Pavel, We propose changing public API so this is for Ignite 3.0.
Thanks! вт, 3 нояб. 2020 г. в 02:17, Pavel Tupitsyn <[email protected]>: > Alexey, > > Just to clarify before we start the discussion: > this proposal seems to introduce some breaking changes, so we are talking > about Ignite 3.0, correct? > > Pavel > > On Tue, Nov 3, 2020 at 12:13 AM Alexey Kukushkin < > [email protected]> > wrote: > > > Igniters, > > > > What do you think about changing .NET API to read/write portable dates by > > default and making that really portable? > > > > *The Problem* > > Presently .NET API writes dates as composite Ignite objects. Only .NET > > clients can read such dates: any other client (JDBC, Java, etc) does not > > understand it without custom deserialization. > > > > It is still possible to configure .NET serialization to write dates as > > Ignite dates - see DateTime Serialization note > > < > > > https://ignite.apache.org/docs/latest/net-specific/net-platform-interoperability#types-compatibility > > >. > > But then Ignite accepts only UTC dates, requiring the application > > developers to convert local dates to UTC dates and back. This task is not > > trivial: DateTime.ToUniversalTime > > < > > > https://docs.microsoft.com/en-us/dotnet/api/system.datetime.touniversaltime?view=netcore-3.1 > > > > > uses > > calendars different from Java (and the .NET calendars are the invalid > ones > > - especially for pre-1990 dates). > > > > The motivation for the current default behavior was probably the desire > to > > keep the Time Zone information: Ignite dates do not store time zones. > > > > In our experience interoperability is more important than storing time > zone > > info. > > > > *The Proposal* > > > > 1. Always write .NET dates as portable Ignite dates: get rid of the > > BinaryReflectiveSerializer.ForceTimestamp flag that currently triggers > > this > > behavior. > > - We could still keep the ForceTimestamp flag if saving .NET dates > as > > transparent objects seems a useful case. We do not think it is > > useful. > > 2. Automatically convert Local dates to UTC and back *inside* > > Ignite.NET. > > - In this case we lose the DateTime.Kind of UTC dates: we write a > UTC > > date but we would read a Local date since Ignite would always > > convert UTC > > to Local when reading. > > We could add a UtcDate date flag to QuerySqlFieldAttribute > > and BinaryReflectiveSerializer to control the deserialization > > behavior if > > keeping dates in UTC format use case seems important. > > 3. Use NodaTime <https://nodatime.org/> for UTC<->Local conversions. > > Noda time uses Java calendars making the conversion truely portable. > > > > *The Benefits* > > > > 1. We think portable dates are much more important than storing time > > zone info. Why do we store time zones for every date on the server > > anyway? > > Time zone is client-side info. > > 2. Simpler application code: no more manual configuration to trigger > the > > portable behavior. > > 3. Non-trivial code to make the truly portable UTC<->Local conversion > is > > implemented once inside Ignite instead of having every Ignite.NET > > application implementing it. > > > > Thank you! > > > > -- > > Best regards, > > Alexey > > > -- Best regards, Alexey
