diff --git a/scripts/globusmonitor/Dockerfile_uploader b/scripts/globusmonitor/Dockerfile_uploader
index 6af94f04..9792d18a 100644
--- a/scripts/globusmonitor/Dockerfile_uploader
+++ b/scripts/globusmonitor/Dockerfile_uploader
@@ -6,7 +6,9 @@ RUN apt-get -y update \
     && pip install flask-restful \
         python-logstash \
         globusonline-transfer-api-client \
-        psycopg2
+        psycopg2 python-etcd
+
+
 
 COPY *.py *.json /home/globusmonitor/
 
diff --git a/scripts/globusmonitor/globus_uploader_service.py b/scripts/globusmonitor/globus_uploader_service.py
index 2efeea60..eb3fc837 100644
--- a/scripts/globusmonitor/globus_uploader_service.py
+++ b/scripts/globusmonitor/globus_uploader_service.py
@@ -12,9 +12,11 @@
 import signal
 import psycopg2
 import socket
+import re
 from psycopg2.extensions import ISOLATION_LEVEL_AUTOCOMMIT
 from io import BlockingIOError
 from urllib3.filepost import encode_multipart_formdata
+import etcd, traceback
 
 from pyclowder.datasets import download_metadata
 from terrautils.metadata import clean_metadata
@@ -50,6 +52,8 @@
 current_task = None
 
 
+etcd_client = etcd.Client(host='etcd2.terraref', port=4001)
+
 # ----------------------------------------------------------
 # SHARED UTILS
 # ----------------------------------------------------------
@@ -208,7 +212,7 @@ def writeTaskToDatabase(task):
     recv = task['received']
     comp = task['completed']
     guser = task['user']
-    jbody = json.dumps(task['contents'])
+    jbody = json.dumps(task['contents']).replace("'", "")
 
     # Attempt to insert, update if globus ID already exists
     q_insert = "INSERT INTO globus_tasks (globus_id, status, received, completed, globus_user, contents) " \
@@ -384,6 +388,13 @@ def notifyClowderOfCompletedTask(task):
                     c_sensor, c_date, c_year, c_month = ds, None, None, None
 
 
+
+                lockname = re.sub(" |_|-", "", ds)
+                logger.info("Acquiring lock for task %s" % lockname)
+                lock = etcd.Lock(etcd_client, lockname)
+                lock.acquire(blocking=True, lock_ttl=300, timeout=60)
+                logger.info("Acquired lock")
+
                 # Get dataset from clowder, or create & associate with collections
                 try:
                     hierarchy_host = clowder_host + ("/" if not clowder_host.endswith("/") else "")
@@ -396,6 +407,10 @@ def notifyClowderOfCompletedTask(task):
                     response = "RETRY"
                     continue
 
+                logger.info("Releasing lock")
+                lock.release()
+                logger.info("Lock released")
+
                 if dsid:
                     dsFileList = fetchDatasetFileList(dsid, sess)
                     # Only send files not already present in dataset by path
@@ -479,7 +494,7 @@ def notifyClowderOfCompletedTask(task):
                                        headers={'Content-Type':header},
                                        data=content)
 
-                        if fi.status_code in [104, 500, 502, 504]:
+                        if fi.status_code in [500, 502, 504]:
                             logger.error("[%s] failed to attach files (%s: %s)" % (ds, fi.status_code, fi.text))
                             updatedTask['contents'][ds]['files'][datasetMDFile]['retry'] = "%s: %s" % (fi.status_code, fi.text)
                             response = "RETRY"
@@ -552,6 +567,11 @@ def clowderSubmissionLoop():
                         logger.error("Connection reset on %s; marking RETRY (%s)" % (globusID, str(e)))
                         task['status'] = 'RETRY'
                         writeTaskToDatabase(task)
+                except etcd.EtcdException as e:
+                    logger.error("Lock error on %s; marking RETRY (%s)" % (globusID, str(e)))
+                    task['status'] = 'RETRY'
+                    traceback.print_exc()
+                    writeTaskToDatabase(task)
                 except requests.ConnectionError as e:
                     logger.error("Connection error on %s; marking RETRY (%s)" % (globusID, str(e)))
                     task['status'] = 'RETRY'
@@ -589,6 +609,11 @@ def clowderSubmissionLoop():
                         logger.error("Connection reset on %s; marking RETRY (%s)" % (globusID, str(e)))
                         task['status'] = 'RETRY'
                         writeTaskToDatabase(task)
+                except etcd.EtcdException as e:
+                    logger.error("Lock error on %s; marking RETRY (%s)" % (globusID, str(e)))
+                    task['status'] = 'RETRY'
+                    traceback.print_exc()
+                    writeTaskToDatabase(task)
                 except requests.ConnectionError as e:
                     logger.error("Connection error on %s; marking RETRY (%s)" % (globusID, str(e)))
                     task['status'] = 'RETRY'