[En-Nut-Discussion] Fwd: SourceForge.net: CVS service offering changes

[Harald Kipp]

>From: "SourceForge.net Team" <noreply at sourceforge.net>
>Subject: SUBJECT: SourceForge.net: CVS service offering changes
>Date: Thu, 11 May 2006 16:41:17 -0700 (PDT)
>
>Greetings,
>
>You are receiving this mail because you are a project admin for
>a SourceForge.net-hosted project. One of our primary services,
>CVS, suffered a series of interrelated, critical hardware failures
>in recent weeks. We understand how frustrating this CVS outage
>must be to you and your users; however, our top priority remains
>preservation of the integrity of your data.
>
>The series of CVS hardware failures prompted us to expedite the
>deployment of planed improvements to our CVS infrastructure,
>drawing upon much of the knowledge that we gained from our
>Subversion deployment. Our improved CVS service architecture,
>which we plan to deploy tomorrow afternoon (2006-05-12), will
>offer greater performance and stability and will eliminate several
>single points of failure.
>
>The Site Status page (https://www.sf.net/docs/A04) will be
>updated as soon as the new infrastructure is rolled out. In the
>interim, please read the important information provided below
>to learn about how these changes will affect your project.
>
>
>Summary of changes, effective 2006-05-12:
>
>
>1. Hostname for CVS service
>
>Old: cvs.sourceforge.net
>
>New: PROJECT_UNIX_NAME.cvs.sourceforge.net
>
>This change will require new working copies to be checked out of all
>repositories (so control files in the working copy will point to the
>right place). We will be updating the instructions we supply, but
>instructions that your team has written within documentation, etc. will
>need to be updated.
>
>cvs -d:pserver:anonymous at cvs.sourceforge.net:/cvsroot/gaim co gaim
>
>would be changed to
>
>cvs -d:pserver:anonymous at gaim.cvs.sourceforge.net:/cvsroot/gaim co gaim
>
>
>
>2. ViewCVS
>
>We are moving from ViewCVS to its successor, ViewVC. ViewVC is
>currently in use for our Subversion service.
>
>
>
>3. Sync delay
>
>Old: CVS pserver, tarballs and ViewCVS provided against a separate
>server which is a minimum of three hours behind developer CVS.
>
>New: ViewVC will be provided against developer CVS (it will be current).
>CVS pserver will be provided against a secondary server (not developer
>server) with a maximum expected delay of two hours.
>
>Follow-up work is planned (this infrastructure takes us 80% of the way)
>to essentially eliminate the sync delay.
>
>
>
>4. Read-only rsync service
>
>As a new service offering, we are now providing read-only rsync access
>against developer CVS. This allows projects to efficiently make
>on-demand backups of their entire CVS repository.
>
>All projects should be making regular backups of their CVS repository
>contents using this service.
>
>
>
>5. Nightly tarball service
>
>Nightly tarball service is being dropped in lieu of read-only rsync
>service. Projects which currently depend on nightly tarballs for
>repository backups will need to begin using rsync to make a backup copy
>of their repository contents.
>
>We see this as a major functional improvement. For a number of reasons,
>tarballs have fallen out of sync with the data in the repository at
>times in the past few years. Tarballs required a substantial amount of
>additional disk, and I/O to generate. The move to read-only rsync
>allows backups to be produced on-demand, with an update frequency chosen
>by the project.
>
>
>
>6. Points of failure
>
>In the past, developer CVS service for all projects was provided from a
>single host. CVS pserver service was provided from individual backend
>heads based on a split of the data.
>
>Under our new design, developer CVS and most of our CVS-related services
>are provided from one of ten CVS hosts (count subject to increase with
>growth). Each host is independent, and makes a backup copy of the
>repository data of another host (which is used to provide the pserver
>CVS service).
>
>Failure of a single host will impact only the availability of data on
>that host. Since the data is split among a larger number of hosts, the
>size of data impacted by an individual host outage is substantially
>smaller, and the time required for us to restore service will be
>substantially shorter.
>
>This rapid architecture change has been made possible specifically using
>the research we performed for our recent launch of Subversion service.
>We've applied our best practices, produced a substantial amount of
>internal documentation, and kept an eye toward maintainability.
>This effort has allowed us to deploy this new architecture quickly
>once hardware was received, and will permit us to quickly scale
>this service horizontally as growth and demand requires.
>
>
>
>Many other minor improvements have also been made to improve the service
>offering and make it less trouble-prone. The most important of which are
>listed above. For a full description of the new service offering, and
>for information on how to use the services described above, please refer
>to the site documentation for the CVS service after the service has been
>launched: https://www.sf.net/docs/E04
>
>
>Thank you,
>
>The SourceForge.net Team
>
>.