Cyrus IMAP and MySQL mailboxes (Building load-balancing cluster)

[Simon Matter]

>> 2) Several people on this list have confirmed that they are running
>> cyrus-imapd clusters on shared storage (SAN) which works fine with a
>> cluster filesystem. That tells me that shared access to cyrus
>> databases
>> works fine as long as the filesystem used provides proper
>> locking, which
>> means in case of a cluster that the cluster filesystem has to
>> coordinate
>> locking among all cluster members. Isn't that the main reason
>> why those
>> filesystems exist?
>
> If it works, great. I haven't worked with this kind of cluster before,
> so I don't have any experience with it. What I said is that *database*
> locking is in the OS, not the filesystem, and as such the clustering
> software wouldn't actually work. As another post (by Janne) pointed
> out, if you avoid BDB then this isn't an issue because you would be
> using filesystem locking.

While I agree that avoiding berkeley DB is a good thing, are you really
sure that the cluster won't work with it? What is really different between
using berkeley or skiplist DB for the cluster? I'm also running without
BDB but I want to understand how berkeley databases are different to
skiplist databases in a cluster situation.

Regards,
Simon