[NEW PATCH] Related BZ#720385 - Report disk latency (read , write & flush ) for each storage device. (via gerrit-bot)

[Igor Lvovsky]

New patch submitted by Igor Lvovsky (ilvovsky(a)redhat.com)

You can review this change at: http://gerrit.usersys.redhat.com/935

commit 21cfe4c8c08191908142fcfa98346f811fd90739
Author: Igor Lvovsky <ilvovsky(a)redhat.com&gt;
Date:   Wed Sep 14 16:37:36 2011 +0300

    Related BZ#720385 - Report disk latency (read , write & flush ) for each storage
device.
    
    This patch temporary return zeros instead of real latency values.
    The real values will be returned when libvirt will support python binding for
virDomainQemuMonitor command.
    
    Change-Id: Id0d3d4869bcf35ed4d2ff72a5e1ef7aa21fe3455

diff --git a/vdsm/config.py b/vdsm/config.py
index 217b58c..7ad29d9 100644
--- a/vdsm/config.py
+++ b/vdsm/config.py
@@ -80,6 +80,8 @@ config.set('vars', 'vm_sample_cpu_interval',
'15')
 config.set('vars', 'vm_sample_cpu_window', '2')
 config.set('vars', 'vm_sample_disk_interval', '60')
 config.set('vars', 'vm_sample_disk_window', '2')
+config.set('vars', 'vm_sample_disk_latency_interval', '60')
+config.set('vars', 'vm_sample_disk_latency_window', '2')
 config.set('vars', 'vm_sample_net_interval', '5')
 config.set('vars', 'vm_sample_net_window', '2')
 
diff --git a/vdsm/libvirtvm.py b/vdsm/libvirtvm.py
index 221589b..4b1fb8b 100644
--- a/vdsm/libvirtvm.py
+++ b/vdsm/libvirtvm.py
@@ -56,12 +56,15 @@ class VmStatsThread(utils.AdvancedStatsThread):
         self.sampleDisk = utils.AdvancedStatsFunction(self._sampleDisk,
                              config.getint('vars',
'vm_sample_disk_interval'),
                              config.getint('vars',
'vm_sample_disk_window'))
+        self.sampleDiskLatency = utils.AdvancedStatsFunction(self._sampleDiskLatency,
+                             config.getint('vars',
'vm_sample_disk_latency_interval'),
+                             config.getint('vars',
'vm_sample_disk_latency_window'))
         self.sampleNet = utils.AdvancedStatsFunction(self._sampleNet,
                              config.getint('vars',
'vm_sample_net_interval'),
                              config.getint('vars',
'vm_sample_net_window'))
 
-        self.addStatsFunction(self.highWrite, self.updateVolumes,
-                            self.sampleCpu, self.sampleDisk, self.sampleNet)
+        self.addStatsFunction(self.highWrite, self.updateVolumes, self.sampleCpu,
+                              self.sampleDisk, self.sampleDiskLatency, self.sampleNet)
 
     def _highWrite(self):
         if self._vm._incomingMigrationPending():
@@ -107,6 +110,17 @@ class VmStatsThread(utils.AdvancedStatsThread):
             diskSamples[vmDrive.name] = self._vm._dom.blockStats(vmDrive.name)
         return diskSamples
 
+    def _sampleDiskLatency(self):
+        if not self._vm._volumesPrepared:
+            # Avoid queries from storage during recovery process
+            return
+
+        diskLatency = {}
+        for vmDrive in self._vm._drives:
+            # Will be done by virDomainQemuMonitor
+            diskLatency[vmDrive.name] = ()
+        return diskLatency
+
     def _sampleNet(self):
         netSamples = {}
         for vmIface in self._vm.interfaces.keys():
@@ -175,6 +189,22 @@ class VmStatsThread(utils.AdvancedStatsThread):
 
             stats[dName] = dStats
 
+    def _getDiskLatency(self, stats):
+        sInfo, eInfo, sampleInterval = self.sampleDiskLatency.getStats()
+
+        for vmDrive in self._vm._drives:
+            dName = vmDrive.name
+
+            dLatency = {'readLatency':  '0.00',
+                        'writeLatency': '0.00',}
+            try:
+                dLatency['readLatency'] = '0.00'
+                dLatency['writeLatency'] = '0.00'
+            except (KeyError, TypeError):
+                self._log.debug("Disk latency not available")
+
+            stats[dName].update(dLatency)
+
     def get(self):
         stats = {}
 
@@ -187,6 +217,7 @@ class VmStatsThread(utils.AdvancedStatsThread):
         self._getCpuStats(stats)
         self._getNetworkStats(stats)
         self._getDiskStats(stats)
+        self._getDiskLatency(stats)
 
         return stats