Memcache.poll() - Code Metrics - s4z/plumd - Measure and Improve Code Quality continuously with Scrutinizer

Memcache.poll() B
last analyzed 2017-05-25 01:53 UTC

↳ Parent: Memcache

Complexity

Conditions

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Importance

Changes	2
Bugs	1	Features	1

Metric	Value
c	2
b	1
f	1
dl	0
loc	25
rs	8.0894
cc	5

# -*- coding: utf-8 -*-
"""Memcache metrics."""
import sys
import time
import socket
import os.path

import plumd
from plumd.util import Differential

PY3 = sys.version_info > (3,)


__author__ = 'Kenny Freeman'
__email__ = '[email protected]'
__license__ = "ISCL"
__docformat__ = 'reStructuredText'


class Memcache(plumd.Reader):
    """Plugin to record memcache stats."""

    STAT_CMD = "stats\n"
    RECV_SIZE = 4096

    # default config values
    defaults = {
        'poll.interval': 10,
        'gauges': [
            "auth_cmds",
            "auth_errors",
            "bytes",
            "bytes_read",
            "bytes_written",
            "cas_badval",
            "cas_hits",
            "cas_misses",
            "cmd_flush",
            "cmd_get",
            "cmd_set",
            "cmd_touch",
            "connection_structures",
            "conn_yields",
            "curr_connections",
            "curr_items",
            "decr_hits",
            "decr_misses",
            "delete_hits",
            "delete_misses",
            "evicted_unfetched",
            "evictions",
            "expired_unfetched",
            "get_hits",
            "get_misses",
            "hash_bytes",
            "hash_is_expanding",
            "hash_power_level",
            "incr_hits",
            "incr_misses",
            "limit_maxbytes",
            "listen_disabled_num",
            "reclaimed",
            "reserved_fds",
            "rusage_system",
            "rusage_user",
            "threads",
            "total_connections",
            "total_items",
            "touch_hits",
            "touch_misses",
            "uptime"
        ],
        'rates': [],
        'host': '127.0.0.1',  # memcache server hostname/ip
        'port': 11211,       # memcache server port
        'socket': None,      # use tcp or unix domain socket
        'timeout': 10        # connection timeouts
    }

    def __init__(self, log, config):
        """Plugin to record memcache stats.

        :param log: A logger
        :type log: logging.RootLogger
        :param config: a plumd.config.Conf configuration helper instance.
        :type config: plumd.config.Conf
        """
        super(Memcache, self).__init__(log, config)
        self.config.defaults(Memcache.defaults)

        # metrics to record
        self.gauges = self.config.get('gauges')
        self.rates = self.config.get('rates')

        # memcached connection - either unix socket or tcp
        spath = self.config.get('socket')
        if spath is None or not os.path.exists(spath):
            host = self.config.get('host')
            port = self.config.get('port')
            self.addr = (host, port)
            self.sfamily = socket.AF_INET
        else:
            self.addr = spath
            self.sfamily = socket.AF_UNIX

        self.socket = None
        self.timeout = config.get('timeout')
        self.calc = Differential()

    def poll(self):
        """Query memcache for stats.

        :rtype: ResultSet
        """
        result = plumd.Result("memcache")

        name = self.name
        stats = self.get_stats()
        times = time.time()

        # record gauges
        for stat in self.gauges:
            if stat in stats:
                mname = "{0}.{1}".format(name, stat)
                result.add(plumd.Float(mname, stats[stat]))

