diff --git a/README.md b/README.md
index ad54e13f0..11c7aae74 100644
--- a/README.md
+++ b/README.md
@@ -82,7 +82,7 @@ Both the web-interface, and the programmatic-api, have corresponding
 ### Web Interface
 
 The [web-interface](https://github.com/jeff1evesque/machine-learning/blob/master/interface/templates/index.html),
- can be accessed within the browser on `https://192.168.99.101:8080`:
+ can be accessed within the browser on `https://192.168.99.101:8585`:
 
 ![web-interface](https://user-images.githubusercontent.com/2907085/39499223-97b96fce-4d7a-11e8-96e2-c4e31f6b8e09.JPG 'web-interface')
 
@@ -135,7 +135,7 @@ A post request, can be implemented in python, as follows:
 ```python
 import requests
 
-endpoint = 'https://192.168.99.101:9090/load-data'
+endpoint = 'https://192.168.99.101:9595/load-data'
 headers = {
     'Authorization': 'Bearer ' + token,
     'Content-Type': 'application/json'
@@ -151,6 +151,6 @@ requests.post(endpoint, headers=headers, data=json_string_here)
 
 It is important to remember that the [`docker-compose.development.yml`](https://github.com/jeff1evesque/machine-learning/blob/3889788a8343a4b7cef2cf84166f9bd35d83021c/docker-compose.development.yml#L33-L43),
  has defined two port forwards, each assigned to its corresponding reverse
- proxy. This allows port `8080` on the host, to map into the `webserver-web`
- container. A similar case for the programmatic-api, uses port `9090` on the
+ proxy. This allows port `8585` on the host, to map into the `webserver-web`
+ container. A similar case for the programmatic-api, uses port `9595` on the
  host.
diff --git a/brain/cache/hset.py b/brain/cache/hset.py
index fee199099..51e813815 100644
--- a/brain/cache/hset.py
+++ b/brain/cache/hset.py
@@ -9,15 +9,13 @@
 from brain.cache.query import Query
 
 
-class Hset(object):
+class Hset:
     '''
 
     This class provides an interface to cache, and uncache the redis hash
     data structure.  Specifically, necessary data components is passed into the
     corresponding class method.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self):
@@ -36,7 +34,7 @@ def __init__(self):
         # start redis client
         try:
             self.myRedis.start_redis()
-        except Exception, error:
+        except Exception as error:
             self.list_error.append(str(error))
 
     def cache(self, hash_name, key, value):
@@ -48,9 +46,9 @@ def cache(self, hash_name, key, value):
 
         try:
             self.myRedis.hset(hash_name, key, value)
-        except Exception, error:
+        except Exception as error:
             self.list_error.append(str(error))
-            print self.list_error
+            print(self.list_error)
 
     def uncache(self, hash_name, key):
         '''
@@ -61,6 +59,6 @@ def uncache(self, hash_name, key):
 
         try:
             return {'result': self.myRedis.hget(hash_name, key), 'error': None}
-        except Exception, error:
+        except Exception as error:
             self.list_error.append(str(error))
             return {'result': None, 'error': self.list_error}
diff --git a/brain/cache/model.py b/brain/cache/model.py
index 0aeec757c..f5a9fdecd 100644
--- a/brain/cache/model.py
+++ b/brain/cache/model.py
@@ -10,7 +10,7 @@
 from brain.converter.model import Model as Converter
 
 
-class Model(object):
+class Model:
     '''
 
     This class provides an interface to cache, and uncache the redis hash
@@ -18,8 +18,6 @@ class Model(object):
     corresponding class method, which allow computed model(s) to be stored into
     a NoSQL datastore.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self, model=None):
@@ -39,7 +37,7 @@ def __init__(self, model=None):
         # start redis client
         try:
             self.myRedis.start_redis()
-        except Exception, error:
+        except Exception as error:
             self.list_error.append(str(error))
 
     def cache(self, hash_name, key):
@@ -53,9 +51,9 @@ def cache(self, hash_name, key):
         try:
             serialized = Converter(self.model).serialize()
             self.myRedis.hset(hash_name, key, serialized)
-        except Exception, error:
+        except Exception as error:
             self.list_error.append(str(error))
-            print self.list_error
+            print(self.list_error)
 
     def uncache(self, hash_name, key):
         '''
@@ -96,6 +94,6 @@ def get_all_titles(self, name):
                     'error': 'no previous model found in cache'
                 }
 
-        except Exception, error:
+        except Exception as error:
             self.list_error.append(str(error))
             return {'result': None, 'error': self.list_error}
diff --git a/brain/cache/query.py b/brain/cache/query.py
index 9d83f1a8f..4446369b9 100644
--- a/brain/cache/query.py
+++ b/brain/cache/query.py
@@ -10,7 +10,7 @@
 from brain.cache.settings import Settings
 
 
-class Query(object):
+class Query:
     '''
 
     This class provides an interface to various Redis data structures.
