Files
mayan-edms/apps/clustering/models.py
Roberto Rosario 8f714a9fa9 Add reminder
2012-08-01 01:46:09 -04:00

90 lines
2.8 KiB
Python

from __future__ import absolute_import
import os
import datetime
import platform
import psutil
from django.db import models, IntegrityError, transaction
from django.db import close_connection
from django.utils.translation import ugettext_lazy as _
from django.utils.translation import ugettext
from common.models import Singleton
DEFAULT_NODE_TTL = 5
DEFAULT_NODE_HEARTBEAT_INTERVAL = 1
class NodeManager(models.Manager):
def myself(self):
node, created = self.model.objects.get_or_create(hostname=platform.node())
node.refresh()
if created:
# Store the refresh data because is a new instance
node.save()
return node
class Node(models.Model):
hostname = models.CharField(max_length=255, verbose_name=_(u'hostname'))
cpuload = models.FloatField(blank=True, default=0.0, verbose_name=_(u'cpu load'))
heartbeat = models.DateTimeField(blank=True, default=datetime.datetime.now(), verbose_name=_(u'last heartbeat check'))
memory_usage = models.FloatField(blank=True, default=0.0, verbose_name=_(u'memory usage'))
objects = NodeManager()
@classmethod
def platform_info(cls):
return {
'cpuload': psutil.cpu_percent(),
'memory_usage': psutil.phymem_usage().percent
}
def __unicode__(self):
return self.hostname
def refresh(self):
if self.hostname == platform.node():
# Make we can only update ourselves
info = Node.platform_info()
self.cpuload = info['cpuload']
self.memory_usage = info['memory_usage']
def save(self, *args, **kwargs):
self.heartbeat = datetime.datetime.now()
return super(Node, self).save(*args, **kwargs)
class Meta:
verbose_name = _(u'node')
verbose_name_plural = _(u'nodes')
class ClusteringConfigManager(models.Manager):
def dead_nodes(self):
return Node.objects.filter(heartbeat__lt=datetime.datetime.now() - datetime.timedelta(seconds=self.model.get().node_time_to_live))
def delete_dead_nodes(self):
self.dead_nodes().delete()
def zombiest_node(self):
try:
return self.dead_nodes().order_by('-heartbeat')[0]
except IndexError:
return None
class ClusteringConfig(Singleton):
node_time_to_live = models.PositiveIntegerField(verbose_name=(u'time to live (in seconds)'), default=DEFAULT_NODE_TTL) # After this time a worker is considered dead
node_heartbeat_interval = models.PositiveIntegerField(verbose_name=(u'heartbeat interval'), default=DEFAULT_NODE_HEARTBEAT_INTERVAL)
# TODO: add validation, interval cannot be greater than TTL
objects = ClusteringConfigManager()
def __unicode__(self):
return ugettext('clustering config')
class Meta:
verbose_name = verbose_name_plural = _(u'clustering config')