public void SiloStatisticsChangeNotification(SiloAddress updatedSilo, SiloRuntimeStatistics newSiloStats)
{
// just create a new empty CachedLocalStat and throw the old one.
var updatedCacheEntry = new CachedLocalStat(updatedSilo, newSiloStats);
localCache.AddOrUpdate(updatedSilo, k => updatedCacheEntry, (k, v) => updatedCacheEntry);
}
/// <summary>
/// Selects the best match from list of silos, updates local statistics.
/// </summary>
/// <note>
/// This is equivalent with SelectSiloPowerOfK() with chooseHowMany = #Silos
/// </note>
private Task <PlacementResult> SelectSiloGreedy(PlacementStrategy strategy, GrainId grain, IPlacementContext context)
{
int minLoad = int.MaxValue;
CachedLocalStat minLoadedSilo = null;
foreach (CachedLocalStat current in localCache.Values)
{
if (IsSiloOverloaded(current.SiloStats))
{
continue;
}
int load = SiloLoad_ByRecentActivations(current);
if (load >= minLoad)
{
continue;
}
minLoadedSilo = current;
minLoad = load;
}
if (minLoadedSilo != null)
{
return(MakePlacement(strategy, grain, context, minLoadedSilo));
}
var debugLog = string.Format("Unable to select a candidate from {0} silos: {1}", localCache.Count,
Utils.EnumerableToString(
localCache,
kvp => String.Format("SiloAddress = {0} -> {1}", kvp.Key.ToString(), kvp.Value.ToString())));
logger.Warn(ErrorCode.Placement_ActivationCountBasedDirector_NoSilos, debugLog);
throw new OrleansException(debugLog);
}
private Task <SiloAddress> MakePlacement(CachedLocalStat minLoadedSilo)
{
// Increment placement by number of silos instead of by one.
// This is our trick to get more balanced placement, accounting to the probable
// case when multiple silos place on the same silo at the same time, before stats are refreshed.
minLoadedSilo.IncrementActivationCount(localCache.Count);
return(Task.FromResult(minLoadedSilo.Address));
}
private Task<PlacementResult> MakePlacement(PlacementStrategy strategy, GrainId grain, IPlacementContext context, CachedLocalStat minLoadedSilo)
{
// Increment placement by number of silos instead of by one.
// This is our trick to get more balanced placement, accounting to the probable
// case when multiple silos place on the same silo at the same time, before stats are refreshed.
minLoadedSilo.IncrementActivationCount(localCache.Count);
return Task.FromResult(PlacementResult.SpecifyCreation(
minLoadedSilo.Address,
strategy,
context.GetGrainTypeName(grain)));
}
public Task <SiloAddress> SelectSiloPowerOfK(PlacementStrategy strategy, PlacementTarget target, IPlacementContext context)
{
var compatibleSilos = context.GetCompatibleSilos(target);
// Exclude overloaded and non-compatible silos
var relevantSilos = new List <CachedLocalStat>();
foreach (CachedLocalStat current in localCache.Values)
{
if (IsSiloOverloaded(current.SiloStats))
{
continue;
}
if (!compatibleSilos.Contains(current.Address))
{
continue;
}
relevantSilos.Add(current);
}
if (relevantSilos.Count > 0)
{
int chooseFrom = Math.Min(relevantSilos.Count, chooseHowMany);
var chooseFromThoseSilos = new List <CachedLocalStat>();
while (chooseFromThoseSilos.Count < chooseFrom)
{
int index = ThreadSafeRandom.Next(relevantSilos.Count);
var pickedSilo = relevantSilos[index];
relevantSilos.RemoveAt(index);
chooseFromThoseSilos.Add(pickedSilo);
}
CachedLocalStat minLoadedSilo = chooseFromThoseSilos.First();
foreach (CachedLocalStat s in chooseFromThoseSilos)
{
if (SiloLoad_ByRecentActivations(s) < SiloLoad_ByRecentActivations(minLoadedSilo))
{
minLoadedSilo = s;
}
}
return(MakePlacement(minLoadedSilo));
}
var debugLog = string.Format("Unable to select a candidate from {0} silos: {1}", localCache.Count,
Utils.EnumerableToString(
localCache,
kvp => String.Format("SiloAddress = {0} -> {1}", kvp.Key.ToString(), kvp.Value.ToString())));
logger.Warn(ErrorCode.Placement_ActivationCountBasedDirector_NoSilos, debugLog);
throw new OrleansException(debugLog);
}
private int SiloLoad_ByActivations(CachedLocalStat cachedStats)
{
return(useLocalCache ?
cachedStats.ActivationCount + cachedStats.SiloStats.ActivationCount :
cachedStats.SiloStats.ActivationCount);
}
private Task <PlacementResult> MakePlacement(PlacementStrategy strategy, GrainId grain, IPlacementContext context, CachedLocalStat minLoadedSilo)
{
// Increment placement by number of silos instead of by one.
// This is our trick to get more balanced placement, accounting to the probable
// case when multiple silos place on the same silo at the same time, before stats are refreshed.
minLoadedSilo.IncrementActivationCount(localCache.Count);
return(Task.FromResult(PlacementResult.SpecifyCreation(
minLoadedSilo.Address,
strategy,
context.GetGrainTypeName(grain))));
}
private int SiloLoad_ByRecentActivations(CachedLocalStat cachedStats)
{
return useLocalCache ?
cachedStats.ActivationCount + cachedStats.SiloStats.RecentlyUsedActivationCount :
cachedStats.SiloStats.RecentlyUsedActivationCount;
}
public void SiloStatisticsChangeNotification(SiloAddress updatedSilo, SiloRuntimeStatistics newSiloStats)
{
// just create a new empty CachedLocalStat and throw the old one.
var updatedCacheEntry = new CachedLocalStat(updatedSilo, newSiloStats);
localCache.AddOrUpdate(updatedSilo, k => updatedCacheEntry, (k, v) => updatedCacheEntry);
}