@@ -32,8 +32,6 @@ class Query(object):
           concept to 'lists'. Also, the above included redis data structures,
           provides enough flexibility to accomplish most requirements.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self, db_num=0, host=None, port=None):
diff --git a/brain/cache/settings.py b/brain/cache/settings.py
index 2c2dad0c3..c686cfe58 100644
--- a/brain/cache/settings.py
+++ b/brain/cache/settings.py
@@ -9,14 +9,12 @@
 from flask import current_app
 
 
-class Settings(object):
+class Settings:
     '''
 
     This class provides an interface to get, or set the redis host, or redis
     port.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self):
diff --git a/brain/converter/model.py b/brain/converter/model.py
index ed99e9540..abf908438 100644
--- a/brain/converter/model.py
+++ b/brain/converter/model.py
@@ -10,14 +10,12 @@
 from sklearn import svm, preprocessing
 
 
-class Model(object):
+class Model:
     '''
 
     This class provides an interface to serialize, and deserialize an SVM
     object.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self, model):
diff --git a/brain/converter/operation.py b/brain/converter/operation.py
index c9d727099..3820db338 100644
--- a/brain/converter/operation.py
+++ b/brain/converter/operation.py
@@ -9,15 +9,13 @@
 '''
 
 
-class Operation(object):
+class Operation:
     '''
 
     This class provides an interface to restructure the supplied data into a
     consistent structure, which allows successive parsers to implement
     corresponding logic.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self, settings, dataset=None):
diff --git a/brain/converter/settings.py b/brain/converter/settings.py
index 6d27ca280..bd02345e5 100644
--- a/brain/converter/settings.py
+++ b/brain/converter/settings.py
@@ -9,15 +9,13 @@
 '''
 
 
-class Settings(object):
+class Settings:
     '''
 
     This class provides an interface to restructure the supplied data into a
     consistent structure, which allows successive parsers to implement
     corresponding logic.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self, settings, dataset=None):
diff --git a/brain/database/account.py b/brain/database/account.py
index dd0e6010e..0b551d4a3 100644
--- a/brain/database/account.py
+++ b/brain/database/account.py
@@ -10,13 +10,11 @@
 from brain.database.query import SQL
 
 
-class Account(object):
+class Account:
     '''
 
     This class provides an interface to the users account.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self):
@@ -71,7 +69,7 @@ def check_username(self, username):
         sql_statement = 'SELECT * '\
             'FROM tbl_user '\
             'WHERE username=%s'
-        args = (username)
+        args = (username,)
         response = self.sql.execute('select', sql_statement, args)
 
         # retrieve any error(s)
@@ -95,7 +93,7 @@ def check_email(self, email):
         sql_statement = 'SELECT * '\
             'FROM tbl_user '\
             'WHERE email=%s'
-        args = (email)
+        args = (email,)
         response = self.sql.execute('select', sql_statement, args)
 
         # retrieve any error(s)
@@ -119,7 +117,7 @@ def get_password(self, username):
         sql_statement = 'SELECT password '\
             'FROM tbl_user '\
             'WHERE username=%s'
-        args = (username)
+        args = (username,)
         response = self.sql.execute('select', sql_statement, args)
 
         # retrieve any error(s)
@@ -143,7 +141,7 @@ def get_uid(self, username):
         sql_statement = 'SELECT id_user '\
             'FROM tbl_user '\
             'WHERE username=%s'
-        args = (username)
+        args = (username,)
         response = self.sql.execute('select', sql_statement, args)
 
         # retrieve any error(s)
diff --git a/brain/database/dataset.py b/brain/database/dataset.py
index a6291036b..3c5f86c27 100644
--- a/brain/database/dataset.py
+++ b/brain/database/dataset.py
@@ -10,7 +10,7 @@
 from brain.database.query import NoSQL
 
 
-class Collection(object):
+class Collection:
     '''
 
     This class provides an interface to retrieve, and store various parameters,
@@ -18,8 +18,6 @@ class Collection(object):
 
     Note: this class is invoked within 'base_data.py'
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self):
@@ -55,6 +53,12 @@ def query(self, collection, operation, payload=None):
         if operation == 'drop_collection':
             self.nosql.connect()
             response = self.nosql.execute(operation, collection)
+
+        elif operation == 'count_documents':
+            self.nosql.connect(collection)
+            response = self.nosql.execute(operation, payload)
+            response['result'] = int(response['result'] or 0)
+
         else:
             self.nosql.connect(collection)
             response = self.nosql.execute(operation, payload)
diff --git a/brain/database/entity.py b/brain/database/entity.py
index baef961ef..a9acdbb2f 100644
--- a/brain/database/entity.py
+++ b/brain/database/entity.py
@@ -10,7 +10,7 @@
 from brain.database.query import SQL
 
 
-class Entity(object):
+class Entity:
     '''
 
     This class provides an interface to save, retrieve an SVM entity title,
@@ -19,8 +19,6 @@ class Entity(object):
     Note: this class is invoked within 'model_generate.py', 'base_data.py',
           and 'data_append.py'
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self, premodel_data=None, session_type=None):
@@ -106,7 +104,7 @@ def get_title(self, id_entity):
         sql_statement = 'SELECT title '\
             'FROM tbl_dataset_entity '\
             'WHERE id_entity=%s'
-        args = (id_entity)
+        args = (id_entity,)
         response = self.sql.execute('select', sql_statement, args)
 
         # retrieve any error(s)
@@ -135,7 +133,7 @@ def get_collections(self, uid):
             'FROM tbl_dataset_entity '\
             'WHERE uid_created=%s '\
             'ORDER BY datetime_created'
-        args = (uid)
+        args = (uid,)
         response = self.sql.execute('select', sql_statement, args)
 
         # retrieve any error(s)
@@ -166,7 +164,7 @@ def get_collection_count(self, uid):
             'FROM tbl_dataset_entity '\
             'WHERE uid_created=%s'\
             ') AS c'
-        args = (uid)
+        args = (uid,)
         response = self.sql.execute('select', sql_statement, args)
 
         # retrieve any error(s)
@@ -176,7 +174,7 @@ def get_collection_count(self, uid):
         if response_error:
             return {'error': response_error, 'result': None}
         else:
-            return {'error': None, 'result': int(response['result'][0][0])}
+            return {'error': None, 'result': int(response['result'][0][0] or 0)}
 
     def remove_entity(self, uid, collection):
         '''
diff --git a/brain/database/model_type.py b/brain/database/model_type.py
index 3af415b4e..e0009cd23 100644
--- a/brain/database/model_type.py
+++ b/brain/database/model_type.py
@@ -10,7 +10,7 @@
 from brain.database.query import SQL
 
 
-class ModelType(object):
+class ModelType:
     '''
 
     Note: this class explicitly inherits the 'new-style' class.
@@ -20,7 +20,7 @@ class ModelType(object):
     def __init__(self):
         '''
 
-        This constructor is responsible for defining class variables.
+        This class provides and interface between the model_type.
