Hi Juan, Thanks for your answer.
According to https://cwiki.apache.org/confluence/display/GEODE/Managing+Backward+Compatibility there are two ways to manage backward compatibility for classes that implement SerializationVersions. Either implementing `toDataPre/fromDataPre` methods that Data Serialization will invoke based on the version of the sender/receiver (preferred way), or using `fromData/toData` methods using `InternalDataSerializer.getVersionForDataStream`. In the case of this class, we have `toDataPre/fromDataPre` methods implemented so, according to what is described in the wiki, it should not be necessary to add any extra check to the `fromData/toData`methods. But there is this check I mentioned which is necessary according to some backward compatibility tests in Geode. So my question is why is it necessary? Thanks, -Alberto ________________________________ From: Ju@N <jujora...@gmail.com> Sent: Tuesday, May 19, 2020 2:54 PM To: dev@geode.apache.org <dev@geode.apache.org> Subject: Re: Question about version checks inside fromData method in GatewaySenderEventImpl Hello Alberto, It looks like the property *isConcurrencyConflict* was added as part of *GEODE-3967* [1] and this was released as part of Geode 1.9.0; that seems to the reason why the check is in place: if we get an instance of *GatewaySenderEventImpl* from a member running a version higher than 1.9.0 then we are 100% sure that the serialized form will contain the new field so we can parse it, if the serialized *GatewaySenderEventImpl *comes from an older member the filed won't be there so we don't even try to parse it. Hope I didn't miss anything. Cheers. [1]: https://issues.apache.org/jira/browse/GEODE-3967 On Tue, 19 May 2020 at 13:14, Alberto Gomez <alberto.go...@est.tech> wrote: > Hi, > > Looking at the fromData method of GatewaySenderEventImpl I see that it > contains a conditional reading of the isConcurrencyConflict when version is > greater than Geode 1.9.0 one. See below: > > @Override > public void fromData(DataInput in, > DeserializationContext context) throws IOException, > ClassNotFoundException { > fromDataPre_GEODE_1_9_0_0(in, context); > if (version >= Version.GEODE_1_9_0.ordinal()) { > this.isConcurrencyConflict = DataSerializer.readBoolean(in); > } > } > > I have looked at the implementation of this method in other classes and > have not seen this checking of version pattern. I have also observed that > if the "if" is removed some backward compatibility tests fail. > > Could anybody tell me why this check (the if) is necessary given that > there is already a fromDataPre_GEODE_1_9_0 method in the class? > > Thanks in advance, > > -Alberto G. > -- Ju@N
