diff options
Diffstat (limited to 'nova/scheduler/filters/ram_filter.py')
| -rw-r--r-- | nova/scheduler/filters/ram_filter.py | 60 |
1 files changed, 55 insertions, 5 deletions
diff --git a/nova/scheduler/filters/ram_filter.py b/nova/scheduler/filters/ram_filter.py index 7e20e3d15..ed601ec32 100644 --- a/nova/scheduler/filters/ram_filter.py +++ b/nova/scheduler/filters/ram_filter.py @@ -16,21 +16,27 @@ from oslo.config import cfg +from nova import db from nova.openstack.common import log as logging from nova.scheduler import filters LOG = logging.getLogger(__name__) -ram_allocation_ratio_opt = cfg.FloatOpt("ram_allocation_ratio", +ram_allocation_ratio_opt = cfg.FloatOpt('ram_allocation_ratio', default=1.5, - help="virtual ram to physical ram allocation ratio") + help='Virtual ram to physical ram allocation ratio which affects ' + 'all ram filters. This configuration specifies a global ratio ' + 'for RamFilter. For AggregateRamFilter, it will fall back to ' + 'this configuration value if no per-aggregate setting found.') CONF = cfg.CONF CONF.register_opt(ram_allocation_ratio_opt) -class RamFilter(filters.BaseHostFilter): - """Ram Filter with over subscription flag.""" +class BaseRamFilter(filters.BaseHostFilter): + + def _get_ram_allocation_ratio(self, host_state, filter_properties): + raise NotImplementedError def host_passes(self, host_state, filter_properties): """Only return hosts with sufficient available RAM.""" @@ -39,7 +45,10 @@ class RamFilter(filters.BaseHostFilter): free_ram_mb = host_state.free_ram_mb total_usable_ram_mb = host_state.total_usable_ram_mb - memory_mb_limit = total_usable_ram_mb * CONF.ram_allocation_ratio + ram_allocation_ratio = self._get_ram_allocation_ratio(host_state, + filter_properties) + + memory_mb_limit = total_usable_ram_mb * ram_allocation_ratio used_ram_mb = total_usable_ram_mb - free_ram_mb usable_ram = memory_mb_limit - used_ram_mb if not usable_ram >= requested_ram: @@ -53,3 +62,44 @@ class RamFilter(filters.BaseHostFilter): # save oversubscription limit for compute node to test against: host_state.limits['memory_mb'] = memory_mb_limit return True + + +class RamFilter(BaseRamFilter): + """Ram Filter with over subscription flag.""" + + def _get_ram_allocation_ratio(self, host_state, filter_properties): + return CONF.ram_allocation_ratio + + +class AggregateRamFilter(BaseRamFilter): + """AggregateRamFilter with per-aggregate ram subscription flag. + + Fall back to global ram_allocation_ratio if no per-aggregate setting found. + """ + + def _get_ram_allocation_ratio(self, host_state, filter_properties): + context = filter_properties['context'].elevated() + # TODO(uni): DB query in filter is a performance hit, especially for + # system with lots of hosts. Will need a general solution here to fix + # all filters with aggregate DB call things. + metadata = db.aggregate_metadata_get_by_host( + context, host_state.host, key='ram_allocation_ratio') + aggregate_vals = metadata.get('ram_allocation_ratio', set()) + num_values = len(aggregate_vals) + + if num_values == 0: + return CONF.ram_allocation_ratio + + if num_values > 1: + LOG.warning(_("%(num_values)d ratio values found, " + "of which the minimum value will be used."), + {'num_values': num_values}) + + try: + ratio = float(min(aggregate_vals)) + except ValueError as e: + LOG.warning(_("Could not decode ram_allocation_ratio: " + "'%(e)s'") % locals()) + ratio = CONF.ram_allocation_ratio + + return ratio |