 
         '''
 
@@ -49,7 +49,7 @@ def get_model_type(self, collection):
             ' INNER JOIN tbl_model_type mtype'\
             ' ON mid.model_type = mtype.id_model'\
             ' WHERE mid.collection=%s'
-        args = (collection)
+        args = (collection,)
         response = self.sql.execute('select', sql_statement, args)
 
         # retrieve any error(s)
diff --git a/brain/database/prediction.py b/brain/database/prediction.py
index 47889b6f0..e132a3672 100644
--- a/brain/database/prediction.py
+++ b/brain/database/prediction.py
@@ -10,14 +10,12 @@
 from brain.database.query import SQL
 
 
-class Prediction(object):
+class Prediction:
     '''
 
     This class provides an interface to save, or retrieve, a previously
     generated svm or, svr prediction result.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self):
@@ -79,14 +77,14 @@ def save(self, data, model_type, title):
                 sql_statement = 'INSERT INTO tbl_svm_results_probability '\
                     '(id_result, probability) VALUES(%s, %s)'
                 args = (svm_results['id'], x)
-                self.sql.execute('insert', sql_statement, args,)
+                self.sql.execute('insert', sql_statement, args)
 
             # svm decision function
             for x in decision_function:
                 sql_statement = 'INSERT INTO tbl_svm_results_decision_function '\
                     '(id_result, decision_function) VALUES(%s, %s)'
-                args = (svm_results['id'], x,)
-                self.sql.execute('insert', sql_statement, args,)
+                args = (svm_results['id'], x)
+                self.sql.execute('insert', sql_statement, args)
 
         elif model_type == 'svr':
             # svr results
@@ -94,13 +92,13 @@ def save(self, data, model_type, title):
                 '(model_type, title, result, uid_created, datetime_created) '\
                 'VALUES(%s, %s, %s, %s, UTC_TIMESTAMP())'
             args = (self.model_list.index(model_type) + 1, title, result, self.uid)
-            svr_results = self.sql.execute('insert', sql_statement, args,)
+            svr_results = self.sql.execute('insert', sql_statement, args)
 
             # svr r2
             sql_statement = 'INSERT INTO tbl_svr_results_r2 '\
                 '(id_result, r2) VALUES(%s, %s)'
             args = (svr_results['id'], data['r2'])
-            self.sql.execute('insert', sql_statement, args,)
+            self.sql.execute('insert', sql_statement, args)
 
         # retrieve any error(s)
         response_error = self.sql.get_errors()
@@ -139,7 +137,7 @@ def get_all_titles(self, model_type=None):
             sql_statement = 'SELECT id_result, title, datetime_created '\
                 'FROM tbl_prediction_results '\
                 'WHERE uid_created=%s'
-            args = (self.uid)
+            args = (self.uid,)
             response = self.sql.execute('select', sql_statement, args)
 
         # retrieve any error(s)
diff --git a/brain/database/query.py b/brain/database/query.py
index df52b4162..ce72e6301 100644
--- a/brain/database/query.py
+++ b/brain/database/query.py
@@ -66,14 +66,12 @@ def get_mongodb():
     return g.mongodb
 
 
-class NoSQL(object):
+class NoSQL:
     '''
 
     This class provides an interface to connect, execute commands, and
     disconnect from a NoSQL database.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self):
@@ -108,7 +106,7 @@ def connect(self, collection=None):
                 'error': None,
             }
 
-        except errors, error:
+        except Exception as error:
             self.proceed = False
             self.list_error.append(error)
 
@@ -168,7 +166,7 @@ def execute(self, operation, payload):
                 elif operation == 'drop_collection':
                     result = self.database.drop_collection(payload)
 
-            except errors, error:
+            except Exception as error:
                 self.list_error.append(error)
 
                 return {
@@ -197,7 +195,7 @@ def disconnect(self):
                     'error': None,
                 }
 
-            except errors, error:
+            except Exception as error:
                 self.list_error.append(error)
 
                 return {
@@ -215,14 +213,12 @@ def get_errors(self):
         return self.list_error
 
 
-class SQL(object):
+class SQL:
     '''
 
     This class provides an interface to connect, execute commands, and
     disconnect from a SQL database.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self, host=None, user=None, passwd=None):
@@ -300,7 +296,7 @@ def execute(self, operation, statement, sql_args=None):
                         'result': result,
                     }
 
-            except MariaClient.Error, error:
+            except MariaClient.Error as error:
                 self.conn.rollback()
                 self.list_error.append(error)
 
@@ -329,7 +325,7 @@ def disconnect(self):
                         'id': self.cursor.lastrowid,
                     }
 
-            except MariaClient.Error, error:
+            except MariaClient.Error as error:
                 self.list_error.append(error)
 
                 return {
diff --git a/brain/database/session.py b/brain/database/session.py
index f8b6ed56b..717750356 100644
--- a/brain/database/session.py
+++ b/brain/database/session.py
@@ -10,7 +10,7 @@
 from brain.database.query import SQL
 
 
-class Session(object):
+class Session:
     '''
 
     This class provides an interface to retrieve the 'id_entity', and
@@ -18,8 +18,6 @@ class Session(object):
 
     Note: this class is invoked within 'views.py'
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self):
@@ -44,7 +42,7 @@ def get_session_id(self, collection):
         self.sql.connect(self.db_ml)
         sql_statement = 'SELECT id_entity FROM tbl_dataset_entity '\
             'WHERE collection=%s'
-        args = (collection)
+        args = (collection,)
         response = self.sql.execute('select', sql_statement, args)
 
         # retrieve any error(s)
diff --git a/brain/database/settings.py b/brain/database/settings.py
index 3105529f2..f7f114ea8 100644
--- a/brain/database/settings.py
+++ b/brain/database/settings.py
@@ -9,7 +9,7 @@
 from flask import current_app
 
 
-class Database(object):
+class Database:
     '''
 
     This class provides an interface to get, or set the following database
@@ -33,9 +33,7 @@ class Database(object):
             -> DATABASES ON *.* TO 'authenticated'@'localhost';
         MariaDB> FLUSH PRIVILEGES;
 
-    Note: this class is invoked within 'query.py'
-
-    Note: this class explicitly inherits the 'new-style' class.
+    Note: this class is invoked within 'query.py'.
 
     '''
 
diff --git a/brain/load_data.py b/brain/load_data.py
index 48d47d451..613cb0034 100644
--- a/brain/load_data.py
+++ b/brain/load_data.py
@@ -16,7 +16,7 @@
 from brain.database.session import Session
 
 
-class Load_Data(object):
+class Load_Data:
     '''
 
     This class provides an interface to load the necessary parameters:
@@ -26,8 +26,6 @@ class Load_Data(object):
               from the SQL database.
         - generate a prediction using a previous cached model.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self, data, uid=None):
diff --git a/brain/session/base.py b/brain/session/base.py
index e0179a99a..66cb1386c 100644
--- a/brain/session/base.py
+++ b/brain/session/base.py
@@ -14,7 +14,7 @@
 from brain.validator.settings import Validator
 
 
-class Base(object):
+class Base:
     '''
 
     This class provides a general base class, used for the following sessions,
@@ -25,9 +25,7 @@ class Base(object):
         - model_generate
         - model_predict
 
-    Note: this class is invoked within 'data_xx.py', 'model_xx.py'
-
-    Note: this class explicitly inherits the 'new-style' class.
+    Note: this class is invoked within 'data_xx.py', 'model_xx.py'.
