[jr3] support transaction log

[Guo Du <on...@duguo.com>]

I am thinking of database transaction log in jackrrabbit. The log
could be replayed to any point of time.
http://en.wikipedia.org/wiki/Transaction_log

It could be used as efficient backup/recovery/replication scenario.
It's different from current cluster configuration which share some
storage among the nodes.

-Guo

Re: [jr3] support transaction log

[Guo Du <mr...@gmail.com>]

On Thu, Mar 4, 2010 at 11:39 AM, Thomas Müller <th...@day.com> wrote:
> It may slow down writes around 50%. I think it should be an "optional"
> feature (some storage backends may not support it at all, and there
> should be a way to disable / enable it for those backends that can
> support it). I think we should support writing our own transaction log
> even when using relational databases, but I guess it should be
> possible to switch that off.

Good point. I don't expect it will be in micro-kernel. It will fall
into pluggable before-commit event handling, but it should be
transactional, otherwise, the corrupted log could be useless.

It shouldn't related to backend storage, the log should record what
happen to repository, doesn't care the persistent manager.



-Guo

Re: [jr3] support transaction log

[Thomas Müller <th...@day.com>]

Hi,

It may slow down writes around 50%. I think it should be an "optional"
feature (some storage backends may not support it at all, and there
should be a way to disable / enable it for those backends that can
support it). I think we should support writing our own transaction log
even when using relational databases, but I guess it should be
possible to switch that off.

Regards,
Thomas