[Kimchi-devel] [PATCH 1/2] Update stats when looking up one single VM

[Crístian Deives]

The VM stats are updated only when all VMs are looked up (i.e.
'GET /vms'). If only one VM is looked up (i.e. 'GET /vms/myvm'), that
request returns the values cached previously. This behavior doesn't
allow the user to get fresh stat values unless all VM stats
are requested.

Fetch the VM stats when looking up one single VM, not only when looking
up all VMs.

Signed-off-by: Crístian Deives <cristiandeives at gmail.com>
---
 src/kimchi/model/vms.py | 48 +++++++++++++++++++++++-------------------------
 1 file changed, 23 insertions(+), 25 deletions(-)

diff --git a/src/kimchi/model/vms.py b/src/kimchi/model/vms.py
index af5e765..9c1f308 100644
--- a/src/kimchi/model/vms.py
+++ b/src/kimchi/model/vms.py
@@ -83,35 +83,33 @@ class VMsModel(object):
         self.caps = CapabilitiesModel(**kargs)
 
     @staticmethod
-    def _update_guests_stats(names, conn):
-        for name in names:
-            try:
-                dom = VMModel.get_vm(name, conn)
+    def _update_guest_stats(name, conn):
+        try:
+            dom = VMModel.get_vm(name, conn)
 
-                vm_uuid = dom.UUIDString()
-                info = dom.info()
-                state = DOM_STATE_MAP[info[0]]
+            vm_uuid = dom.UUIDString()
+            info = dom.info()
+            state = DOM_STATE_MAP[info[0]]
 
-                if state != 'running':
-                    stats[vm_uuid] = {}
-                    continue
+            if state != 'running':
+                stats[vm_uuid] = {}
+                return
 
-                if stats.get(vm_uuid, None) is None:
-                    stats[vm_uuid] = {}
+            if stats.get(vm_uuid, None) is None:
+                stats[vm_uuid] = {}
 
-                timestamp = time.time()
-                prevStats = stats.get(vm_uuid, {})
-                seconds = timestamp - prevStats.get('timestamp', 0)
-                stats[vm_uuid].update({'timestamp': timestamp})
+            timestamp = time.time()
+            prevStats = stats.get(vm_uuid, {})
+            seconds = timestamp - prevStats.get('timestamp', 0)
+            stats[vm_uuid].update({'timestamp': timestamp})
 
-                VMsModel._get_percentage_cpu_usage(vm_uuid, info, seconds)
-                VMsModel._get_network_io_rate(vm_uuid, dom, seconds)
-                VMsModel._get_disk_io_rate(vm_uuid, dom, seconds)
-            except Exception as e:
-                # VM might be deleted just after we get the list.
-                # This is OK, just skip.
-                kimchi_log.debug('Error processing VM stats: %s', e.message)
-                continue
+            VMsModel._get_percentage_cpu_usage(vm_uuid, info, seconds)
+            VMsModel._get_network_io_rate(vm_uuid, dom, seconds)
+            VMsModel._get_disk_io_rate(vm_uuid, dom, seconds)
+        except Exception as e:
+            # VM might be deleted just after we get the list.
+            # This is OK, just skip.
+            kimchi_log.debug('Error processing VM stats: %s', e.message)
 
     @staticmethod
     def _get_percentage_cpu_usage(vm_uuid, info, seconds):
@@ -255,7 +253,6 @@ class VMsModel(object):
         conn_ = conn.get()
         names = [dom.name().decode('utf-8') for dom in conn_.listAllDomains(0)]
         names = sorted(names, key=unicode.lower)
-        VMsModel._update_guests_stats(names, conn)
         return names
 
 
@@ -822,6 +819,7 @@ class VMModel(object):
                 extra_info = {}
         icon = extra_info.get('icon')
 
+        VMsModel._update_guest_stats(name, self.conn.get())
         vm_stats = stats.get(dom.UUIDString(), {})
         res = {}
         res['cpu_utilization'] = vm_stats.get('cpu', 0)
-- 
2.1.0