 
     '''
 
diff --git a/brain/session/base_data.py b/brain/session/base_data.py
index fb55e6d4b..3afe13c04 100644
--- a/brain/session/base_data.py
+++ b/brain/session/base_data.py
@@ -71,7 +71,7 @@ def validate_id(self, session_id):
         try:
             if not int(session_id) > 0:
                 self.list_error.append(error)
-        except Exception, error:
+        except Exception as error:
             self.list_error.append(str(error))
 
     def save_premodel_dataset(self):
@@ -97,6 +97,7 @@ def save_premodel_dataset(self):
         if (
             not self.uid and
             collection_count and
+            collection_count['result'] and
             collection_count['result'] >= self.max_collection and
             collection_adjusted
         ):
@@ -129,6 +130,21 @@ def save_premodel_dataset(self):
                     document
                 )
 
+            current_utc = datetime.datetime.utcnow().strftime("%Y-%m-%dT%H:%M:%S")
+            self.premodel_data['properties']['datetime_saved'] = current_utc
+
+            if self.dataset:
+                document = {
+                    'properties': self.premodel_data['properties'],
+                    'dataset': self.dataset
+                }
+
+                response = cursor.query(
+                    collection_adjusted,
+                    'insert_one',
+                    document
+                )
+
         else:
             response = None
 
diff --git a/brain/session/data_append.py b/brain/session/data_append.py
index b23e26e23..253abadb9 100644
--- a/brain/session/data_append.py
+++ b/brain/session/data_append.py
@@ -77,7 +77,7 @@ def save_entity(self, session_type, session_id):
             'id_entity': session_id,
         }
 
-        # store entity values in database
+        # store entity values
         if (
             collection_adjusted and
             collection_count and
diff --git a/brain/session/data_new.py b/brain/session/data_new.py
index 51af82b83..fc9aec260 100644
--- a/brain/session/data_new.py
+++ b/brain/session/data_new.py
@@ -79,7 +79,7 @@ def save_entity(self, session_type, id_entity=None):
             'uid': self.uid,
         }
 
-        # store entity values in database
+        # store entity values
         if (
             collection_adjusted and
             collection_count and
diff --git a/brain/validator/dataset.py b/brain/validator/dataset.py
index f3c59a2be..9db0929ab 100644
--- a/brain/validator/dataset.py
+++ b/brain/validator/dataset.py
@@ -6,18 +6,17 @@
 
 '''
 
-from voluptuous import Schema, Required, All, Any, Length
+from voluptuous import Schema, Required, All, Any, Length, Coerce
 from voluptuous.humanize import validate_with_humanized_errors
+from six import string_types
 
 
-class Validator(object):
+class Validator:
     '''
 
     This class provides an interface to validate provided dataset(s) during
     'data_new', and 'data_append' sessions.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self):
@@ -38,17 +37,18 @@ def validate_classification(self, data):
 
         current_errors = []
         schema = Schema({
-            Required('dependent-variable'): All(unicode, Length(min=1)),
+            Required('dependent-variable'): All(string_types[0], Length(min=1)),
             Required('independent-variables'): [{
-                Required(All(unicode, Length(min=1))): Any(int, float),
+                Required(All(string_types[0], Length(min=1))): Coerce(float),
             }],
+            Required('error'): Any(None, string_types[0]),
         })
 
         for instance in data:
             try:
                 validate_with_humanized_errors(instance, schema)
 
-            except Exception, error:
+            except Exception as error:
                 split_error = str(error).splitlines()
                 current_errors.extend(split_error)
                 self.list_error.extend(split_error)
@@ -67,17 +67,18 @@ def validate_regression(self, data):
 
         current_errors = []
         schema = Schema({
-            Required('dependent-variable'): Any(int, float),
+            Required('dependent-variable'): Coerce(float),
             Required('independent-variables'): [{
-                Required(All(unicode, Length(min=1))): Any(int, float),
+                Required(All(string_types[0], Length(min=1))): Coerce(float),
             }],
+            Required('error'): Any(None, string_types[0]),
         })
 
         for instance in data:
             try:
                 validate_with_humanized_errors(instance, schema)
 
-            except Exception, error:
+            except Exception as error:
                 split_error = str(error).splitlines()
                 current_errors.extend(split_error)
                 self.list_error.extend(split_error)
@@ -97,7 +98,7 @@ def validate_value(self, data):
         try:
             return float(data)
 
-        except Exception, error:
+        except Exception as error:
             self.list_error.append(error)
             return error
 
diff --git a/brain/validator/settings.py b/brain/validator/settings.py
index a042c4053..e71f5ac9a 100644
--- a/brain/validator/settings.py
+++ b/brain/validator/settings.py
@@ -9,16 +9,15 @@
 from flask import current_app
 from voluptuous import Schema, Required, Optional, All, Any, Coerce, In, Length
 from voluptuous.humanize import validate_with_humanized_errors
+from six import string_types
 
 
-class Validator(object):
+class Validator:
     '''
 
     This class provides an interface to validate the settings for each
     session.
 
-    Note: this class explicitly inherits the 'new-style' class.
-
     '''
 
     def __init__(self):
@@ -50,17 +49,17 @@ def validate_settings(self, premodel_settings, session_type):
         if session_type in ['data_new', 'data_append']:
             if premodel_settings['stream'] == 'True' or session_type == 'data_new':
                 schema = Schema({
-                    Required('collection'): All(unicode, Length(min=1)),
+                    Required('collection'): All(string_types[0], Length(min=1)),
                     Required('dataset_type'): In(dataset_type),
                     Required('model_type'): In(model_type),
                     Required('session_type'): Any('data_new', 'data_append'),
-                    Required('session_name'): All(unicode, Length(min=1)),
+                    Required('session_name'): All(string_types[0], Length(min=1)),
                     Optional('stream'): Any('True', 'False'),
                 })
 
             else:
                 schema = Schema({
-                    Required('collection'): All(unicode, Length(min=1)),
+                    Required('collection'): All(string_types[0], Length(min=1)),
                     Required('dataset_type'): In(dataset_type),
                     Required('model_type'): In(model_type),
