diff --git a/run_tests.sh b/run_tests.sh
index 2f51771..1233d2e 100755
--- a/run_tests.sh
+++ b/run_tests.sh
@@ -58,7 +58,7 @@ export PATH=$base:$PATH
 
 function run_tests() {
 	current_dir=$(pwd)
-	for test in $(find tests -name 'test*.sh' | sort); do 
+	for test in $(find tests -name 'test*.sh' | sort | grep "$ONLY"); do 
 		mkdir -p $workdir/$test
 		cd $workdir/$test
 		echo Running tests/$test ...
@@ -70,4 +70,3 @@ function run_tests() {
 }
 
 run_tests
-
diff --git a/sender b/sender
index f1790f7..c99bae1 100755
--- a/sender
+++ b/sender
@@ -17,12 +17,14 @@ import threading
 import Queue
 import signal
 import traceback
+import json
 
 DEFAULT_SIGNAGURE_LENGTH=256
 
 filter_stopped = Queue.Queue()
 stop_signal = Queue.Queue()
 running_lock = threading.Lock()
+debug_on = False
 
 def should_stop():
 	return not stop_signal.empty()
@@ -36,6 +38,7 @@ def main():
 		"IMPORTANT: only files with size >= signature-length (default %d) bytes will be processed. "
 		"Zip files will be open recursively, and only once." % DEFAULT_SIGNAGURE_LENGTH)
 
+	parser.add_option('-D', '--debug', action="store_true", dest="debug", help="Enable debug output", default=False)
 	parser.add_option('-f', '--follow', action="store_true", dest="follow", help="Pools the file very second for changes in an infinite loop.", default=False)
 	parser.add_option('-p', '--offsets', action="store", dest="offsets", help="File to persist the last offsets read for each file. If it doesn't exist, the files are read from beginning.", default='/dev/null')
 	parser.add_option('-t', '--tcp', action="store", dest="host", help="Sends the output to the host:port via TCP.", metavar="HOST:PORT")
@@ -49,6 +52,11 @@ def main():
 
 	options, args = parser.parse_args()
 
+	if options.debug:
+		log("DEBUG ON")
+		global debug_on
+		debug_on = True
+
 	if options.dump_pid:
 		f = open(options.dump_pid,'w')
 		f.write("%d" % os.getpid())
@@ -153,6 +161,8 @@ def log(msg):
 	sys.stderr.flush()
 
 def debug(msg):
+	if debug_on:
+		log("DEBUG: "+ msg);
 	# sys.stderr.write(str(msg))
 	# sys.stderr.write("\n")
 	# sys.stderr.flush()
@@ -264,6 +274,8 @@ class Tail(object):
 		self.starting = options.starting
 		self.start_from_tail = options.start_from_tail
 		self.readOffsets()
+		self.duplicates = {}
+
 
 	def persistOffsets(self):
 		if self.offsetsfn == '/dev/null':
@@ -319,6 +331,7 @@ class Tail(object):
 		if should_stop():
 			return
 		for line in f:
+			if debug_on: debug("line %s" % line.replace("\n",""))
 			if not self.starting or line >= self.starting:
 				self.output.write(line)
 			if should_stop():
@@ -355,7 +368,7 @@ class Tail(object):
 			self.processZipFile(f, fn)
 
 	def processGzipFile(self, fn):
-		debug("gz: %s" % fn)
+		if debug_on: debug("gz: %s" % fn)
 		f = gzip.open(fn)
 		try:
 			self.processFile(f, '/var/tmp/fake.log', {})
@@ -369,46 +382,41 @@ class Tail(object):
 		shutil.rmtree(path)
 
 	def processFileByName(self, fn, existing):
-		debug("processFileByName: %s" % fn)
+		if debug_on: debug("processFileByName: %s" % fn)
 		f = open(fn, 'rb')
 		try:
 			self.processFile(f, fn, existing)
 		finally:
 			f.close()
+			debug("processFileByName, close file");
 
