root / snf-cyclades-app / synnefo / logic / backend_allocator.py @ 23f29f98
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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 | 47d1d754 | Christos Stavrakakis | import logging |
31 | cc7c0f44 | Christos Stavrakakis | import datetime |
32 | cc7c0f44 | Christos Stavrakakis | from django.utils import importlib |
33 | cc7c0f44 | Christos Stavrakakis | |
34 | 710b1c43 | Christos Stavrakakis | from django.conf import settings |
35 | cc7c0f44 | Christos Stavrakakis | from synnefo.db.models import Backend |
36 | 710b1c43 | Christos Stavrakakis | from synnefo.logic import backend as backend_mod |
37 | cc7c0f44 | Christos Stavrakakis | |
38 | 47d1d754 | Christos Stavrakakis | log = logging.getLogger(__name__) |
39 | 47d1d754 | Christos Stavrakakis | |
40 | cc7c0f44 | Christos Stavrakakis | |
41 | cc7c0f44 | Christos Stavrakakis | class BackendAllocator(): |
42 | cc7c0f44 | Christos Stavrakakis | """Wrapper class for instance allocation.
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43 | cc7c0f44 | Christos Stavrakakis |
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44 | cc7c0f44 | Christos Stavrakakis | """
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45 | cc7c0f44 | Christos Stavrakakis | def __init__(self): |
46 | cc7c0f44 | Christos Stavrakakis | self.strategy_mod =\
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47 | 710b1c43 | Christos Stavrakakis | importlib.import_module(settings.BACKEND_ALLOCATOR_MODULE) |
48 | cc7c0f44 | Christos Stavrakakis | |
49 | 5dd9d123 | Christos Stavrakakis | def allocate(self, userid, flavor): |
50 | adc46059 | Christos Stavrakakis | """Allocate a vm of the specified flavor to a backend.
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51 | adc46059 | Christos Stavrakakis |
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52 | adc46059 | Christos Stavrakakis | Warning!!: An explicit commit is required after calling this function,
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53 | adc46059 | Christos Stavrakakis | in order to release the locks acquired by the get_available_backends
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54 | adc46059 | Christos Stavrakakis | function.
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55 | adc46059 | Christos Stavrakakis |
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56 | adc46059 | Christos Stavrakakis | """
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57 | 5dd9d123 | Christos Stavrakakis | |
58 | 5dd9d123 | Christos Stavrakakis | backend = None
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59 | 5dd9d123 | Christos Stavrakakis | backend = get_backend_for_user(userid) |
60 | 5dd9d123 | Christos Stavrakakis | if backend:
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61 | 5dd9d123 | Christos Stavrakakis | return backend
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62 | 5dd9d123 | Christos Stavrakakis | |
63 | cc7c0f44 | Christos Stavrakakis | # Get the size of the vm
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64 | cc7c0f44 | Christos Stavrakakis | disk = flavor_disk(flavor) |
65 | cc7c0f44 | Christos Stavrakakis | ram = flavor.ram |
66 | cc7c0f44 | Christos Stavrakakis | cpu = flavor.cpu |
67 | cc7c0f44 | Christos Stavrakakis | vm = {'ram': ram, 'disk': disk, 'cpu': cpu} |
68 | cc7c0f44 | Christos Stavrakakis | |
69 | 47d1d754 | Christos Stavrakakis | log.debug("Allocating VM: %r", vm)
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70 | 47d1d754 | Christos Stavrakakis | |
71 | cc7c0f44 | Christos Stavrakakis | # Get available backends
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72 | f15bf3d9 | Christos Stavrakakis | available_backends = get_available_backends(flavor) |
73 | cc7c0f44 | Christos Stavrakakis | |
74 | cc7c0f44 | Christos Stavrakakis | if not available_backends: |
75 | cc7c0f44 | Christos Stavrakakis | return None |
76 | cc7c0f44 | Christos Stavrakakis | |
77 | cc7c0f44 | Christos Stavrakakis | # Find the best backend to host the vm, based on the allocation
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78 | cc7c0f44 | Christos Stavrakakis | # strategy
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79 | 7fede91e | Christos Stavrakakis | backend = self.strategy_mod.allocate(available_backends, vm)
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80 | cc7c0f44 | Christos Stavrakakis | |
81 | 47d1d754 | Christos Stavrakakis | log.info("Allocated VM %r, in backend %s", vm, backend)
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82 | 47d1d754 | Christos Stavrakakis | |
83 | cc7c0f44 | Christos Stavrakakis | # Reduce the free resources of the selected backend by the size of
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84 | cc7c0f44 | Christos Stavrakakis | # the vm
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85 | cc7c0f44 | Christos Stavrakakis | reduce_backend_resources(backend, vm) |
86 | cc7c0f44 | Christos Stavrakakis | |
87 | cc7c0f44 | Christos Stavrakakis | return backend
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88 | cc7c0f44 | Christos Stavrakakis | |
89 | cc7c0f44 | Christos Stavrakakis | |
90 | f15bf3d9 | Christos Stavrakakis | def get_available_backends(flavor): |
91 | f15bf3d9 | Christos Stavrakakis | """Get the list of available backends that can host a new VM of a flavor.