                     Required('session_type'): Any('data_new', 'data_append'),
@@ -70,7 +69,7 @@ def validate_settings(self, premodel_settings, session_type):
         # validation on 'model_generate' session
         if session_type == 'model_generate':
             schema = Schema({
-                Required('collection'): All(unicode, Length(min=1)),
+                Required('collection'): All(string_types[0], Length(min=1)),
                 Required('model_type'): In(model_type),
                 Required('session_type'): 'model_generate',
                 Optional('stream'): Any('True', 'False'),
@@ -82,7 +81,7 @@ def validate_settings(self, premodel_settings, session_type):
         # validation on 'model_predict' session
         elif session_type == 'model_predict':
             schema = Schema({
-                Required('collection'): All(unicode, Length(min=1)),
+                Required('collection'): All(string_types[0], Length(min=1)),
                 Optional('stream'): Any('True', 'False'),
                 Required('prediction_input[]'): [
                     Any(Coerce(int), Coerce(float)),
@@ -93,7 +92,7 @@ def validate_settings(self, premodel_settings, session_type):
         try:
             validate_with_humanized_errors(premodel_settings, schema)
 
-        except Exception, error:
+        except Exception as error:
             split_error = str(error).splitlines()
             self.list_error.append(split_error)
             return split_error
diff --git a/dockerfile/base.dockerfile b/dockerfile/base.dockerfile
index b0afc42ab..a2172fe9c 100644
--- a/dockerfile/base.dockerfile
+++ b/dockerfile/base.dockerfile
@@ -1,31 +1,29 @@
 FROM ubuntu:16.04
 
 ## environment variables
-ENV ENVIRONMENT docker
-ENV PUPPET /opt/puppetlabs/bin/puppet
-ENV ROOT_PROJECT /var/machine-learning
-ENV ROOT_PUPPET /etc/puppetlabs
+ENV ENVIRONMENT=docker\
+    PUPPET=/opt/puppetlabs/bin/puppet\
+    ROOT_PROJECT=/var/machine-learning\
+    ROOT_PUPPET=/etc/puppetlabs\
+    PUPPET_VERSION=puppet5-release-xenial.deb
+ENV MODULES=$ROOT_PUPPET/code/modules\
+    CONTRIB_MODULES=$ROOT_PUPPET/code/modules_contrib\
+    ENVPATH=$ROOT_PUPPET/code/environment/$ENVIRONMENT
 
 ## ensure directory
 RUN mkdir -p $ROOT_PROJECT/log $ROOT_PUPPET/code/environment/$ENVIRONMENT $ROOT_PUPPET/puppet/hiera $ROOT_PUPPET/code/modules_contrib
 
-## environment variables
-ENV MODULES $ROOT_PUPPET/code/modules
-ENV CONTRIB_MODULES $ROOT_PUPPET/code/modules_contrib
-ENV ENVPATH $ROOT_PUPPET/code/environment/$ENVIRONMENT
-
-## install git, wget
+##
+## install git, wget, puppet
 ##
 ##  Note: r10k requires 'git' installed
 ##
 RUN apt-get -y update
-RUN apt-get -y install git=1:1.9.1* wget=1.16*
-
-## install puppet
-RUN wget https://apt.puppetlabs.com/puppetlabs-release-pc1-trusty.deb
-RUN dpkg -i puppetlabs-release-pc1-trusty.deb
+RUN apt-get -y install wget=1.17* curl=7.47*
+RUN wget https://apt.puppetlabs.com/$PUPPET_VERSION
+RUN dpkg -i $PUPPET_VERSION
 RUN apt-get -y update
-RUN apt-get -y install puppet-agent
+RUN apt-get -y install git=1:2.7.4-0ubuntu* puppet-agent=5.5*
 
 ## copy configs
 COPY puppet/environment/$ENVIRONMENT/Puppetfile $ENVPATH
@@ -39,13 +37,11 @@ COPY hiera.yaml $ROOT_PUPPET/puppet
 ##
 ##       https://github.com/jeff1evesque/machine-learning/issues/2991
 ##
-RUN apt-get -y install rubygems-integration=1.5
-RUN gem install semantic_puppet -v 0.1.0
-RUN gem install puppet_forge -v 2.2.5
-RUN gem install r10k -v 2.5.5
+RUN apt-get -y install ruby=1:2.3* rubygems-integration=1.10
+RUN gem install semantic_puppet:0.1.0 puppet_forge:2.2.9 r10k:3.0.2
 
 ## install puppet modules using puppetfile with r10k
-RUN PUPPETFILE=$ENVPATH/Puppetfile PUPPETFILE_DIR=$CONTRIB_MODULES r10k puppetfile install
+RUN r10k puppetfile install --puppetfile $ENVPATH/Puppetfile --moduledir $CONTRIB_MODULES
 
 ## provision with puppet
 RUN $PUPPET apply apply -e 'class { system: }' --modulepath=$CONTRIB_MODULES:$MODULES --confdir=$ROOT_PUPPET/puppet
diff --git a/dockerfile/mariadb.dockerfile b/dockerfile/mariadb.dockerfile
index 115c857bf..69d4cf5a6 100644
--- a/dockerfile/mariadb.dockerfile
+++ b/dockerfile/mariadb.dockerfile
@@ -1,10 +1,10 @@
-FROM jeff1evesque/ml-base:0.7
+FROM jeff1evesque/ml-base:0.8
 
 ## local variables
 ENV ENVIRONMENT=docker\
     PUPPET=/opt/puppetlabs/bin/puppet\
-    ROOT_PUPPET=/etc/puppetlabs\
-    MODULES=$ROOT_PUPPET/code/modules\
+    ROOT_PUPPET=/etc/puppetlabs
+ENV MODULES=$ROOT_PUPPET/code/modules\
     CONTRIB_MODULES=$ROOT_PUPPET/code/modules_contrib
 
 ## copy files into container
@@ -16,11 +16,21 @@ RUN apt-get update && $PUPPET apply -e 'class { mariadb: }'\
     --modulepath=$CONTRIB_MODULES:$MODULES\
     --confdir=$ROOT_PUPPET/puppet
 
+##
 ## define entrypoint script
+##
+## @mysqlclient, requires 'apt-get' + 'pip3' dependencies only during runtime:
+##
+##     - https://raspberrypi.stackexchange.com/a/78217.
+##
 RUN printf '#!/bin/bash\n\n\
 cd $MODULES/mariadb/scripts\n\
 service mysql start\n\
-python setup_tables.py $ROOT_PUPPET/puppet\n\
+apt-get install -y python3-dev libmysqlclient-dev\n\
+pip3 install mysqlclient\n\
+python3 setup_tables.py $ROOT_PUPPET/puppet\n\
+apt-get remove -y python3-dev libmysqlclient-dev\n\
+pip3 uninstall -y mysqlclient\n\
 service mysql stop\n\
 mysqld\n\
 ' > entrypoint
diff --git a/dockerfile/mongodb.dockerfile b/dockerfile/mongodb.dockerfile
index 7d582f55f..716612ebf 100644
--- a/dockerfile/mongodb.dockerfile
+++ b/dockerfile/mongodb.dockerfile
@@ -1,11 +1,11 @@
-FROM jeff1evesque/ml-base:0.7
+FROM jeff1evesque/ml-base:0.8
 
 ## local variables
-ENV ENVIRONMENT docker
-ENV PUPPET /opt/puppetlabs/bin/puppet
-ENV ROOT_PUPPET /etc/puppetlabs
-ENV MODULES $ROOT_PUPPET/code/modules
-ENV CONTRIB_MODULES $ROOT_PUPPET/code/modules_contrib
+ENV ENVIRONMENT=docker\
+    PUPPET=/opt/puppetlabs/bin/puppet\
+    ROOT_PUPPET=/etc/puppetlabs
+ENV MODULES=$ROOT_PUPPET/code/modules\
+    CONTRIB_MODULES=$ROOT_PUPPET/code/modules_contrib
 
 ## copy files into container
 COPY hiera $ROOT_PUPPET/puppet/hiera
diff --git a/dockerfile/nginx.dockerfile b/dockerfile/nginx.dockerfile
index 77aff03ae..9cb224c7b 100644
--- a/dockerfile/nginx.dockerfile
+++ b/dockerfile/nginx.dockerfile
@@ -1,12 +1,13 @@
-FROM jeff1evesque/ml-base:0.7
+FROM jeff1evesque/ml-base:0.8
 
 ## local variables
-ENV ENVIRONMENT docker
-ENV ROOT_PROJECT /var/machine-learning
-ENV PUPPET /opt/puppetlabs/bin/puppet
-ENV ROOT_PUPPET /etc/puppetlabs
-ENV MODULES $ROOT_PUPPET/code/modules
-ENV CONTRIB_MODULES $ROOT_PUPPET/code/modules_contrib
+ENV ENVIRONMENT=docker\
+    ROOT_PROJECT=/var/machine-learning\
+    PUPPET=/opt/puppetlabs/bin/puppet\
+    ROOT_PUPPET=/etc/puppetlabs
+ENV MODULES=$ROOT_PUPPET/code/modules\
+    CONTRIB_MODULES=$ROOT_PUPPET/code/modules_contrib
+
 ARG TYPE
 ARG VHOST
 ARG HOST_PORT
@@ -21,14 +22,14 @@ COPY puppet/environment/$ENVIRONMENT/modules/reverse_proxy $ROOT_PUPPET/code/mod
