root / snf-cyclades-app / synnefo / logic / backend_allocator.py @ ad297723
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1 | cc7c0f44 | Christos Stavrakakis | # Copyright 2011 GRNET S.A. All rights reserved.
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2 | cc7c0f44 | Christos Stavrakakis | #
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3 | cc7c0f44 | Christos Stavrakakis | # Redistribution and use in source and binary forms, with or without
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4 | cc7c0f44 | Christos Stavrakakis | # modification, are permitted provided that the following conditions
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5 | cc7c0f44 | Christos Stavrakakis | # are met:
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6 | cc7c0f44 | Christos Stavrakakis | #
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7 | cc7c0f44 | Christos Stavrakakis | # 1. Redistributions of source code must retain the above copyright
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8 | cc7c0f44 | Christos Stavrakakis | # notice, this list of conditions and the following disclaimer.
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9 | cc7c0f44 | Christos Stavrakakis | #
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10 | cc7c0f44 | Christos Stavrakakis | # 2. Redistributions in binary form must reproduce the above copyright
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11 | cc7c0f44 | Christos Stavrakakis | # notice, this list of conditions and the following disclaimer in the
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12 | cc7c0f44 | Christos Stavrakakis | # documentation and/or other materials provided with the distribution.
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13 | cc7c0f44 | Christos Stavrakakis | #
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14 | cc7c0f44 | Christos Stavrakakis | # THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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15 | cc7c0f44 | Christos Stavrakakis | # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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16 | cc7c0f44 | Christos Stavrakakis | # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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17 | cc7c0f44 | Christos Stavrakakis | # ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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18 | cc7c0f44 | Christos Stavrakakis | # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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19 | cc7c0f44 | Christos Stavrakakis | # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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20 | cc7c0f44 | Christos Stavrakakis | # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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21 | cc7c0f44 | Christos Stavrakakis | # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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22 | cc7c0f44 | Christos Stavrakakis | # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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23 | cc7c0f44 | Christos Stavrakakis | # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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24 | cc7c0f44 | Christos Stavrakakis | # SUCH DAMAGE.
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25 | cc7c0f44 | Christos Stavrakakis | #
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26 | cc7c0f44 | Christos Stavrakakis | # The views and conclusions contained in the software and documentation are
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27 | cc7c0f44 | Christos Stavrakakis | # those of the authors and should not be interpreted as representing official
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28 | cc7c0f44 | Christos Stavrakakis | # policies, either expressed or implied, of GRNET S.A.
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29 | cc7c0f44 | Christos Stavrakakis | |
30 | cc7c0f44 | Christos Stavrakakis | import datetime |
31 | cc7c0f44 | Christos Stavrakakis | from django.utils import importlib |
32 | cc7c0f44 | Christos Stavrakakis | |
33 | cc7c0f44 | Christos Stavrakakis | from synnefo import settings |
34 | cc7c0f44 | Christos Stavrakakis | from synnefo.db.models import Backend |
35 | cc7c0f44 | Christos Stavrakakis | from synnefo.logic.backend import update_resources |
36 | cc7c0f44 | Christos Stavrakakis | |
37 | cc7c0f44 | Christos Stavrakakis | |
38 | cc7c0f44 | Christos Stavrakakis | class BackendAllocator(): |
39 | cc7c0f44 | Christos Stavrakakis | """Wrapper class for instance allocation.
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40 | cc7c0f44 | Christos Stavrakakis |
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41 | cc7c0f44 | Christos Stavrakakis | """
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42 | cc7c0f44 | Christos Stavrakakis | def __init__(self): |
43 | cc7c0f44 | Christos Stavrakakis | self.strategy_mod =\
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44 | cc7c0f44 | Christos Stavrakakis | importlib.import_module(settings.BACKEND_ALLOCATOR_MODULE) |
45 | cc7c0f44 | Christos Stavrakakis | |
46 | cc7c0f44 | Christos Stavrakakis | def allocate(self, flavor): |
47 | cc7c0f44 | Christos Stavrakakis | # Get the size of the vm
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48 | cc7c0f44 | Christos Stavrakakis | disk = flavor_disk(flavor) |
49 | cc7c0f44 | Christos Stavrakakis | ram = flavor.ram |
50 | cc7c0f44 | Christos Stavrakakis | cpu = flavor.cpu |
51 | cc7c0f44 | Christos Stavrakakis | vm = {'ram': ram, 'disk': disk, 'cpu': cpu} |
52 | cc7c0f44 | Christos Stavrakakis | |
53 | cc7c0f44 | Christos Stavrakakis | # Refresh backends, if needed
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54 | cc7c0f44 | Christos Stavrakakis | refresh_backends_stats() |
55 | cc7c0f44 | Christos Stavrakakis | |
56 | cc7c0f44 | Christos Stavrakakis | # Get available backends
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57 | cc7c0f44 | Christos Stavrakakis | available_backends = get_available_backends() |
58 | cc7c0f44 | Christos Stavrakakis | |
59 | cc7c0f44 | Christos Stavrakakis | if not available_backends: |
60 | cc7c0f44 | Christos Stavrakakis | return None |
61 | cc7c0f44 | Christos Stavrakakis | |
62 | cc7c0f44 | Christos Stavrakakis | # Find the best backend to host the vm, based on the allocation
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63 | cc7c0f44 | Christos Stavrakakis | # strategy
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64 | cc7c0f44 | Christos Stavrakakis | backend_id = self.strategy_mod.allocate(available_backends, vm)
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65 | cc7c0f44 | Christos Stavrakakis | |
66 | cc7c0f44 | Christos Stavrakakis | backend = Backend.objects.get(id=backend_id) |
67 | cc7c0f44 | Christos Stavrakakis | # Reduce the free resources of the selected backend by the size of
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68 | cc7c0f44 | Christos Stavrakakis | # the vm
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69 | cc7c0f44 | Christos Stavrakakis | reduce_backend_resources(backend, vm) |
70 | cc7c0f44 | Christos Stavrakakis | |
71 | cc7c0f44 | Christos Stavrakakis | return backend
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72 | cc7c0f44 | Christos Stavrakakis | |
73 | cc7c0f44 | Christos Stavrakakis | |
74 | cc7c0f44 | Christos Stavrakakis | def get_available_backends(): |
75 | cc7c0f44 | Christos Stavrakakis | """Get available backends from db.
