summaryrefslogtreecommitdiffstats
path: root/python.d/go_expvar.chart.py
blob: cbd462570e497e664bef4f28a589a733827b5c8b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
# -*- coding: utf-8 -*-
# Description: go_expvar netdata python.d module
# Author: Jan Kral (kralewitz)

from __future__ import division
import json

from bases.FrameworkServices.UrlService import UrlService

# default module values (can be overridden per job in `config`)
# update_every = 2
priority = 60000
retries = 60


MEMSTATS_CHARTS = {
    'memstats_heap': {
        'options': ['heap', 'memory: size of heap memory structures', 'kB', 'memstats',
                    'expvar.memstats.heap', 'line'],
        'lines': [
            ['memstats_heap_alloc', 'alloc', 'absolute', 1, 1024],
            ['memstats_heap_inuse', 'inuse', 'absolute', 1, 1024]
        ]},
    'memstats_stack': {
        'options': ['stack', 'memory: size of stack memory structures', 'kB', 'memstats',
                    'expvar.memstats.stack', 'line'],
        'lines': [
            ['memstats_stack_inuse', 'inuse', 'absolute', 1, 1024]
        ]},
    'memstats_mspan': {
        'options': ['mspan', 'memory: size of mspan memory structures', 'kB', 'memstats',
                    'expvar.memstats.mspan', 'line'],
        'lines': [
            ['memstats_mspan_inuse', 'inuse', 'absolute', 1, 1024]
        ]},
    'memstats_mcache': {
        'options': ['mcache', 'memory: size of mcache memory structures', 'kB', 'memstats',
                    'expvar.memstats.mcache', 'line'],
        'lines': [
            ['memstats_mcache_inuse', 'inuse', 'absolute', 1, 1024]
        ]},
    'memstats_live_objects': {
        'options': ['live_objects', 'memory: number of live objects', 'objects', 'memstats',
                    'expvar.memstats.live_objects', 'line'],
        'lines': [
            ['memstats_live_objects', 'live']
        ]},
    'memstats_sys': {
        'options': ['sys', 'memory: size of reserved virtual address space', 'kB', 'memstats',
                    'expvar.memstats.sys', 'line'],
        'lines': [
            ['memstats_sys', 'sys', 'absolute', 1, 1024]
        ]},
    'memstats_gc_pauses': {
        'options': ['gc_pauses', 'memory: average duration of GC pauses', 'ns', 'memstats',
                    'expvar.memstats.gc_pauses', 'line'],
        'lines': [
            ['memstats_gc_pauses', 'avg']
        ]},
}

MEMSTATS_ORDER = ['memstats_heap', 'memstats_stack', 'memstats_mspan', 'memstats_mcache',
                  'memstats_sys', 'memstats_live_objects', 'memstats_gc_pauses']


def flatten(d, top='', sep='.'):
    items = []
    for key, val in d.items():
        nkey = top + sep + key if top else key
        if isinstance(val, dict):
            items.extend(flatten(val, nkey, sep=sep).items())
        else:
            items.append((nkey, val))
    return dict(items)


class Service(UrlService):
    def __init__(self, configuration=None, name=None):
        UrlService.__init__(self, configuration=configuration, name=name)

        # if memstats collection is enabled, add the charts and their order
        if self.configuration.get('collect_memstats'):
            self.definitions = dict(MEMSTATS_CHARTS)
            self.order = list(MEMSTATS_ORDER)
        else:
            self.definitions = dict()
            self.order = list()

        # if extra charts are defined, parse their config
        extra_charts = self.configuration.get('extra_charts')
        if extra_charts:
            self._parse_extra_charts_config(extra_charts)

    def check(self):
        """
        Check if the module can collect data:
        1) At least one JOB configuration has to be specified
        2) The JOB configuration needs to define the URL and either collect_memstats must be enabled or at least one
           extra_chart must be defined.