 ##
 ## provision with puppet: either build a web, or api nginx image.
 ##
-##     docker build --build-arg TYPE=api --build-arg RUN=false --build-arg VHOST=machine-learning-api.com --build-arg HOST_PORT=9090 --build-arg LISTEN_PORT=6000 -f nginx.dockerfile -t jeff1evesque/ml-nginx-api:0.7 .
-##     docker build --build-arg TYPE=web --build-arg RUN=false --build-arg VHOST=machine-learning-web.com --build-arg HOST_PORT=9090 --build-arg LISTEN_PORT=6000 -f nginx.dockerfile -t jeff1evesque/ml-nginx-web:0.7 .
+##     docker build --build-arg TYPE=api --build-arg RUN=false --build-arg VHOST=machine-learning-api.com --build-arg LISTEN_PORT=6000 -f nginx.dockerfile -t jeff1evesque/ml-nginx-api:0.8 .
+##     docker build --build-arg TYPE=web --build-arg RUN=false --build-arg VHOST=machine-learning-web.com --build-arg LISTEN_PORT=5000 -f nginx.dockerfile -t jeff1evesque/ml-nginx-web:0.8 .
 ##
-##     docker build --build-arg TYPE=api --build-arg RUN=false -f nginx.dockerfile -t jeff1evesque/ml-nginx-api:0.7 .
-##     docker build --build-arg TYPE=web --build-arg RUN=false -f nginx.dockerfile -t jeff1evesque/ml-nginx-web:0.7 .
+##     docker build --build-arg TYPE=api --build-arg RUN=false -f nginx.dockerfile -t jeff1evesque/ml-nginx-api:0.8 .
+##     docker build --build-arg TYPE=web --build-arg RUN=false -f nginx.dockerfile -t jeff1evesque/ml-nginx-web:0.8 .
 ##
-##     docker run --hostname nginx-api --name nginx-api -d jeff1evesque/ml-nginx-api:0.7
-##     docker run --hostname nginx-web --name nginx-web -d jeff1evesque/ml-nginx-web:0.7
+##     docker run --hostname nginx-api --name nginx-api -d jeff1evesque/ml-nginx-api:0.8
+##     docker run --hostname nginx-web --name nginx-web -d jeff1evesque/ml-nginx-web:0.8
 ##
 RUN $PUPPET apply -e "class { reverse_proxy: \
     run => 'false', \
diff --git a/dockerfile/redis.dockerfile b/dockerfile/redis.dockerfile
index 9282a7918..46ebd1ecd 100644
--- a/dockerfile/redis.dockerfile
+++ b/dockerfile/redis.dockerfile
@@ -1,11 +1,11 @@
-FROM jeff1evesque/ml-base:0.7
+FROM jeff1evesque/ml-base:0.8
 
 ## local variables
-ENV ENVIRONMENT docker
-ENV PUPPET /opt/puppetlabs/bin/puppet
-ENV ROOT_PUPPET /etc/puppetlabs
-ENV MODULES $ROOT_PUPPET/code/modules
-ENV CONTRIB_MODULES $ROOT_PUPPET/code/modules_contrib
+ENV ENVIRONMENT=docker\
+    PUPPET=/opt/puppetlabs/bin/puppet\
+    ROOT_PUPPET=/etc/puppetlabs
+ENV MODULES=$ROOT_PUPPET/code/modules\
+    CONTRIB_MODULES=$ROOT_PUPPET/code/modules_contrib
 
 ## copy files into container
 COPY hiera $ROOT_PUPPET/puppet/hiera
diff --git a/dockerfile/sklearn.dockerfile b/dockerfile/sklearn.dockerfile
index b14a49e04..3640e07a4 100644
--- a/dockerfile/sklearn.dockerfile
+++ b/dockerfile/sklearn.dockerfile
@@ -1,12 +1,12 @@
-FROM jeff1evesque/ml-base:0.7
+FROM jeff1evesque/ml-base:0.8
 
 ## local variables
-ENV ENVIRONMENT docker
-ENV PUPPET /opt/puppetlabs/bin/puppet
-ENV ROOT_PROJECT /var/machine-learning
-ENV ROOT_PUPPET /etc/puppetlabs
-ENV MODULES $ROOT_PUPPET/code/modules
-ENV CONTRIB_MODULES $ROOT_PUPPET/code/modules_contrib
+ENV ENVIRONMENT=docker\
+    PUPPET=/opt/puppetlabs/bin/puppet\
+    ROOT_PROJECT=/var/machine-learning\
+    ROOT_PUPPET=/etc/puppetlabs
+ENV MODULES=$ROOT_PUPPET/code/modules\
+    CONTRIB_MODULES=$ROOT_PUPPET/code/modules_contrib
 
 ## copy files into container
 COPY hiera $ROOT_PROJECT/hiera
diff --git a/dockerfile/webserver.dockerfile b/dockerfile/webserver.dockerfile
index 18003fdb4..3f5c23fa3 100644
--- a/dockerfile/webserver.dockerfile
+++ b/dockerfile/webserver.dockerfile
@@ -1,12 +1,12 @@
-FROM jeff1evesque/ml-sklearn:0.7
+FROM jeff1evesque/ml-sklearn:0.8
 
 ## local variables
-ENV ENVIRONMENT docker
-ENV PUPPET /opt/puppetlabs/bin/puppet
-ENV ROOT_PROJECT /var/machine-learning
-ENV ROOT_PUPPET /etc/puppetlabs
-ENV MODULES $ROOT_PUPPET/code/modules
-ENV CONTRIB_MODULES $ROOT_PUPPET/code/modules_contrib
+ENV ENVIRONMENT=docker\
+    PUPPET=/opt/puppetlabs/bin/puppet\
+    ROOT_PROJECT=/var/machine-learning\
+    ROOT_PUPPET=/etc/puppetlabs
+ENV MODULES=$ROOT_PUPPET/code/modules\
+    CONTRIB_MODULES=$ROOT_PUPPET/code/modules_contrib
 
 ## ensure directory
 RUN mkdir -p $ROOT_PROJECT/interface $ROOT_PROJECT/hiera $ROOT_PUPPET/brain $ROOT_PUPPET/test
@@ -24,7 +24,7 @@ COPY puppet/environment/$ENVIRONMENT/modules/webserver $ROOT_PUPPET/code/modules