        # record rates
        for stat in self.rates:
            if stat in stats:
                mname = "{0}.{1}".format(name, stat)
                mval = self.calc.per_second(mname, float(stats[stat]), times)
                result.add(plumd.Float(mname, mval))

        return plumd.ResultSet([result])

    def get_stats(self):
        """Request and read stats from memcache socket."""
        stats = {}

        if not self.socket and not self.connect():
            return {}

        try:
            if PY3:
                self.socket.sendall(bytes(Memcache.STAT_CMD, 'utf8'))
            else:
                self.socket.sendall(Memcache.STAT_CMD)

            st_str = self.socket.recv(Memcache.RECV_SIZE)

            for line in st_str.split("\n"):
                vals = line.split()
                if len(vals) != 3:
                    continue
                stype, sname, sval = vals
                if stype == "STAT":
                    msg = "Memcached: {0} = {1}"
                    stats[sname] = sval

        except Exception as exc:

            msg = "Memcached: {0}: poll: exception: {1}"
            self.log.error(msg.format(self.addr, exc))
            self.disconnect()

        return stats

    def connect(self):
        """Connect to memcached, returns True if sucessful, False otherwise.

        :rtype: bool
        """
        self.log.debug("Memcached: connecting: {0}".format(self.addr))
        if self.socket:
            self.disconnect()
        try:
            # create the socket
            self.socket = socket.socket(self.sfamily,
                                        socket.SOCK_STREAM)
            # set timeout for socket operations
            self.socket.settimeout(self.timeout)
            # connect
            self.socket.connect(self.addr)
            # log and return
            msg = "Memcached: connected: {0}"
            self.log.info(msg.format(self.addr))
            return True
        except Exception as exc:

            # log exception, ensure cleanup is done (disconnect)
            msg = "Memcached: {0}: connect: excception: {1}"
            self.log.error(msg.format(self.addr, exc))
            return False
        return False

    def disconnect(self):
        """Severe the memcached connection."""
        if self.socket:
            try:
                self.socket.close()
                self.socket = None
            except Exception as exc:

                msg = "Memcached: dicsonnect: exception {0}".format(exc)
                self.log.error(msg)
                self.socket = None


