Merge branch 'release/2.1.0'

sebdah · Sep 30, 2015 · c20e724 · c20e724
2 parents 3fca1c5 + 300f319
commit c20e724
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diff --git a/.ropeproject/globalnames b/.ropeproject/globalnames
diff --git a/docs/configuration_options.rst b/docs/configuration_options.rst
@@ -41,8 +41,6 @@ Table configuration
 
 Important note: The table name is treated as a regular expression. That means that ``my_table`` also will match ``my_table2``, unless you express it as a valid regular expression; ``^my_table$``. This feature enables you to easily configure many tables or tables with dynamic names.
 
-Please note also that DynamoDB writes CloudWatch data every 5 minutes, thus ``reads/writes-upper/lower-threshold`` and ``throttled-reads/writes-upper-threshold`` is counted over 5 minute intervals.
-
 =============================================== ========= =========================== ==========================================
 Option                                          Type      Default                     Comment
 =============================================== ========= =========================== ==========================================
@@ -93,7 +91,8 @@ increase-throttled-by-provisioned-writes-scale  ``dict``
                                                                                       Detailed information on the scale dict can be found `here <http://dynamic-dynamodb.readthedocs.org/en/latest/granular_scaling.html>`__.
 increase-writes-unit                            ``str``   ``percent``                 Set if we should scale up in ``units`` or ``percent``
 increase-writes-with                            ``int``   50                          Number of ``units`` or ``percent`` we should scale up the write provisioning with. Choose entity with ``increase-writes-unit``.
-lookback-window-start                           ``int``   15                          Dynamic DynamoDB fetches data from CloudWatch in a window that streches between ``now()-15`` and ``now()-10`` minutes. If you want to look at slightly newer data, change this value. Please note that it might not be set to less than 5 minutes (as CloudWatch data for DynamoDB is updated every 5 minutes).
+lookback-window-start                           ``int``   15                          Dynamic DynamoDB fetches data from CloudWatch in a window that streches between ``now()-15`` and ``now()-10`` minutes. If you want to look at slightly newer data, change this value. Please note that it might not be set to less than 1 minute (as CloudWatch data for DynamoDB is updated every minute).
+lookback-period                                 ``int``   5                           Changes the duration of CloudWatch data to look at. For example, instead of looking at ``now()-15`` to ``now()-10``, you can look at ``now()-15`` to ``now()-14``
 maintenance-windows                             ``str``                               Force Dynamic DynamoDB to operate within maintenance windows. E.g. ``22:00-23:59,00:00-06:00``
 max-provisioned-reads                           ``int``                               Maximum number of provisioned reads for the table
 max-provisioned-writes                          ``int``                               Maximum number of provisioned writes for the table
@@ -129,8 +128,6 @@ Important note: Both the GSI name and the table name is treated as regular expre
 
 The ``table:`` section after ``gsi:`` **must** match with an existing ``table:`` section.
 
-Please note also that DynamoDB writes CloudWatch data every 5 minutes, thus ``reads/writes-upper/lower-threshold`` and ``throttled-reads/writes-upper-threshold`` is counted over 5 minute intervals.
-
 =============================================== ========= =========================== ==========================================
 Option                                          Type      Default                     Comment
 =============================================== ========= =========================== ==========================================

diff --git a/docs/release_notes.rst b/docs/release_notes.rst
@@ -1,14 +1,21 @@
 Release notes
 =============
 
-2.0.2
+2.1.0
 -----
 
 **Release date:** 2015-09-30
 
-- Use HTTP rather than SSH for git clone (`#266 <https://github.com/sebdah/dynamic-dynamodb/issues/266>`). Thanks for the pull request `@superprat <https://github.com/superprat>`
+- Support for granular downscaling (`#263 <https://github.com/sebdah/dynamic-dynamodb/issues/263>`). Thanks for the pull request `@Sazpaimon <https://github.com/Sazpaimon>`
+- Allow configurable lookback period instead of the hardcoded 5 minute one (`#261 <https://github.com/sebdah/dynamic-dynamodb/issues/261>`). Thanks for the pull request `@Sazpaimon <https://github.com/Sazpaimon>`
+- Don't scale down if it would scale below the current consumed units (`#268 <https://github.com/sebdah/dynamic-dynamodb/issues/261>`). Thanks for the pull request `@Sazpaimon <https://github.com/Sazpaimon>`
 
+2.0.2
+-----
 
+**Release date:** 2015-09-30
+
+- Use HTTP rather than SSH for git clone (`#266 <https://github.com/sebdah/dynamic-dynamodb/issues/266>`). Thanks for the pull request `@superprat <https://github.com/superprat>`
 
 2.0.1
 -----

diff --git a/dynamic_dynamodb/calculators.py b/dynamic_dynamodb/calculators.py
@@ -339,6 +339,25 @@ def increase_writes_in_units(
     return updated_provisioning
 
