CERN IT Department CH-1211 Genève 23 Switzerland PES SVN User Forum David Asbury Alvaro Gonzalez Alvarez Pawel Kacper Zembrzuski 16 April 2010

CERN IT Department CH-1211 Genève 23 Switzerland PES Agenda for Today  Welcome  CERN IT Reorganisation  SVN Client Versions  Status of Service, Migration to SVN  Current Efforts  Performance  Questions SVN User Forum 216 April 2010

CERN IT Department CH-1211 Genève 23 Switzerland PES CERN IT Reorganisation  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 User Forum 316 April 2010

CERN IT Department CH-1211 Genève 23 Switzerland PES SVN Client Versions  SVN Server version is 1.5  SVN client on lxplus is 1.4 (ok with server) SLC4 has client 1.4.4, SLC5 has 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 SVN User Forum 416 April 2010

CERN IT Department CH-1211 Genève 23 Switzerland PES Incidents and Support  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 SVN User Forum 516 April 2010

CERN IT Department CH-1211 Genève 23 Switzerland PES Status of the Service  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) SVN User Forum 616 April 2010

CERN IT Department CH-1211 Genève 23 Switzerland PES CVS Projects SVN User Forum 716 April 2010

CERN IT Department CH-1211 Genève 23 Switzerland PES SVN Projects SVN User Forum 816 April 2010

CERN IT Department CH-1211 Genève 23 Switzerland PES Current Efforts  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 /SVNFeatureRequesthttps://twiki.cern.ch/twiki/bin/viewauth/DESgroup /SVNFeatureRequest  Try to get Helpdesk to handle more queries  Very limited manpower for clients! SVN User Forum 916 April 2010

CERN IT Department CH-1211 Genève 23 Switzerland PES Performance: CVS v SVN  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 SVN User Forum 1016 April 2010

CERN IT Department CH-1211 Genève 23 Switzerland PES Redundant Server Model SVN User Forum 1116 April 2010

CERN IT Department CH-1211 Genève 23 Switzerland PES Performance Studies (1)  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 SVN User Forum 1216 April 2010

CERN IT Department CH-1211 Genève 23 Switzerland PES Performance Studies (2)  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 SVN User Forum 1316 April 2010

CERN IT Department CH-1211 Genève 23 Switzerland PES Suggestions and Questions  to  Don’t expect instant replies! SVN User Forum 1416 April 2010