Re: question about transaction operation in ForCES protocol draft!

[Chuanhuang Li <[e-mail]>]

B and C must roll back In this case,and CE must send a CMMIT message again(TP flag is ABT(abort)).They may release resources when they have rolled back!


Date: Tue, 25 Dec 2007 09:23:35 +0800From: [e-mail]: Re: question about transaction operation in ForCES protocol draft!To: [e-mail]


Have composed a reply yestoday but can't make it sent to the maillist.I also think TRCOMP is necessary in transaction failure handling.Think of a multiple FE transaction joined by A B C,supposed A fail to commit the transaciton and B C success,then if CE don't send TRCOMP,A could release resources,but how could B and C do?Yours,Fenggen > Date: Mon, 24 Dec 2007 10:07:16 -0500> From: [e-mail]> Subject: Re: question about transaction operation in ForCES protocol draft!> To: [e-mail]> > Dear Chuanhuang Li,> > I think i understand you now - i apologize it took me 3 emails;-> > > You have been saying: TRCOMP matters only for the success case but not> for the failure case.> You are right in the case where we assume that the CE will be failing> the transaction immediately as the text currently reads - which is more> reasonable in the case of a single FE; however, it is feasible that a> failure may trigger the CE to do something else to make some resource> avai
 lable.> > In any case, i dont think the extra TRCOMP message is incorrect in the> case of failure. I also dont think we really should be making an update> to the protocol at this stage of the game for something that is an> optimization - I will let Avri who is the editor and shepherd of the> draft to make that decision.> > cheers,> jamal> > On Mon, 2007-24-12 at 19:26 +0800, Chuanhuang Li wrote:> > Dear jamal:> > Thanks very much!> > The following is my viewpoints:> > 1:As you said,yes,a single FE on the NE is just one case.But what I> > said is also fit for multiple FEs.> > > > 2:Only the FEs which executed the transaction messages successfully> > wait for the TRCOMP.The FEs which failed will clear the state they> > have kept immediately ,because the information which they have saved> > for possible rollback is useless,and thay needn't wait for the TRCOMP.> > > > 3:The CE needn't tell the FE "please purge state on failure without> > waiting for TRCOMP".> > For multiple FEs:
 > > The whole transaction failed,if CE recevied one COMMIT-RESPONSE> > message which indicated the execution failed from any FE.in this> > case,CE only need send COMMIT message(abort) to the FEs which executed> > successfully,it needn't send the TRCOMP!> > The whole transaction succeed,if CE recevied COMMIT-RESPONSE> > message which indicated the exec! ution succeed from all FEs!in this> > case ,CE need send TRCOMP to all FEs.> > For sigle FE:> > It is the same with multiple FEs.If CE received COMMIT-RESPONSE> > message which indicated the execution failed,it needn't send the> > TRCOMP!> >

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