public RobustHistogram MergeResults(int samples)
{
var merged = new RobustHistogram(this.Scale);
foreach (var histo in this.Histos.Reverse <RobustHistogram>().Take(samples))
{
merged.Merge(histo);
}
return(merged);
}
public void Merge(RobustHistogram other)
{
if (other.Min < this.Min)
{
this.Min = other.Min;
}
if (other.Max > this.Max)
{
this.Max = other.Max;
}
this.Count += other.Count;
this.InternalSum += other.InternalSum;
this.InternalSumSquares += other.InternalSumSquares;
for (int b = 0; b < NumBuckets; b++)
{
this.Buckets[b] += other.Buckets[b];
}
}
private RobustHistogram GetFrame(TimeSpan elapsed)
{
int index = GetGraphIndex(elapsed);
if (index != this.LastIndex && this.Completed != null && HasFrame(this.LastIndex))
{
if (this.Completed(this.Histos[this.LastIndex - this.Offset], this.LastIndex))
{ // reset!
this.Histos.Clear();
this.Offset = this.LastIndex;
}
this.LastIndex = index;
}
while (!HasFrame(index))
{
var histo = new RobustHistogram(this.Scale);
this.Histos.Add(histo);
}
return(this.Histos[index - this.Offset]);
}
public RobustHistogram MergeResults(int samples)
{
var merged = new RobustHistogram(this.Scale);
foreach (var histo in this.Histos.Reverse<RobustHistogram>().Take(samples))
{
merged.Merge(histo);
}
return merged;
}
private RobustHistogram GetFrame(TimeSpan elapsed)
{
int index = GetGraphIndex(elapsed);
if (index != this.LastIndex && this.Completed != null && HasFrame(this.LastIndex))
{
if (this.Completed(this.Histos[this.LastIndex - this.Offset], this.LastIndex))
{ // reset!
this.Histos.Clear();
this.Offset = this.LastIndex;
}
this.LastIndex = index;
}
while (!HasFrame(index))
{
var histo = new RobustHistogram(this.Scale);
this.Histos.Add(histo);
}
return this.Histos[index - this.Offset];
}
public RobustTimeLine(TimeSpan step, RobustHistogram.TimeScale scale = RobustHistogram.TimeScale.Milliseconds, Func<RobustHistogram, int, bool> onCompleted = null)
{
if (step <= TimeSpan.Zero) throw new ArgumentException("Time step must be greater than zero", "step");
this.Histos = new List<RobustHistogram>();
this.Step = step;
this.Completed = onCompleted;
this.Clock = Stopwatch.StartNew();
}
public void Merge(RobustHistogram other)
{
if (other.Min < this.Min) this.Min = other.Min;
if (other.Max > this.Max) this.Max = other.Max;
this.Count += other.Count;
this.InternalSum += other.InternalSum;
this.InternalSumSquares += other.InternalSumSquares;
for (int b = 0; b < NumBuckets; b++)
{
this.Buckets[b] += other.Buckets[b];
}
}
public async Task Run(IFdbDatabase db, TextWriter log, CancellationToken ct)
{
// estimate the number of machines...
