Hi Gustavo, There was some talk of startTransaction(), addTransaction(), commit() kind of api on the list.
Here is the link: http://www.mail-archive.com/zookeeper-dev@hadoop.apache.org/msg08317.html Mostly looked like this wasn¹t on our roadmap for short term, but definitely something to think about longer term. Thanks mahadev On 8/23/10 3:32 PM, "Gustavo Niemeyer" <gust...@niemeyer.net> wrote: >> So, we end up with something like this: >> >> A/B >> A/C/D-0 >> A/C/D-1 > > While people are thinking, let me ask this more explicitly: how hard > would it be to add multi-step atomic actions to Zookeeper? > > The interest is specifically to: > > 1) Avoid intermediate states to be persisted when the client creating > the state crashes > > 2) Avoid intermediate states to be seen while a coordination structure > is being put in place > > I understand that there are tricks which may be used to avoid some of > the related problems by dealing with locks, liveness nodes, and "side > services" which monitor and clean up the state, but it'd be fantastic > to have some internal support in Zookeeper to make these actions > simpler and less error prone. It feels like, given Zookeeper > guarantees, it shouldn't be too hard to extend the protocol to offer > some basic-level operation grouping (e.g. multi-create and > multi-delete, at least). > > Does that make sense? > > -- > Gustavo Niemeyer > http://niemeyer.net > http://niemeyer.net/blog > http://niemeyer.net/twitter >
