Adding a max thread count to protect the db on hosts with a lot of cpus

Author: timvaillancourt

MongoBackup/Methods/Dumper.py

@@ -67,12 +67,15 @@ def wait(self):
             raise Exception, "Not all mongodump threads completed successfully!", None
 
     def run(self):
-        # decide how many parallel dump workers to use based on cpu count vs # of shards (if 3.2+)
-        self.threads_per_dump = 0
+        # decide how many parallel dump workers to use based on cpu count vs # of shards (if 3.2+), 8 max workers max to protect the db
+        self.threads_per_dump     = 0
+        self.threads_per_dump_max = 8
         if tuple(self.version.split(".")) >= tuple("3.2.0".split(".")): 
             self.threads_per_dump = 1
             if self.cpu_count > len(self.secondaries):
                 self.threads_per_dump = int(floor(self.cpu_count / len(self.secondaries)))
+            if self.threads_per_dump > self.threads_per_dump_max:
+                self.threads_per_dump = self.threads_per_dump_max
         else:
             logging.warn("Threading unsupported by mongodump version %s. Use mongodump 3.2.0 or greater to enable per-dump threading." % self.version)