Scaling up Cambridge University’s email service

4.1. Two-phase expunge
4.2.2. Replication protocol
5.1. Cyrus compatibility
6.2. Shared mailboxes
6.5. Wide-area distribution and high availability

Errata

The version of the paper published in the proceedings of the UKUUG LISA Winter Conference has a number of errors and ommissions detailed below. These have been corrected in the on-line copy.

4.1. Two-phase expunge

Message files aren’t actually moved. The expunged messages shadow folder is just another set of index files in the same directory. This is another reason that this feature helps performance; only the index files need to be changed during an expunge.

4.2.2. Replication protocol

The description of the SEEN action is missing. This updates the user’s database of which messages in the given folder have been seen. In case of problems it falls back to MAILBOX.

5.1. Cyrus compatibility

Typo in paragraph 5: ‘‘behaves’’ should be ‘‘behave’’.

6.2. Shared mailboxes

The replication engine’s handling of SEEN actions needs some work since it has some built-in assumptions that break when fully general shared mailboxes are permitted.

6.5. Wide-area distribution and high availability

STOMITH is more usually called STONITH (‘‘node’’ rather than ‘‘machine’’).