On 31 January 2013 21:36, Thomas Mueller <[email protected]> wrote: > Hi, > >>fuzzy distributed >>time signal (as used in Google Spanner) > > > That's quite interesting actually: Google Spanner relies on cluster nodes > having very accurate clocks (atomic clocks / GPS): "TrueTime"
Only for the masters and then only to tie geographically distributed servers to the same concept of TrueTime. In the same datacenter I think the algorithm relies on determining jitter between nodes and masters can agree amongst themselves what TrueTime is. However for those that can't put GPS clocks into distributed datacenters, and have control over the quality of the low level hardware the fuzz on TrueTime is going to be too large to be of use. I was thinking a highly accurate timestamp with knowledge of the jitter might help in conflict resolution at merge time.... but maybe not. Ian > > http://www.wired.com/wiredenterprise/2012/09/google-spanner/all/ > http://static.googleusercontent.com/external_content/untrusted_dlcp/researc > h.google.com/en//archive/spanner-osdi2012.pdf > > > Regards, > Thomas >
