private ReducingPerformanceStats SingleStepReduce(IndexToWorkOn index, List<string> keysToReduce, AbstractViewGenerator viewGenerator,
ConcurrentSet<object> itemsToDelete, CancellationToken token)
{
var needToMoveToSingleStepQueue = new ConcurrentQueue<HashSet<string>>();
if ( Log.IsDebugEnabled )
Log.Debug(() => string.Format("Executing single step reducing for {0} keys [{1}]", keysToReduce.Count, string.Join(", ", keysToReduce)));
var batchTimeWatcher = Stopwatch.StartNew();
var reducingBatchThrottlerId = Guid.NewGuid();
var reducePerformanceStats = new ReducingPerformanceStats(ReduceType.SingleStep);
var reduceLevelStats = new ReduceLevelPeformanceStats
{
Started = SystemTime.UtcNow,
Level = 2
};
try
{
var parallelOperations = new ConcurrentQueue<ParallelBatchStats>();
var parallelProcessingStart = SystemTime.UtcNow;
BackgroundTaskExecuter.Instance.ExecuteAllBuffered(context, keysToReduce, enumerator =>
{
var parallelStats = new ParallelBatchStats
{
StartDelay = (long)(SystemTime.UtcNow - parallelProcessingStart).TotalMilliseconds
};
var localNeedToMoveToSingleStep = new HashSet<string>();
needToMoveToSingleStepQueue.Enqueue(localNeedToMoveToSingleStep);
var localKeys = new HashSet<string>();
while (enumerator.MoveNext())
{
token.ThrowIfCancellationRequested();
localKeys.Add(enumerator.Current);
}
transactionalStorage.Batch(actions =>
{
var getItemsToReduceParams = new GetItemsToReduceParams(index: index.IndexId, reduceKeys: localKeys, level: 0, loadData: false, itemsToDelete: itemsToDelete)
{
Take = int.MaxValue // just get all, we do the rate limit when we load the number of keys to reduce, anyway
};
var getItemsToReduceDuration = Stopwatch.StartNew();
int scheduledItemsSum = 0;
int scheduledItemsCount = 0;
List<int> scheduledItemsMappedBuckets = new List<int>();
using (StopwatchScope.For(getItemsToReduceDuration))
{
foreach (var item in actions.MapReduce.GetItemsToReduce(getItemsToReduceParams, token))
{
scheduledItemsMappedBuckets.Add(item.Bucket);
scheduledItemsSum += item.Size;
scheduledItemsCount++;
}
}
parallelStats.Operations.Add(PerformanceStats.From(IndexingOperation.Reduce_GetItemsToReduce, getItemsToReduceDuration.ElapsedMilliseconds));
autoTuner.CurrentlyUsedBatchSizesInBytes.GetOrAdd(reducingBatchThrottlerId, scheduledItemsSum);
if (scheduledItemsCount == 0)
{
// Here we have an interesting issue. We have scheduled reductions, because GetReduceTypesPerKeys() returned them
// and at the same time, we don't have any at level 0. That probably means that we have them at level 1 or 2.
// They shouldn't be here, and indeed, we remove them just a little down from here in this function.
// That said, they might have smuggled in between versions, or something happened to cause them to be here.
