CERN IT DepartmentCH-1211 Genève 23

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PES

SVN User ForumDavid Asbury

Alvaro Gonzalez AlvarezPawel Kacper Zembrzuski

16 April 2010

CERN IT DepartmentCH-1211 Genève 23

Switzerlandwww.cern.ch/it

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 DepartmentCH-1211 Genève 23

Switzerlandwww.cern.ch/it

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 DepartmentCH-1211 Genève 23

Switzerlandwww.cern.ch/it

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

SVN User Forum 416 April 2010

CERN IT DepartmentCH-1211 Genève 23

Switzerlandwww.cern.ch/it

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

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Switzerlandwww.cern.ch/it

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 DepartmentCH-1211 Genève 23

Switzerlandwww.cern.ch/it

PES CVS Projects

SVN User Forum 716 April 2010

CERN IT DepartmentCH-1211 Genève 23

Switzerlandwww.cern.ch/it

PES SVN Projects

SVN User Forum 816 April 2010

CERN IT DepartmentCH-1211 Genève 23

Switzerlandwww.cern.ch/it

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!

SVN User Forum 916 April 2010

CERN IT DepartmentCH-1211 Genève 23

Switzerlandwww.cern.ch/it

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 DepartmentCH-1211 Genève 23

Switzerlandwww.cern.ch/it

PES Redundant Server Model

SVN User Forum 1116 April 2010

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Switzerlandwww.cern.ch/it

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 DepartmentCH-1211 Genève 23

Switzerlandwww.cern.ch/it

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 DepartmentCH-1211 Genève 23

Switzerlandwww.cern.ch/it

PES Suggestions and Questions

Email to svn.support@cern.ch Don’t expect instant replies!

SVN User Forum 1416 April 2010