-	def processFile(self, f, fn, existing):
-		debug("processFile: %s" % fn)
-		sig = self.generateSignature(f)
-		if not sig:
-			return
-
-		if sig in existing and os.path.getsize(fn) != os.path.getsize(existing[sig]):
-			log("WARN Files '%s' and '%s' have same signature and different sizes" % (fn, existing[sig]))
-
+	def processFile(self, f, fn, sig):
 		info = self.offsets.get(sig, Info(sig=sig, name=fn))
+		if debug_on: debug("processFile %s  %s" % (fn, info.dump()))
 
 		lastOffset = info.offset
-
 		info.name = fn
 
 		if self.isCompressed(fn):
-			debug("compressed: %s" % fn)
+			if debug_on: debug("compressed: %s" % fn)
 			if info.offset == 0:
 				if not self.start_from_tail:
 					self.processCompressedFile(f, fn)
 				info.offset = -1
 		else:
 			if self.start_from_tail:
+				if debug_on: debug("starting from tail %s" % fn)
 				info.offsets = os.path.getsize(fn)
 			if os.path.exists(fn) and os.path.getsize(fn) < info.offset:
-				log("WARN file %s was truncated" % fn)
+				log("METRIC ns=forwarder.truncated file=%s filesize=%s offset=%s" % (fn, os.path.getsize(fn), info.offset))
 				info.offset = os.path.getsize(fn)
 			else:
+				if debug_on: debug("Seeking to %s in %s, currently at %s" % (info.offset, fn, f.tell()))
 				f.seek(info.offset)
 				self.copy(f)
 				info.offset = f.tell()
+				if debug_on: debug("Setting offset for: %s to %s (info: %s)" % (fn, info.offset, info.dump()))
 
-		existing[sig] = fn
 
 		if lastOffset != info.offset:
 			self.offsets[sig] = info
@@ -422,23 +430,64 @@ class Tail(object):
 				if not filter_stopped.empty():
 					sys.exit(1)
 				existing = {}
+				to_process = {}
+				filehandles = {}
 				for fnpattern in self.fnpatterns:
 					for fn in glob.glob(fnpattern):
+						if debug_on: debug("Checking fn %s" % fn)
+						f = None
 						try:
 							if not os.path.isfile(fn):
 								log("File no longer exists: %s" % fn)
 								continue
 							if os.path.getsize(fn) < self.signatureLength and not self.isCompressed(fn):
+								log("Skipping as file too short to generate sig or file is compressed: %s" % fn)
 								continue
-							self.processFileByName(fn, existing)
+							f = open(fn, 'rb')
+							sig = self.generateSignature(f)
+							if debug_on: debug("Sig for fn %s is %s" % (fn, sig))
+							sig_fn = sig+fn;
+							if sig in existing:
+								if not sig_fn in self.duplicates:
+									log("METRIC ns=forwarder.duplicatesig file=%s dupe_of=%s sig=%s" % (fn, existing[sig], sig))
+									self.duplicates[sig_fn] = True;
+								if sig in to_process: #take original duplicate out of to_process
+									del to_process[sig]
+								f.close()
+							else:
+								if debug_on: debug("Adding file %s %s" % (fn, sig))
+								existing[sig] = fn #leave in existing in case more than 2 duplicates
+								to_process[sig] = fn
+								filehandles[sig] = f
+
 						except Exception, e:
-							log("Exception: %s" % e)
+							log("METRIC ns=forwarder.error.preprocess file=\"%s\" exception=\"%s\"" % (fn, str(e).replace("\n", "")))
+							log("Exception=\"%s\"" % e)
+							if f: f.close()
 							exc_type, exc_value, exc_traceback = sys.exc_info()
 							traceback.print_tb(exc_traceback)
 