// In order to avoid that, we forcibly delete those extra items from the scheduled reductions, and move on
Log.Warn("Found single reduce items ({0}) that didn't have any items to reduce. Deleting level 1 & level 2 items for those keys. (If you can reproduce this, please contact [email protected])", string.Join(", ", keysToReduce));
var deletingScheduledReductionsDuration = Stopwatch.StartNew();
using (StopwatchScope.For(deletingScheduledReductionsDuration))
{
foreach (var reduceKey in keysToReduce)
{
token.ThrowIfCancellationRequested();
actions.MapReduce.DeleteScheduledReduction(index.IndexId, 1, reduceKey);
actions.MapReduce.DeleteScheduledReduction(index.IndexId, 2, reduceKey);
}
}
parallelStats.Operations.Add(PerformanceStats.From(IndexingOperation.Reduce_DeleteScheduledReductions, deletingScheduledReductionsDuration.ElapsedMilliseconds));
}
var removeReduceResultsDuration = new Stopwatch();
foreach (var reduceKey in localKeys)
{
token.ThrowIfCancellationRequested();
var lastPerformedReduceType = actions.MapReduce.GetLastPerformedReduceType(index.IndexId, reduceKey);
if (lastPerformedReduceType != ReduceType.SingleStep)
localNeedToMoveToSingleStep.Add(reduceKey);
if (lastPerformedReduceType != ReduceType.MultiStep)
continue;
if ( Log.IsDebugEnabled )
{
Log.Debug("Key {0} was moved from multi step to single step reduce, removing existing reduce results records", reduceKey);
}
using (StopwatchScope.For(removeReduceResultsDuration))
{
// now we are in single step but previously multi step reduce was performed for the given key
var mappedBuckets = actions.MapReduce.GetMappedBuckets(index.IndexId, reduceKey, token);
// add scheduled items too to be sure we will delete reduce results of already deleted documents
foreach (var mappedBucket in mappedBuckets.Union(scheduledItemsMappedBuckets))
{
actions.MapReduce.RemoveReduceResults(index.IndexId, 1, reduceKey, mappedBucket);
actions.MapReduce.RemoveReduceResults(index.IndexId, 2, reduceKey, mappedBucket / 1024);
}
}
}
parallelStats.Operations.Add(PerformanceStats.From(IndexingOperation.Reduce_RemoveReduceResults, removeReduceResultsDuration.ElapsedMilliseconds));
parallelOperations.Enqueue(parallelStats);
});
});
reduceLevelStats.Operations.Add(new ParallelPerformanceStats
{
NumberOfThreads = parallelOperations.Count,
DurationMs = (long)(SystemTime.UtcNow - parallelProcessingStart).TotalMilliseconds,
BatchedOperations = parallelOperations.ToList()
});
var getMappedResultsDuration = new Stopwatch();
var reductionPerformanceStats = new List<IndexingPerformanceStats>();
var keysLeftToReduce = new HashSet<string>(keysToReduce);
while (keysLeftToReduce.Count > 0)
{
var keysReturned = new HashSet<string>();
// Try to diminish the allocations happening because of .Resize()
var mappedResults = new List<MappedResultInfo>(keysLeftToReduce.Count);
context.TransactionalStorage.Batch(actions =>
{
var take = context.CurrentNumberOfItemsToReduceInSingleBatch;
using (StopwatchScope.For(getMappedResultsDuration))
{
mappedResults = actions.MapReduce.GetMappedResults(index.IndexId, keysLeftToReduce, true, take, keysReturned, token, mappedResults);
}
});
var count = mappedResults.Count;
int size = 0;
foreach ( var item in mappedResults )
{
item.Bucket = 0;
size += item.Size;
}
var results = mappedResults.GroupBy(x => x.Bucket, x => JsonToExpando.Convert(x.Data)).ToArray();
context.MetricsCounters.ReducedPerSecond.Mark(results.Length);
token.ThrowIfCancellationRequested();
var performance = context.IndexStorage.Reduce(index.IndexId, viewGenerator, results, 2, context, null, keysReturned, count);