        The configuration and URL check is provided by the UrlService class.
        """

        if not (self.configuration.get('extra_charts') or self.configuration.get('collect_memstats')):
            self.error('Memstats collection is disabled and no extra_charts are defined, disabling module.')
            return False

        return UrlService.check(self)

    def _parse_extra_charts_config(self, extra_charts_config):

        # a place to store the expvar keys and their types
        self.expvars = dict()

        for chart in extra_charts_config:

            chart_dict = dict()
            chart_id = chart.get('id')
            chart_lines = chart.get('lines')
            chart_opts = chart.get('options', dict())

            if not all([chart_id, chart_lines]):
                self.info('Chart {0} has no ID or no lines defined, skipping'.format(chart))
                continue

            chart_dict['options'] = [
                chart_opts.get('name', ''),
                chart_opts.get('title', ''),
                chart_opts.get('units', ''),
                chart_opts.get('family', ''),
                chart_opts.get('context', ''),
                chart_opts.get('chart_type', 'line')
            ]
            chart_dict['lines'] = list()

            # add the lines to the chart
            for line in chart_lines:

                ev_key = line.get('expvar_key')
                ev_type = line.get('expvar_type')
                line_id = line.get('id')

                if not all([ev_key, ev_type, line_id]):
                    self.info('Line missing expvar_key, expvar_type, or line_id, skipping: {0}'.format(line))
                    continue

                if ev_type not in ['int', 'float']:
                    self.info('Unsupported expvar_type "{0}". Must be "int" or "float"'.format(ev_type))
                    continue

                if ev_key in self.expvars:
                    self.info('Duplicate expvar key {0}: skipping line.'.format(ev_key))
                    continue

                self.expvars[ev_key] = (ev_type, line_id)

                chart_dict['lines'].append(
                    [
                        line.get('id', ''),
                        line.get('name', ''),
                        line.get('algorithm', ''),
                        line.get('multiplier', 1),
                        line.get('divisor', 100 if ev_type == 'float' else 1),
                        line.get('hidden', False)
                    ]
                )

            self.order.append(chart_id)
            self.definitions[chart_id] = chart_dict

    def _get_data(self):
        """
        Format data received from http request
        :return: dict
        """

        raw_data = self._get_raw_data()
        if not raw_data:
            return None

        data = json.loads(raw_data)

        expvars = dict()
        if self.configuration.get('collect_memstats'):
            expvars.update(self._parse_memstats(data))

        if self.configuration.get('extra_charts'):
            # the memstats part of the data has been already parsed, so we remove it before flattening and checking
            #   the rest of the data, thus avoiding needless iterating over the multiply nested memstats dict.
            del (data['memstats'])
            flattened = flatten(data)
            for k, v in flattened.items():
                ev = self.expvars.get(k)
                if not ev:
                    # expvar is not defined in config, skip it
                    continue
                try:
                    key_type, line_id = ev
                    if key_type == 'int':
                        expvars[line_id] = int(v)
                    elif key_type == 'float':
                        # if the value type is float, multiply it by 1000 and set line divisor to 1000
                        expvars[line_id] = float(v) * 100
                except ValueError:
                    self.info('Failed to parse value for key {0} as {1}, ignoring key.'.format(k, key_type))
                    del self.expvars[k]

        return expvars

    @staticmethod
    def _parse_memstats(data):

        memstats = data['memstats']

        # calculate the number of live objects in memory
        live_objs = int(memstats['Mallocs']) - int(memstats['Frees'])

        # calculate GC pause times average
        # the Go runtime keeps the last 256 GC pause durations in a circular buffer,
        #  so we need to filter out the 0 values before the buffer is filled
        gc_pauses = memstats['PauseNs']
        try:
            gc_pause_avg = sum(gc_pauses) / len([x for x in gc_pauses if x > 0])
        # no GC cycles have occured yet
        except ZeroDivisionError:
            gc_pause_avg = 0

        return {
            'memstats_heap_alloc': memstats['HeapAlloc'],
            'memstats_heap_inuse': memstats['HeapInuse'],
            'memstats_stack_inuse': memstats['StackInuse'],
            'memstats_mspan_inuse': memstats['MSpanInuse'],
            'memstats_mcache_inuse': memstats['MCacheInuse'],
            'memstats_sys': memstats['Sys'],
            'memstats_live_objects': live_objs,
            'memstats_gc_pauses': gc_pause_avg,
        }