WIP for #24 - Made field key list use pagination and added tests

graphite-api.yaml.example

@@ -199,12 +199,14 @@ influxdb:
   # 
   # Row limit of series loader queries
   # 
+  # Should _not_ exceed max-row-limit setting of InfluxDB
+  # 
   # Depending on InfluxDB data and machine memory sizes, this may need to be
   # lowered to avoid InfluxDB returning partial results due to not enough 
   # available memory.
   # 
   # Example query: SHOW SERIES LIMIT <loader_limit> <..>
-  # loader_limit: 100000
+  # loader_limit: 10000
 
   # 
   ## Fill function parameter to use on data queries

influxgraph/classes/finder.py

@@ -1,5 +1,5 @@
-# Copyright (C) [2015-] [Thomson Reuters LLC]
-# Copyright (C) [2015-] [Panos Kittenis]
+# Copyright (C) [2015-2017] [Thomson Reuters LLC]
+# Copyright (C) [2015-2017] [Panos Kittenis]
 
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -627,20 +627,37 @@ def load_index(self):
         self.index = index
         logger.info("Loaded index from disk")
 
-    def get_field_keys(self):
-        """Get field keys for all measurements"""
-        field_keys = self.memcache.get(_MEMCACHE_FIELDS_KEY) \
+    def get_all_field_keys(self, offset=0, field_keys=None):
+        """Get all field keys from DB, starting at offset"""
+        field_keys = {} if field_keys is None else field_keys
+        cur_field_keys = self.get_field_keys(offset=offset)
+        if len(cur_field_keys.keys()) == 0:
+            return field_keys
+        for key in cur_field_keys:
+            field_keys.setdefault(key, deque()).extend(cur_field_keys[key])
+        return self.get_all_field_keys(
+            offset=self.loader_limit + offset,
+            field_keys=field_keys)
+
+    def get_field_keys(self, offset=0):
+        """Get one field keys list at offset"""
+        memcache_key = gen_memcache_pattern_key("_".join([
+            _MEMCACHE_FIELDS_KEY, str(self.loader_limit), str(offset)]))
+        field_keys = self.memcache.get(memcache_key) \
           if self.memcache else None
         if field_keys:
-            logger.debug("Found cached field keys")
+            logger.debug("Found cached field keys list for limit %s, offset %s",
+                         self.loader_limit, offset,)
             return field_keys
-        logger.debug("Calling InfluxDB for field keys")
-        data = self.client.query('SHOW FIELD KEYS')
+        logger.debug("Calling InfluxDB for field keys with limit %s, offset %s",
+                     self.loader_limit, offset,)
+        data = self.client.query('SHOW FIELD KEYS LIMIT %s OFFSET %s' % (
+            self.loader_limit, offset,))
         field_keys = {}
         for ((key, _), vals) in data.items():
             field_keys[key] = [val['fieldKey'] for val in vals]
         if self.memcache:
-            if not self.memcache.set(_MEMCACHE_FIELDS_KEY, field_keys,
+            if not self.memcache.set(memcache_key, field_keys,
                                      time=self.memcache_ttl,
                                      min_compress_len=1):
                 logger.error("Could not add field key list to memcache - "

tests/test_influxdb_templates_integration.py

@@ -6,13 +6,18 @@
 import datetime
 import time
 from random import randint
+import logging
 import influxdb.exceptions
 import influxgraph
-from influxgraph.utils import Query
+from influxgraph.utils import Query, make_memcache_client, gen_memcache_pattern_key
 from influxgraph.constants import SERIES_LOADER_MUTEX_KEY, \
      MEMCACHE_SERIES_DEFAULT_TTL, LOADER_LIMIT, _MEMCACHE_FIELDS_KEY
 from influxdb import InfluxDBClient
 from influxgraph.templates import InvalidTemplateError
+from influxgraph.classes.finder import logger as finder_logger
+
+finder_logger.setLevel(logging.DEBUG)
+logging.basicConfig()
 
 os.environ['TZ'] = 'UTC'
 
@@ -1038,6 +1043,51 @@ def test_multi_tmpl_part_filter(self):
         for metric in cpu_data:
             self.assertTrue(cpu_data[metric][-1] == fields[metric.split('.')[-1]])
 
+    def test_field_list_pagination(self):
+        del self.finder
+        measurements = ['m1', 'm2', 'm3']
+        fields = {'f1': self.randval(),
+                  'f2': self.randval(),
+                  'f3': self.randval(),
+                  'f4': self.randval()}
+        tags = {'t1': 't1_val'}
+        self.client.drop_database(self.db_name)
+        self.client.create_database(self.db_name)
+        self.write_data(measurements, tags, fields)
+        m4_measurement = 'm4'
+        m4_fields = {'f5': self.randval()}
+        self.write_data([m4_measurement], tags, m4_fields)
+        m5_measurement= 'm5'
+        m5_fields = {'f5': self.randval(),
+                     'f6': self.randval(),
+                     'f7': self.randval(),
+                     'f8': self.randval(),
+                     'f9': self.randval(),
+                     'f10': self.randval(),
+                     }
+        self.write_data([m5_measurement], tags, m5_fields)
+        self.config['influxdb']['loader_limit'] = 1
+        self.finder = influxgraph.InfluxDBFinder(self.config)
+        fields_page1 = self.finder.get_field_keys()
+        self.assertEqual(len(fields_page1.values()[0]), self.finder.loader_limit)
+        all_db_fields = self.finder.get_all_field_keys()
+        for measurement in measurements:
+            self.assertEqual(len(all_db_fields[measurement]), len(fields.keys()))
+        self.assertEqual(len(all_db_fields['m4']), len(m4_fields.keys()))
+        self.assertEqual(len(all_db_fields['m5']), len(m5_fields.keys()))
+        # Memcached test
+        self.config['influxdb']['memcache'] = {'host': 'localhost'}
+        memcache_client = make_memcache_client(
+            self.config['influxdb']['memcache']['host'])
+        for offset in range(len(m5_fields.keys())):
+            memcache_key = gen_memcache_pattern_key("_".join([
+                _MEMCACHE_FIELDS_KEY, str(
+                    self.config['influxdb']['loader_limit']), str(offset)]))
+            memcache_client.delete(memcache_key)
+        self.finder = influxgraph.InfluxDBFinder(self.config)
+        self.finder.get_all_field_keys()
+        cached_db_fields = self.finder.get_all_field_keys()
+        self.assertEqual(all_db_fields, cached_db_fields)
 
 if __name__ == '__main__':
     unittest.main()