reductionPerformanceStats.Add(performance);
autoTuner.AutoThrottleBatchSize(count, size, batchTimeWatcher.Elapsed);
}
var needToMoveToSingleStep = new HashSet<string>();
HashSet<string> set;
while (needToMoveToSingleStepQueue.TryDequeue(out set))
{
needToMoveToSingleStep.UnionWith(set);
}
foreach (var reduceKey in needToMoveToSingleStep)
{
string localReduceKey = reduceKey;
transactionalStorage.Batch(actions =>
actions.MapReduce.UpdatePerformedReduceType(index.IndexId, localReduceKey, ReduceType.SingleStep));
}
reduceLevelStats.Completed = SystemTime.UtcNow;
reduceLevelStats.Duration = reduceLevelStats.Completed - reduceLevelStats.Started;
reduceLevelStats.Operations.Add(PerformanceStats.From(IndexingOperation.Reduce_GetMappedResults, getMappedResultsDuration.ElapsedMilliseconds));
reduceLevelStats.Operations.Add(PerformanceStats.From(IndexingOperation.StorageCommit, 0)); // in single step we write directly to Lucene index
foreach (var stats in reductionPerformanceStats)
{
reduceLevelStats.Add(stats);
}
reducePerformanceStats.LevelStats.Add(reduceLevelStats);
}
finally
{
long _;
autoTuner.CurrentlyUsedBatchSizesInBytes.TryRemove(reducingBatchThrottlerId, out _);
}
return reducePerformanceStats;
}
private ReducingPerformanceStats MultiStepReduce(IndexToWorkOn index, List<string> keysToReduce, AbstractViewGenerator viewGenerator, ConcurrentSet<object> itemsToDelete, CancellationToken token)
{
var needToMoveToMultiStep = new HashSet<string>();
transactionalStorage.Batch(actions =>
{
foreach (var localReduceKey in keysToReduce)
{
token.ThrowIfCancellationRequested();
var lastPerformedReduceType = actions.MapReduce.GetLastPerformedReduceType(index.IndexId, localReduceKey);
if (lastPerformedReduceType != ReduceType.MultiStep)
needToMoveToMultiStep.Add(localReduceKey);
if (lastPerformedReduceType != ReduceType.SingleStep)
continue;
// we exceeded the limit of items to reduce in single step
// now we need to schedule reductions at level 0 for all map results with given reduce key
var mappedItems = actions.MapReduce.GetMappedBuckets(index.IndexId, localReduceKey, token).ToList();
foreach (var result in mappedItems.Select(x => new ReduceKeyAndBucket(x, localReduceKey)))
{
actions.MapReduce.ScheduleReductions(index.IndexId, 0, result);
}
}
});
var reducePerformance = new ReducingPerformanceStats(ReduceType.MultiStep);
var keysToReduceSet = new HashSet<string>(keysToReduce);
for (int i = 0; i < 3; i++)
{
var level = i;
var reduceLevelStats = new ReduceLevelPeformanceStats()
{
Level = level,
Started = SystemTime.UtcNow,
};
var reduceParams = new GetItemsToReduceParams(
index.IndexId,
keysToReduceSet,
level,
true,
itemsToDelete);
var gettingItemsToReduceDuration = new Stopwatch();
var scheduleReductionsDuration = new Stopwatch();
var removeReduceResultsDuration = new Stopwatch();
var storageCommitDuration = new Stopwatch();
bool retry = true;
while (retry && reduceParams.ReduceKeys.Count > 0)
{
var reduceBatchAutoThrottlerId = Guid.NewGuid();
try
{
transactionalStorage.Batch(actions =>
{
token.ThrowIfCancellationRequested();
actions.BeforeStorageCommit += storageCommitDuration.Start;
actions.AfterStorageCommit += storageCommitDuration.Stop;
var batchTimeWatcher = Stopwatch.StartNew();
reduceParams.Take = context.CurrentNumberOfItemsToReduceInSingleBatch;
int size = 0;
IList<MappedResultInfo> persistedResults;
var reduceKeys = new HashSet<string>(StringComparer.InvariantCultureIgnoreCase);
using (StopwatchScope.For(gettingItemsToReduceDuration))
{
persistedResults = actions.MapReduce.GetItemsToReduce(reduceParams, token);
