With replicated cache we can execute a query against backup partitions that were not updated yet because of PRIMARY_SYNC. Thus we do not see an update.
Sergi 2017-04-18 10:30 GMT+03:00 Dmitriy Setrakyan <dsetrak...@apache.org>: > Vladimir, > > What is wrong with a query in PRIMARY_SYNC mode? Why won't it work? > > D. > > On Tue, Apr 18, 2017 at 12:25 AM, Vladimir Ozerov <voze...@gridgain.com> > wrote: > > > Folks, > > > > I received a number of complaints from users that our default setting > favor > > performance at the cost of correctness and subtle behavior. Yesterday I > > faced one such situation on my own. > > > > I started REPLICATED cache on several nodes, put some data, executed > simple > > SQL and got wrong result. No errors, no warnings. The problem was caused > by > > default PRIMARY_SYNC mode. WTF, our cache doesn't work out of the box! > > > > Another widely known examples are data streamer behavior, "read form > > backups" + continuous queries. > > > > I propose to change our defaults to favor *correctness* over performance, > > and create good documentation and JavaDocs to explain users how to tune > our > > product. Proposed changes: > > > > 1) FULL_SYNC as default; > > 2) "readFromBackups=false" as default; > > 3) "IgniteDataStreamer.allowOverwrite=true" as default. > > > > Users should not think how to make Ignite work correctly. It should be > > correct out of the box. > > > > Vladimir. > > >
