Dev: Add a method of comparison

graphite_beacon/alerts.py

@@ -5,6 +5,7 @@
 from . import _compat as _
 from .graphite import GraphiteRecord
 from .utils import (
+    COMPARISON,
     HISTORICAL,
     LOGICAL_OPERATORS,
     convert_to_format,
@@ -13,6 +14,7 @@
     parse_rule,
 )
 import math
+import time
 from collections import deque, defaultdict
 from itertools import islice
 
@@ -80,6 +82,7 @@ def __init__(self, reactor, **options):
         self.waiting = False
         self.state = {None: "normal", "waiting": "normal", "loading": "normal"}
         self.history = defaultdict(lambda: sliceable_deque([], self.history_size))
+        self.comparing = {}
 
         LOGGER.info("Alert '%s': has inited", self)
 
@@ -205,6 +208,18 @@ def get_value_for_expr(self, expr, target):
                 return None
             rvalue = sum(history) / float(len(history))
 
+        if rvalue == COMPARISON:
+            current_time = int(time.time())
+            if self.comparing.has_key(target) and self.comparing[target]['time'] == current_time:
+                rvalue = self.comparing[target]['value']
+            else:
+                rvalue = self.get_graph_comparison()
+                if rvalue != -1:
+                    if not self.comparing.has_key(target):
+                        self.comparing[target] = {}
+                    self.comparing[target]['value'] = rvalue
+                    self.comparing[target]['time'] = current_time
+
         rvalue = expr['mod'](rvalue)
         return rvalue
 
@@ -226,6 +241,10 @@ def load(self):
         """Load from remote."""
         raise NotImplementedError()
 
+    def get_graph_comparison(self):
+        """Only from graphite."""
+        raise NotImplementedError()
+
 
 class GraphiteAlert(BaseAlert):
 
@@ -241,6 +260,7 @@ def configure(self, **options):
         self.default_nan_value = options.get(
             'default_nan_value', self.reactor.options['default_nan_value'])
         self.ignore_nan = options.get('ignore_nan', self.reactor.options['ignore_nan'])
+        self.compare_size = options.get('compare_size', self.reactor.options['compare_size'])
         assert self.method in METHODS, "Method is invalid"
 
         self.auth_username = self.reactor.options.get('auth_username')
@@ -274,6 +294,7 @@ def load(self):
                 self.check(data)
                 self.notify('normal', 'Metrics are loaded', target='loading', ntype='common')
             except Exception as e:
+                LOGGER.debug("ee: %s", str(e))
                 self.notify(
                     self.loading_error, 'Loading error: %s' % e, target='loading', ntype='common')
             self.waiting = False
@@ -293,6 +314,29 @@ def _graphite_url(self, query, raw_data=False, graphite_url=None):
             url = "{0}&rawData=true".format(url)
         return url
 
+    def get_graph_comparison(self):
+        time_shift = self.compare_size
+        if time_shift[0] != '-':
+            time_shift = '-' + time_shift
+
+        query = 'timeShift(' + self.query + ', "' + time_shift + '")'
+        url = self._graphite_url(
+            query, graphite_url=self.reactor.options.get('graphite_url'), raw_data=True)
+
+        http_client = hc.HTTPClient()
+        try:
+            response = http_client.fetch(url, auth_username=self.auth_username,
+                                         auth_password=self.auth_password,
+                                         request_timeout=self.request_timeout,
+                                         connect_timeout=self.connect_timeout)
+            record = GraphiteRecord(response.body.decode('utf-8'), self.default_nan_value, self.ignore_nan)
+            value = getattr(record, self.method)
+            LOGGER.debug("%s [%s]: %s", self.name, record.target, value)
+            return value
+        except Exception as e:
+            LOGGER.error('No data to compare: %s', str(e))
+            return -1
+
 
 class URLAlert(BaseAlert):
 

graphite_beacon/core.py

@@ -32,6 +32,7 @@ class Reactor(object):
         'debug': False,
         'format': 'short',
         'graphite_url': 'http://localhost',
+        'compare_size': '7d',
         'history_size': '1day',
         'interval': '10minute',
         'logging': 'info',

graphite_beacon/utils.py

@@ -43,6 +43,7 @@
 IDENTITY = lambda x: x
 
 
+COMPARISON = 'comparison'
 HISTORICAL = 'historical'
 COMPARATORS = {'>': op.gt, '>=': op.ge, '<': op.lt, '<=': op.le, '==': op.eq, '!=': op.ne}
 OPERATORS = {'*': op.mul, '/': op.truediv, '+': op.add, '-': op.sub}
@@ -51,6 +52,7 @@
 RULE_TOKENIZER = make_tokenizer(
     [
         (u'Level', (r'(critical|warning|normal)',)),
+        (u'Comparison', (COMPARISON,)),
         (u'Historical', (HISTORICAL,)),
         (u'Comparator', (r'({0})'.format('|'.join(sorted(COMPARATORS.keys(), reverse=True))),)),
         (u'LogicalOperator', (r'({0})'.format('|'.join(LOGICAL_OPERATORS.keys())),)),
@@ -113,12 +115,13 @@ def _parse_rule(seq):
     level = toktype(u'Level')
     comparator = toktype(u'Comparator') >> COMPARATORS.get
     number = toktype(u'Number') >> float
+    comparison = toktype(u'Comparison')
     historical = toktype(u'Historical')
     unit = toktype(u'Unit')
     operator = toktype(u'Operator')
     logical_operator = toktype(u'LogicalOperator') >> LOGICAL_OPERATORS.get
 
-    exp = comparator + ((number + maybe(unit)) | historical) + maybe(operator + number)
+    exp = comparator + ((number + maybe(unit)) | comparison | historical) + maybe(operator + number)
     rule = (
         level + s_sep(':') + exp + many(logical_operator + exp)
     )
@@ -130,7 +133,7 @@ def _parse_rule(seq):
 def _parse_expr(expr):
     cond, value, mod = expr
 
-    if value != HISTORICAL:
+    if value != HISTORICAL and value != COMPARISON:
         value = convert_from_format(*value)
 
     if mod: