From 634684669e63707e0217ec0f36e77bf71f6b6a8f 2014-02-11 12:51:05
From: chapmanb <chapmanb@50mail.com>
Date: 2014-02-11 12:51:05
Subject: [PATCH] Provide logging messages in ipcluster log when engine or controllers fail to start (chapmanb/bcbio-nextgen#298

---

diff --git a/IPython/parallel/apps/ipclusterapp.py b/IPython/parallel/apps/ipclusterapp.py
index e80d057..8777bad 100755
--- a/IPython/parallel/apps/ipclusterapp.py
+++ b/IPython/parallel/apps/ipclusterapp.py
@@ -348,7 +348,11 @@ class IPClusterEngines(BaseParallelApplication):
         # Some EngineSetLaunchers ignore `n` and use their own engine count, such as SSH:
         n = getattr(self.engine_launcher, 'engine_count', self.n)
         self.log.info("Starting %s Engines with %s", n, self.engine_launcher_class)
-        self.engine_launcher.start(self.n)
+        try:
+            self.engine_launcher.start(self.n)
+        except:
+            self.log.exception("Engine start failed")
+            raise
         self.engine_launcher.on_stop(self.engines_stopped_early)
         if self.early_shutdown:
             ioloop.DelayedCallback(self.engines_started_ok, self.early_shutdown*1000, self.loop).start()
@@ -517,7 +521,11 @@ class IPClusterStart(IPClusterEngines):
     def start_controller(self):
         self.log.info("Starting Controller with %s", self.controller_launcher_class)
         self.controller_launcher.on_stop(self.stop_launchers)
-        self.controller_launcher.start()
+        try:
+            self.controller_launcher.start()
+        except:
+            self.log.exception("Controller start failed")
+            raise
 
     def stop_controller(self):
         # self.log.info("In stop_controller")