Disable memory consumption watcher by default

agent.py

@@ -139,7 +139,8 @@ def _get_emitters(self, agentConfig):
     def _get_watchdog(self, check_freq, agentConfig):
         watchdog = None
         if agentConfig.get("watchdog", True):
-            watchdog = Watchdog(check_freq * WATCHDOG_MULTIPLIER)
+            watchdog = Watchdog(check_freq * WATCHDOG_MULTIPLIER, 
+                max_mem_mb=agentConfig.get('limit_memory_consumption', None))
             watchdog.reset()
         return watchdog
 

config.py

@@ -371,6 +371,12 @@ def get_config(parse_args=True, cfg_path=None, options=None):
             for key, value in config.items('WMI'):
                 agentConfig['WMI'][key] = value
 
+        if config.has_option("Main", "limit_memory_consumption") and \
+            config.get("Main", "limit_memory_consumption") is not None:
+            agentConfig["limit_memory_consumption"] = int(config.get("Main", "limit_memory_consumption"))
+        else:
+            agentConfig["limit_memory_consumption"] = None
+
     except ConfigParser.NoSectionError, e:
         sys.stderr.write('Config file not found or incorrectly formatted.\n')
         sys.exit(2)

ddagent.py

@@ -310,7 +310,8 @@ def __init__(self, port, agentConfig, watchdog=True):
         self._watchdog = None
         if watchdog:
             watchdog_timeout = TRANSACTION_FLUSH_INTERVAL * WATCHDOG_INTERVAL_MULTIPLIER
-            self._watchdog = Watchdog(watchdog_timeout)
+            self._watchdog = Watchdog(watchdog_timeout,
+                max_mem_mb=agentConfig.get('limit_memory_consumption', None))
 
     def log_request(self, handler):
         """ Override the tornado logging method.

util.py

@@ -258,17 +258,21 @@ class Watchdog(object):
     Can only be invoked once per process, so don't use with multiple threads.
     If you instantiate more than one, you're also asking for trouble.
     """
-    def __init__(self, duration, max_mem_mb = 2000):
+    def __init__(self, duration, max_mem_mb = None):
         import resource
 
         #Set the duration
         self._duration = int(duration)
         signal.signal(signal.SIGALRM, Watchdog.self_destruct)
 
         # cap memory usage
-        self._max_mem_kb = 1024 * max_mem_mb
-        max_mem_bytes = 1024 * self._max_mem_kb
-        resource.setrlimit(resource.RLIMIT_AS, (max_mem_bytes, max_mem_bytes))
+        if max_mem_mb is not None:
+            self._max_mem_kb = 1024 * max_mem_mb
+            max_mem_bytes = 1024 * self._max_mem_kb
+            resource.setrlimit(resource.RLIMIT_AS, (max_mem_bytes, max_mem_bytes))
+            self.memory_limit_enabled = True
+        else:
+            self.memory_limit_enabled = False
 
     @staticmethod
     def self_destruct(signum, frame):
@@ -283,7 +287,7 @@ def self_destruct(signum, frame):
     def reset(self):
         # self destruct if using too much memory, as tornado will swallow MemoryErrors
         mem_usage_kb = int(os.popen('ps -p %d -o %s | tail -1' % (os.getpid(), 'rss')).read())
-        if mem_usage_kb > (0.95 * self._max_mem_kb):
+        if self.memory_limit_enabled and mem_usage_kb > (0.95 * self._max_mem_kb):
             Watchdog.self_destruct(signal.SIGKILL, sys._getframe(0))
 
         log.debug("Resetting watchdog for %d" % self._duration)