lifetime.
"""
- def __init__(self, max_cu=32, max_mu=1024):
+ def __init__(self, max_cu=32, max_mu=1024,
+ deactivate_cpu_limit=False,
+ deactivate_mem_limit=False):
"""
Initialize model.
:param max_cu: Maximum number of compute units available in this DC.
self.dc_max_cu = max_cu
self.dc_max_mu = max_mu
self.dc_alloc_cu = 0
+ self.dc_alloc_mu = 0
+ self.deactivate_cpu_limit = deactivate_cpu_limit
+ self.deactivate_mem_limit = deactivate_mem_limit
super(self.__class__, self).__init__()
- def allocate(self, name, flavor_name):
+ def allocate(self, d):
"""
- Calculate resources for container with given flavor.
- :param name: Container name.
- :param flavor_name: Flavor name.
+ Allocate resources for the given container.
+ Defined by d.flavor_name
+ :param d: container
:return:
"""
- # TODO Add memory model calculation (split in private methods for each tuple component)
- # bookkeeping and flavor handling
- if flavor_name not in self._flavors:
- raise Exception("Flavor %r does not exist" % flavor_name)
- fl = self._flavors.get(flavor_name)
- fl_cu = fl.get("compute")
- self.allocated_compute_instances[name] = flavor_name
+ self._allocated_compute_instances[d.name] = d
+ if not self.deactivate_cpu_limit:
+ self._allocate_cpu(d)
+ if not self.deactivate_mem_limit:
+ self._allocate_mem(d)
+ self._apply_limits()
+
+ def _allocate_cpu(self, d):
+ """
+ Actually allocate (bookkeeping)
+ :param d: container
+ :return:
+ """
+ fl_cu = self._get_flavor(d).get("compute")
# check for over provisioning
if self.dc_alloc_cu + fl_cu > self.dc_max_cu:
raise Exception("Not enough compute resources left.")
self.dc_alloc_cu += fl_cu
- #
- # calculate cpu limitation:
- #
+
+ def _allocate_mem(self, d):
+ """
+ Actually allocate (bookkeeping)
+ :param d: container
+ :return:
+ """
+ fl_mu = self._get_flavor(d).get("memory")
+ # check for over provisioning
+ if self.dc_alloc_mu + fl_mu > self.dc_max_mu:
+ raise Exception("Not enough memory resources left.")
+ self.dc_alloc_mu += fl_mu
+
+ def free(self, d):
+ """
+ Free resources allocated to the given container.
+ :param d: container
+ :return:
+ """
+ del self._allocated_compute_instances[d.name]
+ if not self.deactivate_cpu_limit:
+ self._free_cpu(d)
+ if not self.deactivate_mem_limit:
+ self._free_mem(d)
+ self._apply_limits()
+
+ def _free_cpu(self, d):
+ """
+ Free resources.
+ :param d: container
+ :return:
+ """
+ self.dc_alloc_cu -= self._get_flavor(d).get("compute")
+
+ def _free_mem(self, d):
+ """
+ Free resources.
+ :param d: container
+ :return:
+ """
+ self.dc_alloc_mu -= self._get_flavor(d).get("memory")
+
+ def _apply_limits(self):
+ """
+ Recalculate real resource limits for all allocated containers and apply them
+ to their cgroups.
+ We have to recalculate for all to allow e.g. overprovisioning models.
+ :return:
+ """
+ for d in self._allocated_compute_instances.itervalues():
+ if not self.deactivate_cpu_limit:
+ self._apply_cpu_limits(d)
+ if not self.deactivate_mem_limit:
+ self._apply_mem_limits(d)
+
+ def _apply_cpu_limits(self, d):
+ """
+ Calculate real CPU limit (CFS bandwidth) and apply.
