dashboard, manager, vm: added new scheduler functionality

circle/dashboard/fixtures/node.json

@@ -65,7 +65,10 @@
     "modified": "2014-02-19T21:11:34.671Z", 
     "priority": 1, 
     "traits": [], 
-    "host": 1
+    "host": 1,
+    "ram_weight": 1.0,
+    "cpu_weight": 1.0,
+    "time_stamp":  "2017-12-13T21:08:08.819Z"
   }
 }
 ]

circle/manager/scheduler.py

@@ -67,15 +67,23 @@ def select_node(instance, nodes):
         logger.warning('select_node: no enough RAM for %s', unicode(instance))
         raise NotEnoughMemoryException()
 
-    # sort nodes first by processor usage, then priority
+    # sort nodes first by sorting_key, then priority
     nodes.sort(key=lambda n: n.priority, reverse=True)
-    nodes.sort(key=free_cpu_time, reverse=True)
+    nodes.sort(key=sorting_key, reverse=True)
     result = nodes[0]
 
     logger.info('select_node: %s for %s', unicode(result), unicode(instance))
     return result
 
 
+def sorting_key(node):
+    """Determines how valuable a node is for scheduling.
+    """
+    if free_cpu_time(node) < free_ram(node):
+        return free_cpu_time(node)
+    return free_ram(node)
+
+
 def has_traits(traits, node):
     """True, if the node has all specified traits; otherwise, false.
     """
@@ -116,11 +124,27 @@ def free_cpu_time(node):
     Higher values indicate more idle time.
     """
     try:
-        activity = node.cpu_usage / 100
-        inactivity = 1 - activity
-        cores = node.num_cores
-        return cores * inactivity
+        free_cpu_percent = 1 - node.cpu_usage
+        weight = node.cpu_weight
+        weighted_value = free_cpu_percent * weight
+        return weighted_value
     except TypeError as e:
         logger.warning('Got incorrect monitoring data for node %s. %s',
                        unicode(node), unicode(e))
         return False  # monitoring data is incorrect
+
+
+def free_ram(node):
+    """Get an indicator number for free RAM on the node.
+
+    Higher value indicates more RAM.
+    """
+    try:
+        free_ram_percent = 1 - node.ram_usage
+        weight = node.ram_weight
+        weighted_value = free_ram_percent * weight
+        return weighted_value
+    except TypeError as e:
+        logger.exception('Got incorrect monitoring data for node %s. %s',
+                         unicode(node), unicode(e))
+        return 0

circle/vm/migrations/0003_auto_20171213_2018.py

+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.6 on 2017-12-13 20:18
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.utils.timezone
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('vm', '0002_interface_model'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='node',
+            name='cpu_weight',
+            field=models.FloatField(default=1.0, help_text='Indicates the relative CPU power of this node.', verbose_name='CPU Weight'),
+        ),
+        migrations.AddField(
+            model_name='node',
+            name='ram_weight',
+            field=models.FloatField(default=1.0, help_text='Indicates the relative RAM quantity of this node.', verbose_name='RAM Weight'),
+        ),
+        migrations.AddField(
+            model_name='node',
+            name='time_stamp',
+            field=models.DateTimeField(auto_now_add=True, default=django.utils.timezone.now, help_text='A timestamp for the node, used by the scheduler.', verbose_name='Last Scheduled Time Stamp'),
+            preserve_default=False,
+        ),
+    ]

circle/vm/models/node.py

@@ -30,7 +30,7 @@ from time import time, sleep
 from django.conf import settings
 from django.db.models import (
     CharField, IntegerField, ForeignKey, BooleanField, ManyToManyField,
-    FloatField, permalink, Sum
+    FloatField, DateTimeField, permalink, Sum
 )
 from django.utils import timezone
 from django.utils.translation import ugettext_lazy as _
@@ -128,11 +128,15 @@ class Node(OperatedMixin, TimeStampedModel):
     enabled = BooleanField(verbose_name=_('enabled'), default=False,
                            help_text=_('Indicates whether the node can '
                                        'be used for hosting.'))
-    schedule_enabled = BooleanField(verbose_name=_('schedule enabled'),
-                                    default=False, help_text=_(
-                                        'Indicates whether a vm can be '
-                                        'automatically scheduled to this '
-                                        'node.'))
+    schedule_enabled = BooleanField(
+        verbose_name=_('schedule enabled'),
+        default=False,
+        help_text=_(
+            'Indicates whether a vm can be '
+            'automatically scheduled to this '
+            'node.'
+        )
+    )
     traits = ManyToManyField(Trait, blank=True,
                              help_text=_("Declared traits."),
                              verbose_name=_('traits'))
@@ -140,6 +144,21 @@ class Node(OperatedMixin, TimeStampedModel):
     overcommit = FloatField(default=1.0, verbose_name=_("overcommit ratio"),
                             help_text=_("The ratio of total memory with "
                                         "to without overcommit."))
+    ram_weight = FloatField(
+        default=1.0,
+        help_text=_("Indicates the relative RAM quantity of this node."),
+        verbose_name=_("RAM Weight")
+    )
+    cpu_weight = FloatField(
+        default=1.0,
+        help_text=_("Indicates the relative CPU power of this node."),
+        verbose_name=_("CPU Weight")
+    )
+    time_stamp = DateTimeField(
+        auto_now_add=True,
+        help_text=_("A timestamp for the node, used by the scheduler."),
+        verbose_name=_("Last Scheduled Time Stamp")
+    )
 
     class Meta:
         app_label = 'vm'
@@ -162,7 +181,7 @@ class Node(OperatedMixin, TimeStampedModel):
             self.get_remote_queue_name("vm", "fast")
             self.get_remote_queue_name("vm", "slow")
             self.get_remote_queue_name("net", "fast")
-        except:
+        except Exception:
             return False
         else:
             return True
@@ -353,7 +372,7 @@ class Node(OperatedMixin, TimeStampedModel):
                     continue
 
             return retval
-        except:
+        except Exception:
             logger.exception('Unhandled exception: ')
             return self.remote_query(vm_tasks.get_node_metrics, timeout=30,
                                      priority="fast")
@@ -413,7 +432,7 @@ class Node(OperatedMixin, TimeStampedModel):
             # [{'name': 'cloud-1234', 'state': 'RUNNING', ...}, ...]
             try:
                 id = int(i['name'].split('-')[1])
-            except:
+            except Exception:
                 pass  # name format doesn't match
             else:
                 domains[id] = i['state']