Hey Martin sorry for taking so long to respond to you especially when you responded so quickly and thoroughly. More in line ...
On 9/21/07, Martin Alderson <[EMAIL PROTECTED]> wrote: > > Hi Alex, > > For my fairly limited use mitosis is performing very well. This is excellent news. I've slacked off a bit over the last few weeks but will try to get back > onto it soon. No worries me too. I keep context switching these days myself. For stable use there is still that critical issue where a change on the > same entry on multiple servers will lead to a permanently inconsistent > state. I'll make that my priority soon. Ok what I want to do is setup and environment soon and start trying to reproduce this as well as any other problems. This way I can work with you or at least help answer any questions you have while attacking this problem. I guess we can have intermediate states where the replicas are not in sync but they must converge over time so this is a critical issue. I'll try to help out as best as I can on this. I also recently came across a minor timeout issue which I think is a > problem in MINA. I'll investigate that more soon too. This is new to me but if you localize it I'm sure we can fix it. Aside from that there are niggling issues like replication of schema > changes. Yes this is something I am dreading. It's almost as if replicating a partition must force replicating the schema across that cluster but other clusters on different partitions will be all tied together for schema changes. This is why Microsoft decided to put schema into each partition for ADAM. Although painful we could do the same but I think we can work around this without one offs but it will shift the design a bit. Once these issues have been worked out I think we have a > stable replication system. Yep. There are some features that I guess we really need to get in for it to > actually be useful for the majority of users though. The main things > that come to mind are selective replication, encryption, schedules and > removing the dependency on Derby. Yes these are also my concerns especially encrypting the replication channel. We have some ideas that Ersin and I tossed around regarding all these issues. I guess we should start simple. First we should think about integrating the UUID capabilities which are part of mitosis into ApacheDS core so UUID is supported whether you turn on replication or not. Then from there I'd like to make the quartz scheduler a core service (not interceptor) that is accessible from the DirectoryService interface to be able to schedule anything. So moving these things up simplifies Mitosis a bit. Then it's reasonable to just move the replication log off of Derby into a custom store implementation based on JDBM. Eventually we'll need to expose this data via LDAP but we don't need to do it immediately. For now getting rid of the dep and having a clean store implementation is enough. I know you and Ersin are thinking about possible design changes although > to me those can be done incrementally later on as required. I doubt > that I will be a driving force behind these changes but am willing to > help. > Right I agree with you on the incremental changes. Don't sell yourself short the new design changes are things I think you can easily grok. Plus we're not moving fast with anything at the moment - we just have ideas. The problem has been where to dig in and start getting traction. I think we can do the things above in parallel with introducing design changes as well. Alex