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76 | cc7c0f44 | Christos Stavrakakis |
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77 | cc7c0f44 | Christos Stavrakakis | """
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78 | cc7c0f44 | Christos Stavrakakis | attrs = ['mfree', 'mtotal', 'dfree', 'dtotal', 'pinst_cnt', 'ctotal'] |
79 | cc7c0f44 | Christos Stavrakakis | backends = {} |
80 | cc7c0f44 | Christos Stavrakakis | for b in Backend.objects.filter(drained=False, offline=False): |
81 | cc7c0f44 | Christos Stavrakakis | backend = {} |
82 | cc7c0f44 | Christos Stavrakakis | for a in attrs: |
83 | cc7c0f44 | Christos Stavrakakis | backend[a] = getattr(b, a)
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84 | cc7c0f44 | Christos Stavrakakis | backends[b.id] = backend |
85 | cc7c0f44 | Christos Stavrakakis | return backends
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86 | cc7c0f44 | Christos Stavrakakis | |
87 | cc7c0f44 | Christos Stavrakakis | |
88 | cc7c0f44 | Christos Stavrakakis | def flavor_disk(flavor): |
89 | cc7c0f44 | Christos Stavrakakis | """ Get flavor's 'real' disk size
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90 | cc7c0f44 | Christos Stavrakakis |
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91 | cc7c0f44 | Christos Stavrakakis | """
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92 | cc7c0f44 | Christos Stavrakakis | if flavor.disk_template == 'drbd': |
93 | cc7c0f44 | Christos Stavrakakis | return flavor.disk * 1024 * 2 |
94 | cc7c0f44 | Christos Stavrakakis | else:
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95 | cc7c0f44 | Christos Stavrakakis | return flavor.disk * 1024 |
96 | cc7c0f44 | Christos Stavrakakis | |
97 | cc7c0f44 | Christos Stavrakakis | |
98 | cc7c0f44 | Christos Stavrakakis | def reduce_backend_resources(backend, vm): |
99 | cc7c0f44 | Christos Stavrakakis | """ Conservatively update the resources of a backend.
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100 | cc7c0f44 | Christos Stavrakakis |
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101 | cc7c0f44 | Christos Stavrakakis | Reduce the free resources of the backend by the size of the of the vm that
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102 | cc7c0f44 | Christos Stavrakakis | will host. This is an underestimation of the backend capabilities.
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103 | cc7c0f44 | Christos Stavrakakis |
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104 | cc7c0f44 | Christos Stavrakakis | """
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105 | cc7c0f44 | Christos Stavrakakis | |
106 | cc7c0f44 | Christos Stavrakakis | new_mfree = backend.mfree - vm['ram']
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107 | cc7c0f44 | Christos Stavrakakis | new_dfree = backend.dfree - vm['disk']
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108 | cc7c0f44 | Christos Stavrakakis | backend.mfree = 0 if new_mfree < 0 else new_mfree |
109 | cc7c0f44 | Christos Stavrakakis | backend.dfree = 0 if new_dfree < 0 else new_dfree |
110 | cc7c0f44 | Christos Stavrakakis | backend.pinst_cnt += 1
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111 | cc7c0f44 | Christos Stavrakakis | |
112 | cc7c0f44 | Christos Stavrakakis | backend.save() |
113 | cc7c0f44 | Christos Stavrakakis | |
114 | cc7c0f44 | Christos Stavrakakis | |
115 | cc7c0f44 | Christos Stavrakakis | def refresh_backends_stats(): |
116 | cc7c0f44 | Christos Stavrakakis | """ Refresh the statistics of the backends.
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117 | cc7c0f44 | Christos Stavrakakis |
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118 | cc7c0f44 | Christos Stavrakakis | Set db backend state to the actual state of the backend, if
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119 | cc7c0f44 | Christos Stavrakakis | BACKEND_REFRESH_MIN time has passed.
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120 | cc7c0f44 | Christos Stavrakakis |
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121 | cc7c0f44 | Christos Stavrakakis | """
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122 | cc7c0f44 | Christos Stavrakakis | |
123 | cc7c0f44 | Christos Stavrakakis | now = datetime.datetime.now() |
124 | cc7c0f44 | Christos Stavrakakis | delta = datetime.timedelta(minutes=settings.BACKEND_REFRESH_MIN) |
125 | cc7c0f44 | Christos Stavrakakis | for b in Backend.objects.filter(drained=False, offline=False): |
126 | cc7c0f44 | Christos Stavrakakis | if now > b.updated + delta:
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127 | cc7c0f44 | Christos Stavrakakis | update_resources(b) |