1 | # -*- coding: utf-8 -*- |
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2 | # |
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3 | # This file is part of Glances. |
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4 | # |
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5 | # Copyright (C) 2019 Nicolargo <[email protected]> |
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6 | # |
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7 | # Glances is free software; you can redistribute it and/or modify |
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8 | # it under the terms of the GNU Lesser General Public License as published by |
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9 | # the Free Software Foundation, either version 3 of the License, or |
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10 | # (at your option) any later version. |
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11 | # |
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12 | # Glances is distributed in the hope that it will be useful, |
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13 | # but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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15 | # GNU Lesser General Public License for more details. |
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16 | # |
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17 | # You should have received a copy of the GNU Lesser General Public License |
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18 | # along with this program. If not, see <http://www.gnu.org/licenses/>. |
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19 | |||
20 | """Cassandra/Scylla interface class.""" |
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21 | |||
22 | import sys |
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23 | from datetime import datetime |
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24 | from numbers import Number |
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25 | |||
26 | from glances.logger import logger |
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27 | from glances.exports.glances_export import GlancesExport |
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28 | from glances.compat import iteritems |
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29 | |||
30 | from cassandra.auth import PlainTextAuthProvider |
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31 | from cassandra.cluster import Cluster |
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32 | from cassandra.util import uuid_from_time |
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33 | from cassandra import InvalidRequest |
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34 | |||
35 | |||
36 | class Export(GlancesExport): |
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37 | |||
38 | """This class manages the Cassandra/Scylla export module.""" |
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39 | |||
40 | def __init__(self, config=None, args=None): |
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41 | """Init the Cassandra export IF.""" |
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42 | super(Export, self).__init__(config=config, args=args) |
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43 | |||
44 | # Mandatories configuration keys (additional to host and port) |
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45 | self.keyspace = None |
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46 | |||
47 | # Optionals configuration keys |
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48 | self.protocol_version = 3 |
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49 | self.replication_factor = 2 |
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50 | self.table = None |
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51 | self.username = None |
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52 | self.password = None |
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53 | |||
54 | # Load the Cassandra configuration file section |
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55 | self.export_enable = self.load_conf('cassandra', |
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56 | mandatories=['host', 'port', 'keyspace'], |
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57 | options=['protocol_version', |
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58 | 'replication_factor', |
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59 | 'table', |
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60 | 'username', |
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61 | 'password']) |
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62 | if not self.export_enable: |
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63 | sys.exit(2) |
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64 | |||
65 | # Init the Cassandra client |
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66 | self.cluster, self.session = self.init() |
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67 | |||
68 | def init(self): |
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69 | """Init the connection to the Cassandra server.""" |
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70 | if not self.export_enable: |
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71 | return None |
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72 | |||
73 | # if username and/or password are not set the connection will try to connect with no auth |
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74 | auth_provider = PlainTextAuthProvider( |
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75 | username=self.username, password=self.password) |
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76 | |||
77 | # Cluster |
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78 | try: |
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79 | cluster = Cluster([self.host], |
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80 | port=int(self.port), |
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81 | protocol_version=int(self.protocol_version), |
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82 | auth_provider=auth_provider) |
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83 | session = cluster.connect() |
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84 | except Exception as e: |
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0 ignored issues
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The name
e does not conform to the variable naming conventions ((([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$ ).
This check looks for invalid names for a range of different identifiers. You can set regular expressions to which the identifiers must conform if the defaults do not match your requirements. If your project includes a Pylint configuration file, the settings contained in that file take precedence. To find out more about Pylint, please refer to their site.
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85 | logger.critical("Cannot connect to Cassandra cluster '%s:%s' (%s)" % (self.host, self.port, e)) |
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86 | sys.exit(2) |
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87 | |||
88 | # Keyspace |
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89 | try: |
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90 | session.set_keyspace(self.keyspace) |
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91 | except InvalidRequest as e: |
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0 ignored issues
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The name
e does not conform to the variable naming conventions ((([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$ ).
