On Mon, Sep 18, 2017 at 2:39 AM, Semyon Boikov <sboi...@apache.org> wrote:
> > 1. MVCC will definitely bring some performance overhead, so I think it > should not be enabled by default, I'm going to add special flag on cache > configuration: CacheConfiguration.isMvccEnabled. > Is it possible for several caches in the same cache group to have different MVCC configuration? > 2. In current mvcc architecture there should be some node in cluster > assigning versions for tx updates and queries (mvcc coordinator). Mvcc > coordinator is crucial component and it should perform as fast as possible. > It seems we need introduce special 'dedicated mvcc coordinator' node role: > it should not be possible to start cache on such node and it should not > process user's compute jobs. At the same time it should be possible that > any regular server node can become mvcc coordinator: this can be useful > during development (no extra setup for mvcc will be needed), or support > scenario when all dedicated coordinator nodes fail. So we need a way to > make node a 'dedicated mvcc coordinator', we can add special flag on ignite > configuration: IgniteConfiguration.isMvccCoordinator. > I agree that we need coordinator nodes, but I do not understand why can't we reuse some cache nodes for it? Why do we need to ask user to start up yet another type of node?