1			# -- coding: utf-8 --
2			"""Memcache metrics."""
3			import sys
4			import time
5			import socket
6			import os.path
7
8			import plumd
9			from plumd.util import Differential
10
11			PY3 = sys.version_info > (3,)
12
13
14			__author__ = 'Kenny Freeman'
15			__email__ = '[email protected]'
16			__license__ = "ISCL"
17			__docformat__ = 'reStructuredText'
18
19
20			class Memcache(plumd.Reader):
21			"""Plugin to record memcache stats."""
22
23			STAT_CMD = "stats\n"
24			RECV_SIZE = 4096
25
26			# default config values
27			defaults = {
28			'poll.interval': 10,
29			'gauges': [
30			"auth_cmds",
31			"auth_errors",
32			"bytes",
33			"bytes_read",
34			"bytes_written",
35			"cas_badval",
36			"cas_hits",
37			"cas_misses",
38			"cmd_flush",
39			"cmd_get",
40			"cmd_set",
41			"cmd_touch",
42			"connection_structures",
43			"conn_yields",
44			"curr_connections",
45			"curr_items",
46			"decr_hits",
47			"decr_misses",
48			"delete_hits",
49			"delete_misses",
50			"evicted_unfetched",
51			"evictions",
52			"expired_unfetched",
53			"get_hits",
54			"get_misses",
55			"hash_bytes",
56			"hash_is_expanding",
57			"hash_power_level",
58			"incr_hits",
59			"incr_misses",
60			"limit_maxbytes",
61			"listen_disabled_num",
62			"reclaimed",
63			"reserved_fds",
64			"rusage_system",
65			"rusage_user",
66			"threads",
67			"total_connections",
68			"total_items",
69			"touch_hits",
70			"touch_misses",
71			"uptime"
72			],
73			'rates': [],
74			'host': '127.0.0.1', # memcache server hostname/ip
75			'port': 11211, # memcache server port
76			'socket': None, # use tcp or unix domain socket
77			'timeout': 10 # connection timeouts
78			}
79
80			def __init__(self, log, config):
81			"""Plugin to record memcache stats.
82
83			:param log: A logger
84			:type log: logging.RootLogger
85			:param config: a plumd.config.Conf configuration helper instance.
86			:type config: plumd.config.Conf
87			"""
88			super(Memcache, self).__init__(log, config)
89			self.config.defaults(Memcache.defaults)
90
91			# metrics to record
92			self.gauges = self.config.get('gauges')
93			self.rates = self.config.get('rates')
94
95			# memcached connection - either unix socket or tcp
96			spath = self.config.get('socket')
97			if spath is None or not os.path.exists(spath):
98			host = self.config.get('host')
99			port = self.config.get('port')
100			self.addr = (host, port)
101			self.sfamily = socket.AF_INET
102			else:
103			self.addr = spath
104			self.sfamily = socket.AF_UNIX
105
106			self.socket = None
107			self.timeout = config.get('timeout')
108			self.calc = Differential()
109
110			def poll(self):
111			"""Query memcache for stats.
112
113			:rtype: ResultSet
114			"""
115			result = plumd.Result("memcache")
116
117			name = self.name
118			stats = self.get_stats()
119			times = time.time()
120
121			# record gauges
122			for stat in self.gauges:
123			if stat in stats:
124			mname = "{0}.{1}".format(name, stat)
125			result.add(plumd.Float(mname, stats[stat]))
126
127			# record rates
128			for stat in self.rates:
129			if stat in stats:
130			mname = "{0}.{1}".format(name, stat)
131			mval = self.calc.per_second(mname, float(stats[stat]), times)
132			result.add(plumd.Float(mname, mval))
133
134			return plumd.ResultSet([result])
135
136			def get_stats(self):
137			"""Request and read stats from memcache socket."""
138			stats = {}
139
140			if not self.socket and not self.connect():
141			return {}
142
143			try:
144			if PY3:
145			self.socket.sendall(bytes(Memcache.STAT_CMD, 'utf8'))
146			else:
147			self.socket.sendall(Memcache.STAT_CMD)
148
149			st_str = self.socket.recv(Memcache.RECV_SIZE)
150
151			for line in st_str.split("\n"):
152			vals = line.split()
153			if len(vals) != 3:
154			continue
155			stype, sname, sval = vals
156			if stype == "STAT":
157			msg = "Memcached: {0} = {1}"
158			stats[sname] = sval
159
160			except Exception as exc:
			0 ignored issues – show Best Practice introduced 2016-09-10 09:25 UTC by Report Bug Copy Issue Report 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...
161			msg = "Memcached: {0}: poll: exception: {1}"
162			self.log.error(msg.format(self.addr, exc))
163			self.disconnect()
164
165			return stats
166
167			def connect(self):
168			"""Connect to memcached, returns True if sucessful, False otherwise.
169
170			:rtype: bool
171			"""
172			self.log.debug("Memcached: connecting: {0}".format(self.addr))
173			if self.socket:
174			self.disconnect()
175			try:
176			# create the socket
177			self.socket = socket.socket(self.sfamily,
178			socket.SOCK_STREAM)
179			# set timeout for socket operations
180			self.socket.settimeout(self.timeout)
181			# connect
182			self.socket.connect(self.addr)
183			# log and return
184			msg = "Memcached: connected: {0}"
185			self.log.info(msg.format(self.addr))
186			return True
187			except Exception as exc:
			0 ignored issues – show Best Practice introduced 2016-11-13 07:47 UTC by Report Bug Copy Issue Report 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...
188			# log exception, ensure cleanup is done (disconnect)
189			msg = "Memcached: {0}: connect: excception: {1}"
190			self.log.error(msg.format(self.addr, exc))
191			return False
192			return False
193
194			def disconnect(self):
195			"""Severe the memcached connection."""
196			if self.socket:
197			try:
198			self.socket.close()
199			self.socket = None
200			except Exception as exc:
			0 ignored issues – show Best Practice introduced 2016-09-10 09:25 UTC by Report Bug Copy Issue Report 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...
201			msg = "Memcached: dicsonnect: exception {0}".format(exc)
202			self.log.error(msg)
203			self.socket = None
204

s4z / plumd

Memcache.poll() B last analyzed 2017-05-25 01:53 UTC

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Memcache.poll() B
last analyzed 2017-05-25 01:53 UTC