From 5d8431b765a991b8cff4c349c3225f532d015b43 Mon Sep 17 00:00:00 2001
From: Joe Gordon <jogo@cloudscaling.com>
Date: Thu, 21 Jun 2012 16:41:17 -0700
Subject: [PATCH] Fixes ram_allocation_ratio based over subscription
Fix for bug 1016273
Change-Id: I7f7b227e71e93b4bcded150791fb0b9e9df98e4c
(cherry picked from commit 1b40708287808243be27b83791b7d23f8b51b194)
---
doc/source/devref/filter_scheduler.rst | 4 +++-
nova/scheduler/filters/ram_filter.py | 5 ++++-
nova/scheduler/host_manager.py | 2 ++
nova/tests/scheduler/test_host_filters.py | 16 ++++++++++++++--
4 files changed, 23 insertions(+), 4 deletions(-)
diff --git a/doc/source/devref/filter_scheduler.rst b/doc/source/devref/filter_scheduler.rst
index 9f51462..92ee898 100644
--- a/doc/source/devref/filter_scheduler.rst
+++ b/doc/source/devref/filter_scheduler.rst
@@ -58,7 +58,9 @@ code. For example class |RamFilter| has the next realization:
instance_type = filter_properties.get('instance_type')
requested_ram = instance_type['memory_mb']
free_ram_mb = host_state.free_ram_mb
- return free_ram_mb * FLAGS.ram_allocation_ratio >= requested_ram
+ total_usable_ram_mb = host_state.total_usable_ram_mb
+ used_ram_mb = total_usable_ram_mb - free_ram_mb
+ return total_usable_ram_mb * FLAGS.ram_allocation_ratio - used_ram_mb >= requested_ram
Here `ram_allocation_ratio` means the virtual RAM to physical RAM allocation
ratio (it is 1.5 by default). Really, nice and simple.
diff --git a/nova/scheduler/filters/ram_filter.py b/nova/scheduler/filters/ram_filter.py
index 65889d4..4bc84c2 100644
--- a/nova/scheduler/filters/ram_filter.py
+++ b/nova/scheduler/filters/ram_filter.py
@@ -37,4 +37,7 @@ class RamFilter(filters.BaseHostFilter):
instance_type = filter_properties.get('instance_type')
requested_ram = instance_type['memory_mb']
free_ram_mb = host_state.free_ram_mb
- return free_ram_mb * FLAGS.ram_allocation_ratio >= requested_ram
+ total_usable_ram_mb = host_state.total_usable_ram_mb
+ used_ram_mb = total_usable_ram_mb - free_ram_mb
+ return (total_usable_ram_mb * FLAGS.ram_allocation_ratio -
+ used_ram_mb >= requested_ram)
diff --git a/nova/scheduler/host_manager.py b/nova/scheduler/host_manager.py
index f5ba724..289ac27 100644
--- a/nova/scheduler/host_manager.py
+++ b/nova/scheduler/host_manager.py
@@ -124,7 +124,9 @@ class HostState(object):
all_disk_mb -= FLAGS.reserved_host_disk_mb
if FLAGS.reserved_host_memory_mb > 0:
all_ram_mb -= FLAGS.reserved_host_memory_mb
+ #NOTE(jogo) free_ram_mb can be negative
self.free_ram_mb = all_ram_mb
+ self.total_usable_ram_mb = all_ram_mb
self.free_disk_mb = all_disk_mb
self.vcpus_total = vcpus_total
diff --git a/nova/tests/scheduler/test_host_filters.py b/nova/tests/scheduler/test_host_filters.py
index f56a145..19b42fd 100644
--- a/nova/tests/scheduler/test_host_filters.py
+++ b/nova/tests/scheduler/test_host_filters.py
@@ -182,10 +182,22 @@ class HostFiltersTestCase(test.TestCase):
capabilities = {'enabled': True}
service = {'disabled': False}
host = fakes.FakeHostState('host1', 'compute',
- {'free_ram_mb': 1023, 'capabilities': capabilities,
- 'service': service})
+ {'free_ram_mb': 1023, 'total_usable_ram_mb': 1024,
+ 'capabilities': capabilities, 'service': service})
self.assertFalse(filt_cls.host_passes(host, filter_properties))
+ def test_ram_filter_oversubscribe(self):
+ self._stub_service_is_up(True)
+ filt_cls = self.class_map['RamFilter']()
+ self.flags(ram_allocation_ratio=2.0)
+ filter_properties = {'instance_type': {'memory_mb': 1024}}
+ capabilities = {'enabled': True}
+ service = {'disabled': False}
+ host = fakes.FakeHostState('host1', 'compute',
+ {'free_ram_mb': -1024, 'total_usable_ram_mb': 2048,
+ 'capabilities': capabilities, 'service': service})
+ self.assertTrue(filt_cls.host_passes(host, filter_properties))
+
def test_compute_filter_fails_on_service_disabled(self):
self._stub_service_is_up(True)
filt_cls = self.class_map['ComputeFilter']()