want to end LCGCVS by end 2010 • Difficult to support, several disadvantages • Much work to move CVS to SLC5 • SVN has many small projects • More efficient for performance, management • TRAC uses NAS disk system (DB group)
CVS Projects SVN User Forum
SVN Projects SVN User Forum
Current Efforts SVN User Forum • Handling daily problems and questions • Performance studies - important • More servers on SVN for performance • Added 3 more servers, already better • Move CVS to SLC5 if not stopped (major) • TRAC plugins being tested • https://twiki.cern.ch/twiki/bin/viewauth/DESgroup/SVNFeatureRequest • Try to get Helpdesk to handle more queries • Very limited manpower for clients!
Performance: CVS v SVN SVN User Forum • SVN is the future, so effort will be there • Want redundancy so AFS is an advantage • LCGCVS uses local disks • CVS slow as it writes lock files into the directory at check-out • SVN writes into a lower directory • So SVN benefits much more than CVS from load-sharing across multiple servers • SVN also offers repository protection
Redundant Server Model SVN User Forum
Performance Studies (1) SVN User Forum • Most daily activity happens 2200 to ~0100 • Looking at whole chain from file system to client • AFS volume placement, splitting • Network • CVS/SVN server • memory, • disk setup, • AFS cache configuration
Performance Studies (2) SVN User Forum • Tests checking-out AFS volume on SSD • Local disks in LCGCVS: ~22 mins • AFS volume on SSD: ~31 mins • AFS volume on normal disk: ~40 mins • Impact on which machines to retire soon • Must retire some CVS servers soon (warranty) • Impact on new machine configurations
Suggestions and Questions SVN User Forum • Email to firstname.lastname@example.org • Don’t expect instant replies!