+ :param d: container
+ :return:
+ """
+ number_cu = self._get_flavor(d).get("compute")
# get cpu time fraction for entire emulation
e_cpu = self.registrar.e_cpu
# calculate cpu time fraction of a single compute unit
- cu = e_cpu / sum([rm.dc_max_cu for rm in list(self.registrar.resource_models)])
+ single_cu = float(e_cpu) / sum([rm.dc_max_cu for rm in list(self.registrar.resource_models)])
# calculate cpu time fraction for container with given flavor
- c_ct = cu * fl_cu
- return c_ct, -1.0, -1.0 # return 3tuple (cpu, memory, disk)
+ cpu_time_percentage = single_cu * number_cu
+ # calculate cpu period and quota for CFS
+ # (see: https://www.kernel.org/doc/Documentation/scheduler/sched-bwc.txt)
+ # Attention minimum cpu_quota is 1ms (micro)
+ cpu_period = 1000000 # lets consider a fixed period of 1000000 microseconds for now
+ cpu_quota = cpu_period * cpu_time_percentage # calculate the fraction of cpu time for this container
+ # ATTENTION >= 1000 to avoid a invalid argument system error ... no idea why
+ if cpu_quota < 1000:
+ cpu_quota = 1000
+ LOG.warning("Increased CPU quota for %r to avoid system error." % d.name)
+ # apply to container if changed
+ if d.cpu_period != cpu_period or d.cpu_quota != cpu_quota:
+ LOG.debug("Setting CPU limit for %r: cpu_quota = cpu_period * limit = %f * %f = %f" % (
+ d.name, cpu_period, cpu_time_percentage, cpu_quota))
+ d.updateCpuLimit(cpu_period=int(cpu_period), cpu_quota=int(cpu_quota))
+
+ def _apply_mem_limits(self, d):
+ """
+ Calculate real mem limit and apply.
+ :param d: container
+ :return:
+ """
+ number_mu = self._get_flavor(d).get("memory")
+ # get memory amount for entire emulation
+ e_mem = self.registrar.e_mem
+ # calculate amount of memory for a single mu
+ single_mu = float(e_mem) / sum([rm.dc_max_mu for rm in list(self.registrar.resource_models)])
+ # calculate mem for given flavor
+ mem_limit = single_mu * number_mu
+ # ATTENTION minimum mem_limit per container is 4MB
+ if mem_limit < 4:
+ mem_limit = 4
+ LOG.warning("Increased MEM limit for %r because it was less than 4.0 MB." % name)
+ # to byte!
+ mem_limit = int(mem_limit*1024*1024)
+ # apply to container if changed
+ if d.mem_limit != mem_limit:
+ LOG.debug("Setting MEM limit for %r: mem_limit = %f MB" % (d.name, mem_limit/1024/1024))
+ d.updateMemoryLimit(mem_limit=mem_limit)
+
+ def get_state_dict(self):
+ """
+ Return the state of the resource model as simple dict.
+ Helper method for logging functionality.
+ :return:
+ """
+ # TODO update
+ r = dict()
+ r["e_cpu"] = self.registrar.e_cpu
+ r["e_mem"] = self.registrar.e_mem
+ r["dc_max_cu"] = self.dc_max_cu
+ r["dc_max_mu"] = self.dc_max_mu
+ r["dc_alloc_cu"] = self.dc_alloc_cu
+ r["dc_alloc_mu"] = self.dc_alloc_mu
+ r["cu_cpu_percentage"] = -1
+ r["mu_mem_percentage"] = -1
+ r["allocated_compute_instances"] = None #self._allocated_compute_instances
+ return r
- def free(self, name):
+ def _get_flavor(self, d):
"""
- Free resources of given container.
- :param name: Container name.
+ Get flavor assigned to given container.
+ Identified by d.flavor_name.
+ :param d: container
:return:
"""
- if name not in self.allocated_compute_instances:
- return False
- # bookkeeping
- self.dc_alloc_cu -= self._flavors.get(self.allocated_compute_instances[name]).get("compute")
- del self.allocated_compute_instances[name]
- # we don't have to calculate anything special here in this simple model
- return True
+ if d.flavor_name not in self._flavors:
+ raise Exception("Flavor %r does not exist" % d.flavor_name)
+ return self._flavors.get(d.flavor_name)