Console.WriteLine("# Detecting cluster topology...");
var servers = await db.QueryAsync(tr => tr
.WithReadAccessToSystemKeys()
.GetRange(FdbKeyRange.StartsWith(Fdb.System.ServerList))
.Select(kvp => new
{
Node = kvp.Value.Substring(8, 16).ToHexaString(),
Machine = kvp.Value.Substring(24, 16).ToHexaString(),
DataCenter = kvp.Value.Substring(40, 16).ToHexaString()
}),
ct
);
var numNodes = servers.Select(s => s.Node).Distinct().Count();
var numMachines = servers.Select(s => s.Machine).Distinct().Count();
var numDCs = servers.Select(s => s.DataCenter).Distinct().Count();
Console.WriteLine("# > Found " + numNodes + " process(es) on " + numMachines + " machine(s) in " + numDCs + " datacenter(s)");
Console.WriteLine("# Reading list of shards...");
// dump keyServers
var ranges = await Fdb.System.GetChunksAsync(db, FdbKey.MinValue, FdbKey.MaxValue, ct);
Console.WriteLine("# > Found " + ranges.Count + " shards:");
// take a sample
var rnd = new Random(1234);
int sz = Math.Max((int)Math.Ceiling(this.Ratio * ranges.Count), 1);
if (sz > 500) sz = 500; //SAFETY
if (sz < 50) sz = Math.Max(sz, Math.Min(50, ranges.Count));
var samples = new List<FdbKeyRange>();
for (int i = 0; i < sz; i++)
{
int p = rnd.Next(ranges.Count);
samples.Add(ranges[p]);
ranges.RemoveAt(p);
}
Console.WriteLine("# Sampling " + sz + " out of " + ranges.Count + " shards (" + (100.0 * sz / ranges.Count).ToString("N1") + "%) ...");
Console.WriteLine("{0,9}{1,10}{2,10}{3,10} : K+V size distribution", "Count", "Keys", "Values", "Total");
var rangeOptions = new FdbRangeOptions { Mode = FdbStreamingMode.WantAll };
samples = samples.OrderBy(x => x.Begin).ToList();
long total = 0;
int workers = Math.Min(numMachines, 8);
var sw = Stopwatch.StartNew();
var tasks = new List<Task>();
while(samples.Count > 0)
{
while (tasks.Count < workers && samples.Count > 0)
{
var range = samples[0];
samples.RemoveAt(0);
tasks.Add(Task.Run(async () =>
{
var hh = new RobustHistogram(RobustHistogram.TimeScale.Ticks);
#region Method 1: get_range everything...
using (var tr = db.BeginTransaction(ct))
{
long keySize = 0;
long valueSize = 0;
long count = 0;
int iter = 0;
var beginSelector = FdbKeySelector.FirstGreaterOrEqual(range.Begin);
var endSelector = FdbKeySelector.FirstGreaterOrEqual(range.End);
while (true)
{
FdbRangeChunk data = default(FdbRangeChunk);
FdbException error = null;
try
{
data = await tr.Snapshot.GetRangeAsync(
beginSelector,
endSelector,
rangeOptions,
iter
).ConfigureAwait(false);
}
catch (FdbException e)
{
error = e;
}
if (error != null)
{
await tr.OnErrorAsync(error.Code).ConfigureAwait(false);
continue;
}
if (data.Count == 0) break;
count += data.Count;
foreach (var kvp in data.Chunk)
{
keySize += kvp.Key.Count;
valueSize += kvp.Value.Count;
hh.Add(TimeSpan.FromTicks(kvp.Key.Count + kvp.Value.Count));
}
if (!data.HasMore) break;
beginSelector = FdbKeySelector.FirstGreaterThan(data.Last.Key);
++iter;
}
long totalSize = keySize + valueSize;
Interlocked.Add(ref total, totalSize);
Console.WriteLine("{0,9}{1,10}{2,10}{3,10} : {4}", count.ToString("N0"), FormatSize(keySize), FormatSize(valueSize), FormatSize(totalSize), hh.GetDistribution(begin: 1, end: 10000, fold:2));
}
#endregion
#region Method 2: estimate the count using key selectors...
//long counter = await Fdb.System.EstimateCountAsync(db, range, ct);
//Console.WriteLine("COUNT = " + counter.ToString("N0"));
#endregion
}, ct));
}
var done = await Task.WhenAny(tasks);
tasks.Remove(done);
}
await Task.WhenAll(tasks);
sw.Stop();
Console.WriteLine("> Sampled " + FormatSize(total) + " (" + total.ToString("N0") + " bytes) in " + sw.Elapsed.TotalSeconds.ToString("N1") + " sec");
Console.WriteLine("> Estimated total size is " + FormatSize(total * ranges.Count / sz));
}
