Implements #945: monitor Redis key lengths

checks.d/redisdb.py

@@ -177,6 +177,19 @@ def _check_db(self, instance, custom_tags=None):
         self.rate('redis.net.commands', info['total_commands_processed'],
                   tags=tags)
 
+        # Check some key lengths if asked
+        key_list = instance.get('keys')
+        if not isinstance(key_list, list) or len(key_list) == 0:
+            self.warning("keys in redis configuration is either not a list or empty")
+        else:
+            l_tags = list(tags)
+            for key in key_list:
+                if conn.exists(key):
+                    key_tags = l_tags + ["key:" + key]
+                    self.gauge("redis.key.length", conn.llen(key), tags=key_tags)
+                else:
+                    self.warning("{0} key not found in redis".format(key))
+
     def check(self, instance):
         try:
             import redis

conf.d/redisdb.yaml.example

@@ -7,4 +7,7 @@ instances:
 #       password: mypassword
 #       tags:
 #            - optional_tag1
-#            - optional_tag2
+#            - optional_tag2
+#       keys: # check the length of these keys
+#            - key1
+#            - key2