gitblit/src/site/setup_scaling.mkd

## Scaling Gitblit

My experience with scaling Gitblit to be very large is from interacting with those who do run very large Gitblit or Gerrit installs.

### Configuring Big JGit Servers

-Xmx8g # gobs of JVM heap

    # for `jgit daemon` or gerrit.config
    [core]
        packedGitLimit = 4g # around 50% of JVM heap
        packedGitOpenFiles = 8192 # don't forget to configure ulimit
        streamFileThreshold = 2047m # avoids pathological inflate
        deltaBaseCacheLimit = 50m

    # applies to `jgit gc`
    [pack]
        bigFileThreshold = 20m # don't delta compress big binaries
        indexVersion = 2 # use index v2

-- Shawn Pearce, co-team lead on JGit @ Google ([slides](http://www.eclipsecon.org/2013/sites/eclipsecon.org.2013/files/Scaling%20Up%20JGit%20-%20EclipseCon%202013.pdf))

### How does these Gerrit settings apply to Gitblit?

Gerrit & Gitblit are both JGit-based servers.  They have similar configuration options.  Here are the relevant Gitblit settings:

    git.packedGitLimit = 4g
    git.packedGitOpenFiles = 8192
    git.streamFileTreshold = 2047m
    git.deltaBaseCacheLimit = 50m