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92 | f15bf3d9 | Christos Stavrakakis |
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93 | f15bf3d9 | Christos Stavrakakis | The list contains the backends that are online and that have enabled
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94 | f15bf3d9 | Christos Stavrakakis | the disk_template of the new VM.
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95 | f15bf3d9 | Christos Stavrakakis |
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96 | f15bf3d9 | Christos Stavrakakis | Also, if the new VM will be automatically connected to a public network,
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97 | f15bf3d9 | Christos Stavrakakis | the backends that do not have an available public IPv4 address are
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98 | f15bf3d9 | Christos Stavrakakis | excluded.
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99 | cc7c0f44 | Christos Stavrakakis |
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100 | cc7c0f44 | Christos Stavrakakis | """
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101 | 5d1f6b84 | Christos Stavrakakis | disk_template = flavor.disk_template |
102 | 5d1f6b84 | Christos Stavrakakis | # Ganeti knows only the 'ext' disk template, but the flavors disk template
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103 | 5d1f6b84 | Christos Stavrakakis | # includes the provider.
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104 | 5d1f6b84 | Christos Stavrakakis | if disk_template.startswith("ext_"): |
105 | 5d1f6b84 | Christos Stavrakakis | disk_template = "ext"
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106 | 5d1f6b84 | Christos Stavrakakis | |
107 | 996ddb98 | Christos Stavrakakis | backends = Backend.objects.select_for_update().filter(offline=False,
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108 | 996ddb98 | Christos Stavrakakis | drained=False)
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109 | c9e99213 | Christos Stavrakakis | # Update the disk_templates if there are empty.
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110 | c9e99213 | Christos Stavrakakis | [backend_mod.update_backend_disk_templates(b) |
111 | c9e99213 | Christos Stavrakakis | for b in backends if not b.disk_templates] |
112 | 996ddb98 | Christos Stavrakakis | backends = filter(lambda b: disk_template in b.disk_templates, |
113 | 996ddb98 | Christos Stavrakakis | list(backends))
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114 | c9e99213 | Christos Stavrakakis | |
115 | c9e99213 | Christos Stavrakakis | # Update the backend stats if it is needed
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116 | c9e99213 | Christos Stavrakakis | refresh_backends_stats(backends) |
117 | c9e99213 | Christos Stavrakakis | |
118 | 8f2aa316 | Christos Stavrakakis | return backends
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119 | f96f60fd | Christos Stavrakakis | |
120 | f96f60fd | Christos Stavrakakis | |
121 | cc7c0f44 | Christos Stavrakakis | def flavor_disk(flavor): |
122 | cc7c0f44 | Christos Stavrakakis | """ Get flavor's 'real' disk size
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123 | cc7c0f44 | Christos Stavrakakis |
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124 | cc7c0f44 | Christos Stavrakakis | """
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125 | cc7c0f44 | Christos Stavrakakis | if flavor.disk_template == 'drbd': |
126 | cc7c0f44 | Christos Stavrakakis | return flavor.disk * 1024 * 2 |
127 | cc7c0f44 | Christos Stavrakakis | else:
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128 | cc7c0f44 | Christos Stavrakakis | return flavor.disk * 1024 |
129 | cc7c0f44 | Christos Stavrakakis | |
130 | cc7c0f44 | Christos Stavrakakis | |
131 | cc7c0f44 | Christos Stavrakakis | def reduce_backend_resources(backend, vm): |
132 | cc7c0f44 | Christos Stavrakakis | """ Conservatively update the resources of a backend.
