bool
LoadBalancer::CheckDynamicLoadBalancing(avtContract_p input)
{
//
// See if we have already have decided. If so, just return our cached
// decision.
//
int index = input->GetPipelineIndex();
LBInfo &lbinfo = pipelineInfo[index];
if (lbinfo.haveInitializedDLB)
return lbinfo.doDLB;
//
// If the user has not explicitly asked for DLB, then don't do it.
//
if (!allowDynamic)
{
// Almost always false.
lbinfo.doDLB = false || (scheme == LOAD_BALANCE_STREAM);
lbinfo.haveInitializedDLB = true;
return lbinfo.doDLB;
}
//
// Some hard and fast rules:
//
// Pipeline index 0 is reserved for meta-data and inlined pipelines. So
// no DLB for those.
//
// Cannot dynamic load balance some pipelines because of the filters
// in the pipeline.
//
// We cannot do dynamic load balancing if the database does not believe
// we can do dynamic load balancing (for example because we need ghost
// data communicated or materials reconstructed).
//
avtDataRequest_p data = input->GetDataRequest();
std::string dbname = lbinfo.db;
avtDatabase *db = dbMap[dbname];
if (input->GetPipelineIndex() == 0 ||
input->ShouldUseStreaming() == false ||
db->CanDoStreaming(data) == false)
{
lbinfo.doDLB = false;
lbinfo.haveInitializedDLB = true;
return false;
}
//
// Don't do DLB if we have 2 or 3 procs. It's not worth it.
//
if (nProcs == 2 || nProcs == 3)
{
lbinfo.doDLB = false;
lbinfo.haveInitializedDLB = true;
return false;
}
//
// The user has asked for DLB. And nothing in the pipeline is prevent it.
// Do it!
//
lbinfo.doDLB = true;
lbinfo.haveInitializedDLB = true;
return true;
}