 ##
 ## provision with puppet: either build a web, or api webserver image.
 ##
-##     docker build -f webserver.dockerfile -t jeff1evesque/ml-webserver:0.7 .
+##     docker build -f webserver.dockerfile -t jeff1evesque/ml-webserver:0.8 .
 ##
 RUN apt-get update && $PUPPET apply -e "class { webserver: \
     run      => false, \
@@ -34,8 +34,8 @@ RUN apt-get update && $PUPPET apply -e "class { webserver: \
 ##
 ## executed everytime container starts
 ##
-##     docker run --hostname webserver-api --name webserver-api -d jeff1evesque/ml-webserver:0.7 api 0.0.0.0 6001 6
-##     docker run --hostname webserver-web --name webserver-web -d jeff1evesque/ml-webserver:0.7 web 0.0.0.0 5001 6
+##     docker run --hostname webserver-api --name webserver-api -d jeff1evesque/ml-webserver:0.8 api 0.0.0.0 6001 6
+##     docker run --hostname webserver-web --name webserver-web -d jeff1evesque/ml-webserver:0.8 web 0.0.0.0 5001 6
 ##     docker run\
 ##         --name webserver\
 ##         --net=app_nw\
@@ -47,7 +47,7 @@ RUN apt-get update && $PUPPET apply -e "class { webserver: \
 ##         -v "${PROJECT_ROOT}/hiera:/var/machine-learning/hiera"\
 ##         -v "${PROJECT_ROOT}/brain:/var/machine-learning/brain"\
 ##         -v "${PROJECT_ROOT}/test:/var/machine-learning/test"\
-##         -d jeff1evesque/ml-webserver:0.7\
+##         -d jeff1evesque/ml-webserver:0.8\
 ##         test | sudo tee pytest.log
 ##
 WORKDIR $ROOT_PROJECT
diff --git a/hiera/database.yaml b/hiera/database.yaml
index b05179c46..a6ec75ad2 100644
--- a/hiera/database.yaml
+++ b/hiera/database.yaml
@@ -28,8 +28,8 @@ database:
         username: 'authenticated'
         password: 'password'
         keyserver: 'hkp://keyserver.ubuntu.com:80'
-        mongodb_key: '0C49F3730359A14518585931BC711F9BA15703C6'
-        source_list: 'deb [ arch=amd64 ] http://repo.mongodb.org/apt/ubuntu trusty/mongodb-org/3.4 multiverse'
+        mongodb_key: '9DA31620334BD75D9DCB49F368818C72E52529D4'
+        source_list: 'deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/4.0 multiverse'
 
         storage:
             dbPath:
diff --git a/hiera/packages.yaml b/hiera/packages.yaml
index d67a2f9c0..da79dc6ad 100644
--- a/hiera/packages.yaml
+++ b/hiera/packages.yaml
@@ -9,19 +9,24 @@ system:
     packages:
         apt:
             general:
-                inotify-tools: '3.14-1ubuntu1'
-                libssl-dev: '1.0.1f-1ubuntu2.2*'
-                openssl: '1.0.1f-1ubuntu2.2*'
-                python-dev: '2.7.5-5ubuntu3'
+                apt-transport-https: '1.2.*'
+                inotify-tools: '3.14-1ubuntu*'
+                libssl-dev: '1.0.2g-1ubuntu*'
+                openssl: '1.0.2g-1ubuntu*'
+                python3: '3.5*'
+                python-dev: '2.7*'
+                python3-pip: '8.1.1-2ubuntu*'
 
-        pip:
+        pip3:
             general:
-                flask-script: '2.0.5'
-                flask-jwt-extended: '3.3.4'
-                voluptuous: '0.10.5'
+                flask-script: '2.0.6'
+                flask-jwt-extended: '3.13.1'
+                voluptuous: '0.11.5'
                 pytest-flask: '0.10.0'
-                six: '1.5.2'
-                xmltodict: '0.10.1'
-                scrypt: '0.8.0'
-                pymongo: '3.4.0'
+                six: '1.11.0'
+                xmltodict: '0.11.0'
+                scrypt: '0.8.6'
+                pymongo: '3.7.1'
                 mlxtend: '0.13.0'
+                requests: '2.9.1'
+                flask: '1.0.2'
diff --git a/hiera/reverse-proxy/nginx-api.yaml b/hiera/reverse-proxy/nginx-api.yaml
index d31238255..d3ebc0f85 100644
--- a/hiera/reverse-proxy/nginx-api.yaml
+++ b/hiera/reverse-proxy/nginx-api.yaml
@@ -9,7 +9,6 @@
 reverse_proxy:
     type: 'api'
     vhost: 'machine-learning-api.com'
-    host_port: 9090
     listen_port: 6000
     proxy: 'api-reverse-proxy'
     members:
diff --git a/hiera/reverse-proxy/nginx-web.yaml b/hiera/reverse-proxy/nginx-web.yaml
index ccb832da2..c3b21f3d0 100644
--- a/hiera/reverse-proxy/nginx-web.yaml
+++ b/hiera/reverse-proxy/nginx-web.yaml
@@ -9,7 +9,6 @@
 reverse_proxy:
     type: 'web'
     vhost: 'machine-learning.com'
-    host_port: 8080
     listen_port: 5000
     proxy: 'web-reverse-proxy'
     members:
diff --git a/install_rancher b/install_rancher
index ca884fcd5..5ccd42135 100644
--- a/install_rancher
+++ b/install_rancher
@@ -10,9 +10,9 @@
 ##     - https://github.com/rancher/rancher/releases/tag/v1.6.18
 ##
 CWD=$(pwd)
-RANCHER_CLI_VERSION='v0.6.9'
-RANCHER_AGENT_VERSION='v1.2.10'
-RANCHER_SERVER_VERSION='v1.6.18'
+RANCHER_CLI_VERSION='v0.6.11'
+RANCHER_AGENT_VERSION='v1.2.11'
+RANCHER_SERVER_VERSION='v1.6.22'
 RANCHER_REPO='https://github.com/rancher/cli'
 BOOT2DOCKER_REPO='https://github.com/boot2docker/boot2docker'
 OPERATING_SYSTEM=$(uname -s)
diff --git a/puppet/environment/docker/Puppetfile b/puppet/environment/docker/Puppetfile
index 0b394c310..5ce63b27e 100644
--- a/puppet/environment/docker/Puppetfile
+++ b/puppet/environment/docker/Puppetfile
@@ -4,33 +4,28 @@
 
 mod 'stdlib',
   :git => 'https://github.com/puppetlabs/puppetlabs-stdlib.git',
-  :ref => '4.25.1'
+  :ref => '5.1.0'
 
 mod 'apt',
   :git => 'https://github.com/puppetlabs/puppetlabs-apt.git',
-  :ref => '4.5.1'
+  :ref => '6.1.1'
 
 mod 'mysql',
   :git => 'https://github.com/puppetlabs/puppetlabs-mysql.git',
-  :ref => '3.4.0'
+  :ref => '6.2.0'
 
 mod 'sys',
   :git => 'https://github.com/counsyl/puppet-sys.git',
-  :ref => '0.9.18'
-
-## includes pip, devel, flask, requests, pipx (enhanced pip).