 
+def is_consumed_over_proposed(
+        current_provisioning, proposed_provisioning, consumed_units_percent):
+    """
+    Determines if the currently consumed capacity is over the proposed capacity
+    for this table
+
+    :type current_provisioning: int
+    :param current_provisioning: The current provisioning
+    :type proposed_provisioning: int
+    :param proposed_provisioning: New provisioning
+    :type consumed_units_percent: float
+    :param consumed_units_percent: Percent of consumed units
+    :returns: bool - if consumed is over max
+    """
+    consumption_based_current_provisioning = \
+        int(math.ceil(current_provisioning*(consumed_units_percent/100)))
+    return consumption_based_current_provisioning > proposed_provisioning
+
+
 def __get_min_reads(current_provisioning, min_provisioned_reads, log_tag):
     """ Get the minimum number of reads to current_provisioning
 

diff --git a/dynamic_dynamodb/config/__init__.py b/dynamic_dynamodb/config/__init__.py
@@ -70,6 +70,7 @@
         'allow_scaling_down_writes_on_0_percent': False,
         'always_decrease_rw_together': False,
         'lookback_window_start': 15,
+        'lookback_period': 5,
         'maintenance_windows': None,
         'sns_topic_arn': None,
         'sns_message_types': [],
@@ -86,7 +87,13 @@
         'increase_throttled_by_consumed_reads_unit': None,
         'increase_throttled_by_consumed_reads_scale': None,
         'increase_throttled_by_consumed_writes_unit': None,
-        'increase_throttled_by_consumed_writes_scale': None
+        'increase_throttled_by_consumed_writes_scale': None,
+        'decrease_consumed_reads_unit': None,
+        'decrease_consumed_reads_with': None,
+        'decrease_consumed_reads_scale': None,
+        'decrease_consumed_writes_unit': None,
+        'decrease_consumed_writes_with': None,
+        'decrease_consumed_writes_scale': None,
     },
     'gsi': {
         'reads-upper-alarm-threshold': 0,
@@ -125,6 +132,7 @@
         'allow_scaling_down_writes_on_0_percent': False,
         'always_decrease_rw_together': False,
         'lookback_window_start': 15,
+        'lookback_period': 5,
         'maintenance_windows': None,
         'sns_topic_arn': None,
         'sns_message_types': [],
@@ -405,10 +413,10 @@ def __check_gsi_rules(configuration):
                 sys.exit(1)
 
             # Check lookback-window start
-            if gsi['lookback_window_start'] < 5:
+            if gsi['lookback_window_start'] < 1:
                 print(
-                    'lookback-window-start must be a value higher than 5, '
-                    'as DynamoDB sends CloudWatch data every 5 minutes')
+                    'lookback-window-start must be a value higher than 1, '
+                    'as DynamoDB sends CloudWatch data every minute')
                 sys.exit(1)
 
             # Check sns-message-types
@@ -440,13 +448,17 @@ def __check_gsi_rules(configuration):
                 'min_provisioned_writes',
                 'max_provisioned_writes',
                 'increase_consumed_reads_with',
-                'increase_consumed_writes_with'
+                'increase_consumed_writes_with',
+                'decrease_consumed_reads_with',
+                'decrease_consumed_writes_with'
             ]
             # Config options without a mandatory default
             # should be allowed a None value
             non_default = [
                 'increase_consumed_reads_with',
-                'increase_consumed_writes_with'
+                'increase_consumed_writes_with',
+                'decrease_consumed_reads_with',
+                'decrease_consumed_writes_with'
             ]
 
             for option in options:
@@ -567,10 +579,10 @@ def __check_table_rules(configuration):
             sys.exit(1)
 
         # Check lookback-window start
-        if table['lookback_window_start'] < 5:
+        if table['lookback_window_start'] < 1:
             print(
-                'lookback-window-start must be a value higher than 5, '
-                'as DynamoDB sends CloudWatch data every 5 minutes')
+                'lookback-window-start must be a value higher than 1, '
+                'as DynamoDB sends CloudWatch data every minute')
             sys.exit(1)
 
         # Check sns-message-types

diff --git a/dynamic_dynamodb/config/config_file_parser.py b/dynamic_dynamodb/config/config_file_parser.py
@@ -246,6 +246,12 @@
         'required': False,
         'type': 'int'
     },
+    {
+        'key': 'lookback_period',
+        'option': 'lookback-period',
+        'required': False,
+        'type': 'int'
+    },
     {
         'key': 'increase_throttled_by_provisioned_reads_unit',
         'option': 'increase-throttled-by-provisioned-reads-unit',
@@ -329,6 +335,42 @@
         'option': 'increase-consumed-writes-scale',
         'required': False,
         'type': 'dict'
+    },
+    {
+        'key': 'decrease_consumed_reads_unit',
+        'option': 'decrease-consumed-reads-unit',
+        'required': False,
+        'type': 'str'
+    },
+    {
+        'key': 'decrease_consumed_reads_with',
+        'option': 'decrease-consumed-reads-with',
+        'required': False,
+        'type': 'int'
+    },
+    {
+        'key': 'decrease_consumed_reads_scale',
+        'option': 'decrease-consumed-reads-scale',
+        'required': False,
+        'type': 'dict'
+    },
+    {
+        'key': 'decrease_consumed_writes_unit',
+        'option': 'decrease-consumed-writes-unit',
+        'required': False,
+        'type': 'str'
+    },
+    {
+        'key': 'decrease_consumed_writes_with',
+        'option': 'decrease-consumed-writes-with',
+        'required': False,
+        'type': 'int'
+    },
+    {
+        'key': 'decrease_consumed_writes_scale',
+        'option': 'decrease-consumed-writes-scale',
+        'required': False,
+        'type': 'dict'
     }
 ]