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133 | cc7c0f44 | Christos Stavrakakis |
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134 | cc7c0f44 | Christos Stavrakakis | Reduce the free resources of the backend by the size of the of the vm that
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135 | cc7c0f44 | Christos Stavrakakis | will host. This is an underestimation of the backend capabilities.
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136 | cc7c0f44 | Christos Stavrakakis |
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137 | cc7c0f44 | Christos Stavrakakis | """
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138 | cc7c0f44 | Christos Stavrakakis | |
139 | cc7c0f44 | Christos Stavrakakis | new_mfree = backend.mfree - vm['ram']
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140 | cc7c0f44 | Christos Stavrakakis | new_dfree = backend.dfree - vm['disk']
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141 | cc7c0f44 | Christos Stavrakakis | backend.mfree = 0 if new_mfree < 0 else new_mfree |
142 | cc7c0f44 | Christos Stavrakakis | backend.dfree = 0 if new_dfree < 0 else new_dfree |
143 | cc7c0f44 | Christos Stavrakakis | backend.pinst_cnt += 1
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144 | cc7c0f44 | Christos Stavrakakis | |
145 | cc7c0f44 | Christos Stavrakakis | backend.save() |
146 | cc7c0f44 | Christos Stavrakakis | |
147 | cc7c0f44 | Christos Stavrakakis | |
148 | 9cf4a3c0 | Christos Stavrakakis | def refresh_backends_stats(backends): |
149 | cc7c0f44 | Christos Stavrakakis | """ Refresh the statistics of the backends.
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150 | cc7c0f44 | Christos Stavrakakis |
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151 | cc7c0f44 | Christos Stavrakakis | Set db backend state to the actual state of the backend, if
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152 | cc7c0f44 | Christos Stavrakakis | BACKEND_REFRESH_MIN time has passed.
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153 | cc7c0f44 | Christos Stavrakakis |
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154 | cc7c0f44 | Christos Stavrakakis | """
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155 | cc7c0f44 | Christos Stavrakakis | |
156 | cc7c0f44 | Christos Stavrakakis | now = datetime.datetime.now() |
157 | 710b1c43 | Christos Stavrakakis | delta = datetime.timedelta(minutes=settings.BACKEND_REFRESH_MIN) |
158 | 9cf4a3c0 | Christos Stavrakakis | for b in backends: |
159 | cc7c0f44 | Christos Stavrakakis | if now > b.updated + delta:
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160 | 9cf4a3c0 | Christos Stavrakakis | log.debug("Updating resources of backend %r. Last Updated %r",
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161 | 9cf4a3c0 | Christos Stavrakakis | b, b.updated) |
162 | 710b1c43 | Christos Stavrakakis | backend_mod.update_backend_resources(b) |
163 | 5dd9d123 | Christos Stavrakakis | |
164 | 5dd9d123 | Christos Stavrakakis | |
165 | 5dd9d123 | Christos Stavrakakis | def get_backend_for_user(userid): |
166 | 5dd9d123 | Christos Stavrakakis | """Find fixed Backend for user based on BACKEND_PER_USER setting."""
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167 | 5dd9d123 | Christos Stavrakakis | |
168 | 710b1c43 | Christos Stavrakakis | backend = settings.BACKEND_PER_USER.get(userid) |
169 | 5dd9d123 | Christos Stavrakakis | |
170 | 5dd9d123 | Christos Stavrakakis | if not backend: |
171 | 5dd9d123 | Christos Stavrakakis | return None |
172 | 5dd9d123 | Christos Stavrakakis | |
173 | 5dd9d123 | Christos Stavrakakis | try:
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174 | 5dd9d123 | Christos Stavrakakis | try:
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175 | 5dd9d123 | Christos Stavrakakis | backend_id = int(backend)
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176 | 5dd9d123 | Christos Stavrakakis | return Backend.objects.get(id=backend_id)
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177 | 5dd9d123 | Christos Stavrakakis | except ValueError: |
178 | 5dd9d123 | Christos Stavrakakis | pass
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179 | 5dd9d123 | Christos Stavrakakis | |
180 | 5dd9d123 | Christos Stavrakakis | backend_name = str(backend)
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181 | 5dd9d123 | Christos Stavrakakis | return Backend.objects.get(clustername=backend_name)
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182 | 5dd9d123 | Christos Stavrakakis | except Backend.DoesNotExist:
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183 | 5dd9d123 | Christos Stavrakakis | log.error("Invalid backend %s for user %s", backend, userid) |