foreach (var item in persistedResults)
{
reduceKeys.Add(item.ReduceKey);
size += item.Size;
}
}
if (persistedResults.Count == 0)
{
retry = false;
return;
}
var count = persistedResults.Count;
autoTuner.CurrentlyUsedBatchSizesInBytes.GetOrAdd(reduceBatchAutoThrottlerId, size);
if (Log.IsDebugEnabled)
{
if (persistedResults.Count > 0)
{
Log.Debug(() => string.Format("Found {0} results for keys [{1}] for index {2} at level {3} in {4}",
persistedResults.Count,
string.Join(", ", persistedResults.Select(x => x.ReduceKey).Distinct()),
index.IndexId, level, batchTimeWatcher.Elapsed));
}
else
{
Log.Debug("No reduce keys found for {0}", index.IndexId);
}
}
token.ThrowIfCancellationRequested();
var requiredReduceNextTimeSet = new HashSet<ReduceKeyAndBucket>(persistedResults.Select(x => new ReduceKeyAndBucket(x.Bucket, x.ReduceKey)), ReduceKeyAndBucketEqualityComparer.Instance);
using (StopwatchScope.For(removeReduceResultsDuration))
{
foreach (var mappedResultInfo in requiredReduceNextTimeSet)
{
token.ThrowIfCancellationRequested();
actions.MapReduce.RemoveReduceResults(index.IndexId, level + 1, mappedResultInfo.ReduceKey, mappedResultInfo.Bucket);
}
}
if (level != 2)
{
var reduceKeysAndBucketsSet = new HashSet<ReduceKeyAndBucket>(requiredReduceNextTimeSet.Select(x => new ReduceKeyAndBucket(x.Bucket / 1024, x.ReduceKey)), ReduceKeyAndBucketEqualityComparer.Instance);
using (StopwatchScope.For(scheduleReductionsDuration))
{
foreach (var reduceKeysAndBucket in reduceKeysAndBucketsSet)
{
token.ThrowIfCancellationRequested();
actions.MapReduce.ScheduleReductions(index.IndexId, level + 1, reduceKeysAndBucket);
}
}
}
token.ThrowIfCancellationRequested();
var reduceTimeWatcher = Stopwatch.StartNew();
var results = persistedResults.Where(x => x.Data != null)
.GroupBy(x => x.Bucket, x => JsonToExpando.Convert(x.Data));
var performance = context.IndexStorage.Reduce(index.IndexId, viewGenerator, results, level, context, actions, reduceKeys, persistedResults.Count);
context.MetricsCounters.ReducedPerSecond.Mark(results.Count());
reduceLevelStats.Add(performance);
var batchDuration = batchTimeWatcher.Elapsed;
if ( Log.IsDebugEnabled )
{
Log.Debug("Indexed {0} reduce keys in {1} with {2} results for index {3} in {4} on level {5}", reduceKeys.Count, batchDuration, performance.ItemsCount, index.IndexId, reduceTimeWatcher.Elapsed, level);
}
autoTuner.AutoThrottleBatchSize(count, size, batchDuration);
});
}
finally
{
long _;
autoTuner.CurrentlyUsedBatchSizesInBytes.TryRemove(reduceBatchAutoThrottlerId, out _);
}
}
reduceLevelStats.Completed = SystemTime.UtcNow;
reduceLevelStats.Duration = reduceLevelStats.Completed - reduceLevelStats.Started;
reduceLevelStats.Operations.Add(PerformanceStats.From(IndexingOperation.Reduce_GetItemsToReduce, gettingItemsToReduceDuration.ElapsedMilliseconds));
reduceLevelStats.Operations.Add(PerformanceStats.From(IndexingOperation.Reduce_ScheduleReductions, scheduleReductionsDuration.ElapsedMilliseconds));
reduceLevelStats.Operations.Add(PerformanceStats.From(IndexingOperation.Reduce_RemoveReduceResults, removeReduceResultsDuration.ElapsedMilliseconds));
reduceLevelStats.Operations.Add(PerformanceStats.From(IndexingOperation.StorageCommit, storageCommitDuration.ElapsedMilliseconds));
reducePerformance.LevelStats.Add(reduceLevelStats);
}
foreach (var reduceKey in needToMoveToMultiStep)
{
token.ThrowIfCancellationRequested();
string localReduceKey = reduceKey;
transactionalStorage.Batch(actions =>
actions.MapReduce.UpdatePerformedReduceType(index.IndexId, localReduceKey,
ReduceType.MultiStep));
}
return reducePerformance;
}