This check looks for invalid names for a range of different identifiers. You can set regular expressions to which the identifiers must conform if the defaults do not match your requirements. If your project includes a Pylint configuration file, the settings contained in that file take precedence. To find out more about Pylint, please refer to their site.
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92 | logger.info("Create keyspace {} on the Cassandra cluster".format(self.keyspace)) |
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93 | c = "CREATE KEYSPACE %s WITH replication = { 'class': 'SimpleStrategy', 'replication_factor': '%s' }" % (self.keyspace, self.replication_factor) |
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0 ignored issues
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The name
c does not conform to the variable naming conventions ((([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$ ).
This check looks for invalid names for a range of different identifiers. You can set regular expressions to which the identifiers must conform if the defaults do not match your requirements. If your project includes a Pylint configuration file, the settings contained in that file take precedence. To find out more about Pylint, please refer to their site.
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94 | session.execute(c) |
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95 | session.set_keyspace(self.keyspace) |
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96 | |||
97 | logger.info( |
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98 | "Stats will be exported to Cassandra cluster {} ({}) in keyspace {}".format( |
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99 | cluster.metadata.cluster_name, cluster.metadata.all_hosts(), self.keyspace)) |
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100 | |||
101 | # Table |
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102 | try: |
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103 | session.execute("CREATE TABLE %s (plugin text, time timeuuid, stat map<text,float>, PRIMARY KEY (plugin, time)) WITH CLUSTERING ORDER BY (time DESC)" % self.table) |
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104 | except Exception: |
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0 ignored issues
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show
Catching very general exceptions such as
Exception is usually not recommended.
Generally, you would want to handle very specific errors in the exception handler. This ensure that you do not hide other types of errors which should be fixed. So, unless you specifically plan to handle any error, consider adding a more specific exception.
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105 | logger.debug("Cassandra table %s already exist" % self.table) |
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106 | |||
107 | return cluster, session |
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108 | |||
109 | def export(self, name, columns, points): |
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110 | """Write the points to the Cassandra cluster.""" |
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111 | logger.debug("Export {} stats to Cassandra".format(name)) |
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112 | |||
113 | # Remove non number stats and convert all to float (for Boolean) |
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114 | data = {k: float(v) for (k, v) in dict(zip(columns, points)).iteritems() if isinstance(v, Number)} |
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115 | |||
116 | # Write input to the Cassandra table |
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117 | try: |
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118 | |||
119 | stmt = "INSERT INTO {} (plugin, time, stat) VALUES (?, ?, ?)".format(self.table) |
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120 | query = self.session.prepare(stmt) |
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121 | self.session.execute( |
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122 | query, |
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123 | (name, uuid_from_time(datetime.now()), data) |
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124 | ) |
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125 | except Exception as e: |
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0 ignored issues
–
show
Catching very general exceptions such as
Exception is usually not recommended.
Generally, you would want to handle very specific errors in the exception handler. This ensure that you do not hide other types of errors which should be fixed. So, unless you specifically plan to handle any error, consider adding a more specific exception.
Loading history...
The name
e does not conform to the variable naming conventions ((([a-z][a-z0-9_]{2,30})|(_[a-z0-9_]*))$ ).
This check looks for invalid names for a range of different identifiers. You can set regular expressions to which the identifiers must conform if the defaults do not match your requirements. If your project includes a Pylint configuration file, the settings contained in that file take precedence. To find out more about Pylint, please refer to their site.
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126 | logger.error("Cannot export {} stats to Cassandra ({})".format(name, e)) |
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127 | |||
128 | def exit(self): |
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129 | """Close the Cassandra export module.""" |
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130 | # To ensure all connections are properly closed |
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131 | self.session.shutdown() |
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132 | self.cluster.shutdown() |
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133 | # Call the father method |
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134 | super(Export, self).exit() |
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135 |
Generally, you would want to handle very specific errors in the exception handler. This ensure that you do not hide other types of errors which should be fixed.
So, unless you specifically plan to handle any error, consider adding a more specific exception.