Why does sequencer bound timestamp increment?

pdeva · May 31, 2024, 4:56pm

its this line in getVersionCxx

apple/foundationdb/blob/f1d8c5fd5ad56fbacd628bdcd3927fe88e5ed5d5/fdbserver/masterserver.actor.cpp#L177


      
          			self->version = self->recoveryTransactionVersion;
          			rep.prevVersion = self->lastEpochEnd;
          
          		} else {
          			double t1 = now();
          			if (BUGGIFY) {
          				t1 = self->lastVersionTime;
          			}
          
          			Version toAdd =
          			    std::max<Version>(1,
          			                      std::min<Version>(SERVER_KNOBS->MAX_READ_TRANSACTION_LIFE_VERSIONS,
          			                                        SERVER_KNOBS->VERSIONS_PER_SECOND * (t1 - self->lastVersionTime)));
          
          			rep.prevVersion = self->version;
          			if (self->referenceVersion.present()) {
          				self->version = figureVersion(self->version,
          				                              g_network->timer(),
          				                              self->referenceVersion.get(),
          				                              toAdd,
          				                              SERVER_KNOBS->MAX_VERSION_RATE_MODIFIER,

why is the timestamp increment bounded by MAX_READ_TRANSACTION_LIFE_VERSIONS at all? why not just have it increment by VERSIONS_PER_SECOND * (t1 - self->lastVersionTime)