cern it department ch-1211 genève 23 switzerland pes svn user forum david asbury alvaro gonzalez...

CERN IT DepartmentCH-1211 Genève 23

Switzerlandwww.cern.ch/it

PES

SVN User ForumDavid Asbury

Alvaro Gonzalez AlvarezPawel Kacper Zembrzuski

16 April 2010



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



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




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 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




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




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)




PES CVS Projects




PES SVN Projects




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

• https://twiki.cern.ch/twiki/bin/viewauth/DESgroup/SVNFeatureRequest

Try to get Helpdesk to handle more queries Very limited manpower for clients!




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




PES Redundant Server Model




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




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




PES Suggestions and Questions

Email to [email protected] Don’t expect instant replies!


cern it department ch-1211 genève 23 switzerland pes svn user forum david asbury alvaro gonzalez...

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