Subversion 1.7: Five Reasons to Migrate

The Apache Software Foundation have announced the general availability of 1.7; but how exactly will the new features in 1.7 affect the user? And why should you upgrade to version 1.7? Here are five good reasons, to make the leap to Subversion 1.7 today:

1) Completely Rewritten Working Copy Metadata System

In Subversion 1.7, the working copy metadata system has been completely overhauled. For the user, this means:

  • An immediate performance boost. All the metadata for the whole working copy is now stored in a single datastore in the root of the working copy, so Subversion operations no longer have to walk the entire directory tree to gather all the necessary information about a working copy.
  • Many small fixes (e.g WC-NG uses a generated index key to avoid case-sensitive file name issues) that together add up to a much more robust metadata storage system.
  • Get ready for the future! The original WC library had grown so complex, that introducing new features was becoming a real effort. WC-NG paves the way for new features, beyond 1.7.

2) Improved HTTP Protocol

For 1.7, the Subversion team decided to drop DeltaV in favor of a new HTTP protocol variant, ‘HTTPv2.’ This has a number of benefits for the Subversion user:

  • Removes the overheads associated with DeltaV (e.g additional port find requests in the Apache log file of a Subversion server.)
  • Fewer client-server round trips per request means enhanced performance between Subversion clients and the server.
  • Reduced server load (due to fewer requests to log and fewer accesses to the repositories.)

3) Get Control Over Your Cache

Version 1.6 introduced an in-memory caching system, but many users experienced problems with an increasing amount of memory being allocated to the cache. Subversion 1.7 gives you greater control over your cache:

  • Functionality for controlling how much memory is used by the cache, to prevent the amount of memory allocated to the caching growing out of control.
  • New caching structure and new code that has a better behaviour, regarding memory usage.

4) Configurable Data Compression Rate

Users with a high enough bandwidth can end up spending more time on the compression and decompression of data, than they gain by sending compressed data. Subversion 1.7 allows the user to configure the data compression rate; by sending uncompressed data on a high bandwidth, the server has a lower load and can respond faster.

5) New ‘svnrdump’ Remote Dumpfile Tool

Subversion 1.7 gives users the ability to replicate the functionality of svnadmin dump and svnadmin load on remote repositories. No administrator access to the source or target repository required!

Certified open source Apache Subversion 1.7 binaries can be downloaded from our website or, alternatively both Subversion 1.6 and 1.7 are available in our free, open ALM platform, uberSVN.