[Kimchi-devel] [PATCH] Guest memory utilization.

[pvital at linux.vnet.ibm.com]

From: Paulo Vital <pvital at linux.vnet.ibm.com>

Add support to capture the guest's memory utilization by using libvirt
'virDomainMemoryStats'. The return is the percentage of memory utilization
in the guest's stats dictionary.

Signed-off-by: Paulo Vital <pvital at linux.vnet.ibm.com>
---
 src/wok/plugins/kimchi/docs/API.md             |  2 ++
 src/wok/plugins/kimchi/model/vms.py            | 15 +++++++++++++++
 src/wok/plugins/kimchi/tests/test_mockmodel.py |  2 +-
 src/wok/plugins/kimchi/tests/test_model.py     |  2 +-
 4 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/wok/plugins/kimchi/docs/API.md b/src/wok/plugins/kimchi/docs/API.md
index a9333b5..eb3905f 100644
--- a/src/wok/plugins/kimchi/docs/API.md
+++ b/src/wok/plugins/kimchi/docs/API.md
@@ -107,6 +107,8 @@ server.
     * stats: Virtual machine statistics:
         * cpu_utilization: A number between 0 and 100 which indicates the
           percentage of CPU utilization.
+        * mem_utilization: A number between 0 and 100 which indicates the
+          percentage of memory utilization.
         * net_throughput: Expresses total network throughput for reads and
           writes across all virtual interfaces (kb/s).
         * net_throughput_peak: The highest recent value of 'net_throughput'.
diff --git a/src/wok/plugins/kimchi/model/vms.py b/src/wok/plugins/kimchi/model/vms.py
index 60145d0..6e77bae 100644
--- a/src/wok/plugins/kimchi/model/vms.py
+++ b/src/wok/plugins/kimchi/model/vms.py
@@ -896,6 +896,7 @@ class VMModel(object):
             self.stats[vm_uuid].update({'timestamp': timestamp})
 
             self._get_percentage_cpu_usage(vm_uuid, info, seconds)
+            self._get_percentage_mem_usage(vm_uuid, dom, seconds)
             self._get_network_io_rate(vm_uuid, dom, seconds)
             self._get_disk_io_rate(vm_uuid, dom, seconds)
         except Exception as e:
@@ -914,6 +915,19 @@ class VMModel(object):
 
         self.stats[vm_uuid].update({'cputime': info[4], 'cpu': percentage})
 
+    def _get_percentage_mem_usage(self, vm_uuid, dom, seconds):
+        # Get the guest's memory stats
+        memStats = dom.memoryStats()
+        if memStats:
+            memUsed = memStats.get('available') - memStats.get('unused')
+        else:
+            wok_log.debug('Failed to measure memory usage of the guest.')
+
+        percentage = max(0.0, min(100.0, ((memUsed * 100.0) /
+                                          memStats.get('available'))))
+
+        self.stats[vm_uuid].update({'mem_usage': percentage})
+
     def _get_network_io_rate(self, vm_uuid, dom, seconds):
         prevNetRxKB = self.stats[vm_uuid].get('netRxKB', 0)
         prevNetTxKB = self.stats[vm_uuid].get('netTxKB', 0)
@@ -1000,6 +1014,7 @@ class VMModel(object):
         vm_stats = self.stats.get(dom.UUIDString(), {})
         res = {}
         res['cpu_utilization'] = vm_stats.get('cpu', 0)
+        res['mem_utilization'] = vm_stats.get('mem_usage', 0)
         res['net_throughput'] = vm_stats.get('net_io', 0)
         res['net_throughput_peak'] = vm_stats.get('max_net_io', 100)
         res['io_throughput'] = vm_stats.get('disk_io', 0)
diff --git a/src/wok/plugins/kimchi/tests/test_mockmodel.py b/src/wok/plugins/kimchi/tests/test_mockmodel.py
index 54a1ac8..7c914b8 100644
--- a/src/wok/plugins/kimchi/tests/test_mockmodel.py
+++ b/src/wok/plugins/kimchi/tests/test_mockmodel.py
@@ -125,7 +125,7 @@ class MockModelTests(unittest.TestCase):
                     'screenshot', 'icon', 'graphics', 'users', 'groups',
                     'access', 'persistent'))
 
-        stats_keys = set(('cpu_utilization',
+        stats_keys = set(('cpu_utilization', 'mem_utilization',
                           'net_throughput', 'net_throughput_peak',
                           'io_throughput', 'io_throughput_peak'))
 
diff --git a/src/wok/plugins/kimchi/tests/test_model.py b/src/wok/plugins/kimchi/tests/test_model.py
index 4ae837c..fdbe3b4 100644
--- a/src/wok/plugins/kimchi/tests/test_model.py
+++ b/src/wok/plugins/kimchi/tests/test_model.py
@@ -95,7 +95,7 @@ class ModelTests(unittest.TestCase):
                     'screenshot', 'icon', 'graphics', 'users', 'groups',
                     'access', 'persistent'))
 
-        stats_keys = set(('cpu_utilization',
+        stats_keys = set(('cpu_utilization', 'mem_utilization',
                           'net_throughput', 'net_throughput_peak',
                           'io_throughput', 'io_throughput_peak'))
         info = inst.vm_lookup('test')
-- 
2.4.3