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             if self.price is None:
  34                 raise ValueError("Required field 'price' is None")
  35
  36         def meets_constraints(self, **kwargs):
  37             for name, want_value in kwargs.iteritems():
  38                 have_value = getattr(self, name)
  39                 if (have_value != 0) and (have_value < want_value):
  40                     return False
  41             return True
  42
  43
  44     def __init__(self, server_list, max_nodes=None, max_price=None):
  45         self.cloud_sizes = [self.CloudSizeWrapper(s, **kws)
  46                             for s, kws in server_list]
  47         self.cloud_sizes.sort(key=lambda s: s.price)
  48         self.max_nodes = max_nodes or float('inf')
  49         self.max_price = max_price or float('inf')
  50         self.logger = logging.getLogger('arvnodeman.jobqueue')
  51         self.logged_jobs = set()
  52
  53     @staticmethod
  54     def coerce_int(x, fallback):
  55         try:
  56             return int(x)
  57         except (TypeError, ValueError):
  58             return fallback
  59
  60     def cloud_size_for_constraints(self, constraints):
  61         want_value = lambda key: self.coerce_int(constraints.get(key), 0)
  62         wants = {'cores': want_value('min_cores_per_node'),
  63                  'ram': want_value('min_ram_mb_per_node'),
  64                  'scratch': want_value('min_scratch_mb_per_node')}
  65         for size in self.cloud_sizes:
  66             if size.meets_constraints(**wants):
  67                 return size
  68         return None
  69
  70     def servers_for_queue(self, queue):
  71         servers = []
  72         seen_jobs = set()
  73         for job in queue:
  74             seen_jobs.add(job['uuid'])
  75             constraints = job['runtime_constraints']
  76             want_count = max(1, self.coerce_int(constraints.get('min_nodes'), 1))
  77             cloud_size = self.cloud_size_for_constraints(constraints)
  78             if cloud_size is None:
  79                 if job['uuid'] not in self.logged_jobs:
  80                     self.logged_jobs.add(job['uuid'])
  81                     self.logger.debug("job %s not satisfiable", job['uuid'])
  82             elif (want_count <= self.max_nodes) and (want_count*cloud_size.price <= self.max_price):
  83                 servers.extend([cloud_size.real] * want_count)
  84         self.logged_jobs.intersection_update(seen_jobs)
  85         return servers
  86
  87     def cheapest_size(self):
  88         return self.cloud_sizes[0]
  89
  90     def find_size(self, sizeid):
  91         for s in self.cloud_sizes:
  92             if s.id == sizeid:
  93                 return s
  94         return None
  95
  96 class JobQueueMonitorActor(clientactor.RemotePollLoopActor):
  97     """Actor to generate server wishlists from the job queue.
  98
  99     This actor regularly polls Arvados' job queue, and uses the provided
 100     ServerCalculator to turn that into a list of requested node sizes.  That
 101     list is sent to subscribers on every poll.
 102     """
 103
 104     CLIENT_ERRORS = ARVADOS_ERRORS
 105     LOGGER_NAME = 'arvnodeman.jobqueue'
 106
 107     def __init__(self, client, timer_actor, server_calc, *args, **kwargs):
 108         super(JobQueueMonitorActor, self).__init__(
 109             client, timer_actor, *args, **kwargs)
 110         self._calculator = server_calc
 111
 112     def _send_request(self):
 113         return self._client.jobs().queue().execute()['items']
 114
 115     def _got_response(self, queue):
 116         server_list = self._calculator.servers_for_queue(queue)
 117         self._logger.debug("Sending server wishlist: %s",
 118                            ', '.join(s.name for s in server_list) or "(empty)")
 119         return super(JobQueueMonitorActor, self)._got_response(server_list)