 
+				if debug_on: debug("To Process %s" % to_process)
+				sigs = to_process.keys()
+				for sig in sigs:
+					f = None
+					try:
+						fn = to_process[sig]
+						if debug_on: debug("Processing file %s %s" % (fn, sig))
+						f = filehandles[sig]
+						self.processFile(f, fn, sig)
+					except Exception, e:
+						log("METRIC ns=forwarder.error.process file=\"%s\" exception=\"%s\"" % (fn, str(e).replace("\n", "")))
+						log("Exception=\"%s\"" % e)
+						exc_type, exc_value, exc_traceback = sys.exc_info()
+						traceback.print_tb(exc_traceback)
+						f.close()
+					finally:
+						if f and not f.closed: f.close()
+
 				if len(existing) != len(self.offsets):
-					self.purgeOffsetsNotIn(existing)
+					self.purgeOffsetsNotIn(to_process)
 				if not self.follow:
 					break
 				time.sleep(1)
diff --git a/tests/test-kill-int-forwarder.sh b/tests/test-kill-int-forwarder.sh
index 87ae499..ae78c3c 100755
--- a/tests/test-kill-int-forwarder.sh
+++ b/tests/test-kill-int-forwarder.sh
@@ -5,10 +5,11 @@ uuid=$(last_uuid)
 
 sender -f 'myapp.*' -l "grep --line-buffered -v ${uuid}" > /dev/null &
 sender_pid=$!
-sleep 0.1 # to avoid race condition
+sleep 1 # to avoid race condition
 
 assert "ps ax | grep ${uuid} | grep -v sender | grep -v filter_wrapper | grep line-buffered | count_lines" 1
 
+
 kill -SIGINT $sender_pid
 
 wait $sender_pid
diff --git a/tests/test-kill-term-forwarder.sh b/tests/test-kill-term-forwarder.sh
index 1b6b512..4572bae 100755
--- a/tests/test-kill-term-forwarder.sh
+++ b/tests/test-kill-term-forwarder.sh
@@ -5,7 +5,7 @@ uuid=$(last_uuid)
 
 sender -f 'myapp.*' -l "grep --line-buffered -v ${uuid}" > /dev/null &
 sender_pid=$!
-sleep 0.1 # to avoid race condition
+sleep 1 # to avoid race condition
 
 assert "ps ax | grep ${uuid} | grep -v sender | grep -v filter_wrapper | grep line-buffered | count_lines" 1
 
diff --git a/tests/test-signature-size.sh b/tests/test-signature-size.sh
index 97dce52..17df4f0 100644
--- a/tests/test-signature-size.sh
+++ b/tests/test-signature-size.sh
@@ -1,5 +1,14 @@
 echo "AAAAAAAAAAAAAAAAAA BBBBBBBBBBBBBBB" > myapp.log
 echo "AAAAAAAAAAAAAAAAAA CCCCCCCCCCCCCCC" > myapp.log.1
 
-assert "sender -s 15 'myapp.*' | count_lines" 1
+assert "sender -s 15 'myapp.*' | count_lines" 0
 assert "sender -s 30 'myapp.*' | count_lines" 2
+
+echo "AAAAAAAAAAAAAAAAAA DDDDDDDDDDDDDDD" > myapp.log.2
+echo "AAAAAAAAAAAAAAAAAA DDDDDDDDDDDDDDD" > myapp.log.3
+echo "AAAAAAAAAAAAAAAAAA DDDDDDDDDDDDDDD" > myapp.log.4
+echo "AAAAAAAAAAAAAAAAAA DDDDDDDDDDDDDDD" > myapp.log.5
+
+assert "sender -s 30 'myapp.*' | count_lines" 2
+
+assert "sender -s 30 'myapp.*' 2>&1 | grep forwarder.duplicatesig | count_lines" 3
diff --git a/tests/test-tcp-raw.sh b/tests/test-tcp-raw.sh
index 6c0feb4..03b966c 100644
--- a/tests/test-tcp-raw.sh
+++ b/tests/test-tcp-raw.sh
@@ -1,10 +1,10 @@
 for i in {1..10}; do log_random >> myapp.log; done
 
-nc -l -p 19501 2>/dev/null > received.log || nc -l 19501 > received.log 2>/dev/null & 
+nc -l -p 19501 2>/dev/null > received.log || nc -l 19501 > received.log 2>/dev/null &
 
 server_pid=$!
 
-sleep 0.1
+sleep 1
 
 sender 'myapp.*' -t localhost:19501