services/nodemanager/arvnodeman/jobqueue.py

   1 #!/usr/bin/env python
   2
   3 from __future__ import absolute_import, print_function
   4
   5 import logging
   6
   7 from . import clientactor
   8 from .config import ARVADOS_ERRORS
   9
  10 class ServerCalculator(object):
  11     """Generate cloud server wishlists from an Arvados job queue.
  12
  13     Instantiate this class with a list of cloud node sizes you're willing to
  14     use, plus keyword overrides from the configuration.  Then you can pass
  15     job queues to servers_for_queue.  It will return a list of node sizes
  16     that would best satisfy the jobs, choosing the cheapest size that
  17     satisfies each job, and ignoring jobs that can't be satisfied.
  18     """
  19
  20     class CloudSizeWrapper(object):
  21         def __init__(self, real_size, **kwargs):
  22             self.real = real_size
  23             for name in ['id', 'name', 'ram', 'disk', 'bandwidth', 'price',
  24                          'extra']:
  25                 setattr(self, name, getattr(self.real, name))
  26             self.cores = kwargs.pop('cores')
  27             self.scratch = self.disk
  28             for name, override in kwargs.iteritems():
  29                 if not hasattr(self, name):
  30                     raise ValueError("unrecognized size field '%s'" % (name,))
  31                 setattr(self, name, override)
  32
  33         def meets_constraints(self, **kwargs):
  34             for name, want_value in kwargs.iteritems():
  35                 have_value = getattr(self, name)
  36                 if (have_value != 0) and (have_value < want_value):
  37                     return False
  38             return True
  39
  40
  41     def __init__(self, server_list, max_nodes=None, max_price=None):
  42         self.cloud_sizes = [self.CloudSizeWrapper(s, **kws)
  43                             for s, kws in server_list]
  44         self.cloud_sizes.sort(key=lambda s: s.price)
  45         self.max_nodes = max_nodes or float('inf')
  46         self.max_price = max_price or float('inf')
  47         self.logger = logging.getLogger('arvnodeman.jobqueue')
  48         self.logged_jobs = set()
  49
  50     @staticmethod
  51     def coerce_int(x, fallback):
  52         try:
  53             return int(x)
  54         except (TypeError, ValueError):
  55             return fallback
  56
  57     def cloud_size_for_constraints(self, constraints):
  58         want_value = lambda key: self.coerce_int(constraints.get(key), 0)
  59         wants = {'cores': want_value('min_cores_per_node'),
  60                  'ram': want_value('min_ram_mb_per_node'),
  61                  'scratch': want_value('min_scratch_mb_per_node')}
  62         for size in self.cloud_sizes:
  63             if size.meets_constraints(**wants):
  64                 return size
  65         return None
  66
  67     def servers_for_queue(self, queue):
  68         servers = []
  69         seen_jobs = set()
  70         for job in queue:
  71             seen_jobs.add(job['uuid'])
  72             constraints = job['runtime_constraints']
  73             want_count = self.coerce_int(constraints.get('min_nodes'), 1)
  74             cloud_size = self.cloud_size_for_constraints(constraints)
  75             if cloud_size is None:
  76                 if job['uuid'] not in self.logged_jobs:
  77                     self.logged_jobs.add(job['uuid'])
  78                     self.logger.debug("job %s not satisfiable", job['uuid'])
  79             elif (want_count <= self.max_nodes) and (want_count*cloud_size.price <= self.max_price):
  80                 servers.extend([cloud_size.real] * max(1, want_count))
  81         self.logged_jobs.intersection_update(seen_jobs)
  82         return servers
  83
  84     def cheapest_size(self):
  85         return self.cloud_sizes[0]
  86
  87
  88 class JobQueueMonitorActor(clientactor.RemotePollLoopActor):
  89     """Actor to generate server wishlists from the job queue.
  90
  91     This actor regularly polls Arvados' job queue, and uses the provided
  92     ServerCalculator to turn that into a list of requested node sizes.  That
  93     list is sent to subscribers on every poll.
  94     """
  95
  96     CLIENT_ERRORS = ARVADOS_ERRORS
  97     LOGGER_NAME = 'arvnodeman.jobqueue'
  98
  99     def __init__(self, client, timer_actor, server_calc, *args, **kwargs):
 100         super(JobQueueMonitorActor, self).__init__(
 101             client, timer_actor, *args, **kwargs)
 102         self._calculator = server_calc
 103
 104     def _send_request(self):
 105         return self._client.jobs().queue().execute()['items']
 106
 107     def _got_response(self, queue):
 108         server_list = self._calculator.servers_for_queue(queue)
 109         self._logger.debug("Sending server wishlist: %s",
 110                            ', '.join(s.name for s in server_list) or "(empty)")
 111         return super(JobQueueMonitorActor, self)._got_response(server_list)