Test for disc speeds

Framework/Utils/Formatter.cs

@@ -1,4 +1,6 @@
-namespace Utils
+using System.Globalization;
+
+namespace Utils
 {
     public static class Formatter
     {
@@ -10,7 +12,7 @@
 
             var sizeOrder = Convert.ToInt32(Math.Floor(Math.Log(bytes, 1024)));
             var digit = Math.Round(bytes / Math.Pow(1024, sizeOrder), 1);
-            return digit.ToString() + sizeSuffixes[sizeOrder];
+            return digit.ToString(CultureInfo.InvariantCulture) + sizeSuffixes[sizeOrder];
         }
     }
 }

Tests/CodexTests/ScalabilityTests/ClusterSpeedTests.cs

@@ -0,0 +1,83 @@
+using DistTestCore;
+using Logging;
+using NUnit.Framework;
+using Utils;
+
+namespace CodexTests.ScalabilityTests
+{
+    [TestFixture]
+    public class ClusterDiscSpeedTests : DistTest
+    {
+        private readonly Random random = new Random();
+
+        [Test]
+        [Combinatorial]
+        public void DiscSpeedTest(
+            [Values(1, 10, 100, 1024, 1024 * 10, 1024 * 100, 1024 * 1024)] int bufferSizeKb
+        )
+        {
+            long targetSize = (long)(1024 * 1024 * 1024) * 2;
+            long bufferSizeBytes = ((long)bufferSizeKb) * 1024;
+
+            var filename = nameof(DiscSpeedTest);
+
+            Thread.Sleep(1000);
+            if (File.Exists(filename)) File.Delete(filename);
+            Thread.Sleep(1000);
+            var writeSpeed = PerformWrite(targetSize, bufferSizeBytes, filename);
+            Thread.Sleep(1000);
+            var readSpeed = PerformRead(targetSize, bufferSizeBytes, filename);
+            
+            Log($"Write speed: {writeSpeed} per second.");
+            Log($"Read speed: {writeSpeed} per second.");
+        }
+
+        private ByteSize PerformWrite(long targetSize, long bufferSizeBytes, string filename)
+        {
+            long bytesWritten = 0;
+            var buffer = new byte[bufferSizeBytes];
+            random.NextBytes(buffer);
+
+            var sw = Stopwatch.Begin(GetTestLog());
+            using (var stream = File.OpenWrite(filename))
+            {
+                while (bytesWritten < targetSize)
+                {
+                    long remaining = targetSize - bytesWritten;
+                    long toWrite = Math.Min(bufferSizeBytes, remaining);
+
+                    stream.Write(buffer, 0, Convert.ToInt32(toWrite));
+                    bytesWritten += toWrite;
+                }
+            }
+            var duration = sw.End("WriteTime");
+            double totalSeconds = duration.TotalSeconds;
+            double totalBytes = bytesWritten;
+            double bytesPerSecond = totalBytes / totalSeconds;
+            return new ByteSize(Convert.ToInt64(bytesPerSecond));
+        }
+
+        private ByteSize PerformRead(long targetSize, long bufferSizeBytes, string filename)
+        {
+            long bytesRead = 0;
+            var buffer = new byte[bufferSizeBytes];
+            var sw = Stopwatch.Begin(GetTestLog());
+            using (var stream = File.OpenRead(filename))
+            {
+                while (bytesRead < targetSize)
+                {
+                    long remaining = targetSize - bytesRead;
+                    long toRead = Math.Min(bufferSizeBytes, remaining);
+
+                    var r = stream.Read(buffer, 0, Convert.ToInt32(toRead));
+                    bytesRead += r;
+                }
+            }
+            var duration = sw.End("ReadTime");
+            double totalSeconds = duration.TotalSeconds;
+            double totalBytes = bytesRead;
+            double bytesPerSecond = totalBytes / totalSeconds;
+            return new ByteSize(Convert.ToInt64(bytesPerSecond));
+        }
+    }
+}