private void FillInfo(DiskUsageInfo toFill, DiskStats previousDiskStats, DiskStats diskStats, double deltaSeconds)
{
var readsDelta = diskStats.ReadsCount - previousDiskStats.ReadsCount;
var writesDelta = diskStats.WritesCount - previousDiskStats.WritesCount;
var sectorsReadDelta = diskStats.SectorsReadCount - previousDiskStats.SectorsReadCount;
var sectorsWrittenDelta = diskStats.SectorsWrittenCount - previousDiskStats.SectorsWrittenCount;
var msReadDelta = diskStats.MsSpentReading - previousDiskStats.MsSpentReading;
var msWriteDelta = diskStats.MsSpentWriting - previousDiskStats.MsSpentWriting;
var msSpentDoingIoDelta = diskStats.MsSpentDoingIo - previousDiskStats.MsSpentDoingIo;
if (readsDelta > 0)
{
toFill.ReadAverageMsLatency = (long)((double)msReadDelta / readsDelta);
}
if (writesDelta > 0)
{
toFill.WriteAverageMsLatency = (long)((double)msWriteDelta / writesDelta);
}
toFill.CurrentQueueLength = diskStats.CurrentQueueLength;
if (deltaSeconds > 0d)
{
toFill.ReadsPerSecond = (long)(readsDelta / deltaSeconds);
toFill.WritesPerSecond = (long)(writesDelta / deltaSeconds);
// NOTE: Every sector equals 512B, so it's easy to convert these values.
// NOTE: See https://www.man7.org/linux/man-pages/man1/iostat.1.html for details about sector size.
toFill.BytesReadPerSecond = (long)(sectorsReadDelta * 512d / deltaSeconds);
toFill.BytesWrittenPerSecond = (long)(sectorsWrittenDelta * 512d / deltaSeconds);
toFill.UtilizedPercent = (100d * msSpentDoingIoDelta / (deltaSeconds * 1000)).Clamp(0, 100);
}
}
public void Collect(HostMetrics metrics)
{
var deltaSeconds = stopwatch.Elapsed.TotalSeconds;
var newDisksStatsInfo = new Dictionary <string, DiskStats>();
var disksUsageInfo = new Dictionary <string, DiskUsageInfo>();
foreach (var diskStats in ParseDiskstats(diskStatsReader.ReadLines()))
{
var result = new DiskUsageInfo {
DiskName = diskStats.DiskName
};
if (previousDisksStatsInfo.TryGetValue(diskStats.DiskName, out var previousDiskStats))
{
FillInfo(result, previousDiskStats, diskStats, deltaSeconds);
}
disksUsageInfo[result.DiskName] = result;
newDisksStatsInfo[diskStats.DiskName] = diskStats;
}
metrics.DisksUsageInfo = disksUsageInfo;
previousDisksStatsInfo = newDisksStatsInfo;
stopwatch.Restart();
}
