Distributed SCM Repositories

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Distributed SCM Repositories

• Justin R. Erenkrantz
• ICS 280
• December 4th, 2002

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Subversion

• Compelling replacement for CVS
• Still has a centralized server model
• WebDAV is the core transport protocol
• How can we distribute the repositories?
• Geographical dispersion
• Offline access

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Internal or External Replication

• Subversion internally uses Berkeley DB
• Has primitive notion of replication
• Can we use its replication?
• Another strategy is leverage WebDAV
• Intercept calls to the original server
• Proxies are well-defined by HTTP
• Virtually ignored by WebDAV

4
Proposed Solution

• Combination of two approaches
• Master pushes out database changes
• Requires registration of slave servers
• Slaves handle all operations
• Read-only slaves
• Handles read on its own
• Transparently divert write to master