-mod 'python',
-  :git => 'https://github.com/counsyl/puppet-python.git',
-  :ref => '0.9.9'
+  :ref => '0.9.23'
 
 mod 'timezone',
   :git => 'https://github.com/BashtonLtd/puppet-timezone.git',
-  :ref => '2.0.0'
+  :ref => '2.0.1'
 
 mod 'concat',
   :git => 'https://github.com/puppetlabs/puppetlabs-concat.git',
-  :ref => '4.2.1'
+  :ref => '5.1.0'
 
 mod 'nginx',
   :git => 'https://github.com/voxpupuli/puppet-nginx.git',
-  :ref => 'v0.11.0'
\ No newline at end of file
+  :ref => 'v0.14.0'
diff --git a/puppet/environment/docker/modules/mariadb/manifests/client.pp b/puppet/environment/docker/modules/mariadb/manifests/client.pp
deleted file mode 100644
index f8a6fd517..000000000
--- a/puppet/environment/docker/modules/mariadb/manifests/client.pp
+++ /dev/null
@@ -1,8 +0,0 @@
-###
-### client.pp, mysql::client: install, and configure mariadb-client.
-###
-class mariadb::client {
-    class { '::mysql::client':
-        package_name => 'mariadb-client',
-    }
-}
\ No newline at end of file
diff --git a/puppet/environment/docker/modules/mariadb/manifests/dependency.pp b/puppet/environment/docker/modules/mariadb/manifests/dependency.pp
index 912ed1d8e..91f8f182c 100644
--- a/puppet/environment/docker/modules/mariadb/manifests/dependency.pp
+++ b/puppet/environment/docker/modules/mariadb/manifests/dependency.pp
@@ -2,8 +2,7 @@
 ### dependency.pp, ensure directories.
 ###
 class mariadb::dependency {
-    ## python dependencies
-    contain python
+    contain system::packages
 
     ## local variables
     $root_dir       = $::mariadb::root_dir
@@ -13,15 +12,15 @@
     if ($redis_version and $redis_version != '*') {
         package { 'pyyaml':
             ensure      => $pyyaml_version,
-            provider    => 'pip',
-            require     => Class['python'],
+            provider    => 'pip3',
+            require     => Class['system::packages'],
         }
     }
     else {
         package { 'pyyaml':
             ensure      => 'installed',
-            provider    => 'pip',
-            require     => Class['python'],
+            provider    => 'pip3',
+            require     => Class['system::packages'],
         }
     }
 
diff --git a/puppet/environment/docker/modules/mariadb/manifests/init.pp b/puppet/environment/docker/modules/mariadb/manifests/init.pp
index 23c811945..9d9902097 100644
--- a/puppet/environment/docker/modules/mariadb/manifests/init.pp
+++ b/puppet/environment/docker/modules/mariadb/manifests/init.pp
@@ -22,7 +22,6 @@
 ) inherits ::mariadb::params {
     class { 'mariadb::dependency': } ->
     class { 'mariadb::server': } ->
-    class { 'mariadb::client': } ->
     class { 'mariadb::bindings': } ->
     Class['mariadb']
 }
diff --git a/puppet/environment/docker/modules/mariadb/manifests/server.pp b/puppet/environment/docker/modules/mariadb/manifests/server.pp
index f9eb48a6d..d41f619d6 100644
--- a/puppet/environment/docker/modules/mariadb/manifests/server.pp
+++ b/puppet/environment/docker/modules/mariadb/manifests/server.pp
@@ -22,6 +22,7 @@
     ##
     class { '::mysql::server':
         package_name    => 'mariadb-server',
+        service_name    => 'mysql',
         root_password   => $root_password,
         users         => {
             "${db_user}@${db_host}"     => {
diff --git a/puppet/environment/docker/modules/mongodb/manifests/install.pp b/puppet/environment/docker/modules/mongodb/manifests/install.pp
index 7f55f5087..ec2cb6d0f 100644
--- a/puppet/environment/docker/modules/mongodb/manifests/install.pp
+++ b/puppet/environment/docker/modules/mongodb/manifests/install.pp
@@ -7,7 +7,7 @@
     $mongodb_key         = $::mongodb::mongodb_key
     $mongodb_source_list = $::mongodb::mongodb_source_list
 
-    ## https://docs.mongodb.com/v3.4/tutorial/install-mongodb-on-ubuntu/
+    ## https://docs.mongodb.com/v4.0/tutorial/install-mongodb-on-ubuntu/
     exec { 'apt-key-puppetlabs':
         command => "apt-key adv --keyserver ${keyserver} --recv ${mongodb_key}",
         unless  => "apt-key list | grep ${mongodb_key}",
@@ -16,7 +16,7 @@
     }
 
     file { 'mongodb-list-file':
-        path    => '/etc/apt/sources.list.d/mongodb-org-3.4.list',
+        path    => '/etc/apt/sources.list.d/mongodb-org-4.0.list',
         content => $mongodb_source_list,
         require => Exec['apt-key-puppetlabs'],
         notify  => Exec['apt-get-update'],
@@ -24,7 +24,7 @@
 
     exec { 'apt-get-update':
         command     => 'apt-get update',
-        path        => '/usr/bin',
+        path        => ['/usr/bin', '/bin'],
         before      => Package['mongodb-org-server'],
         refreshonly => true,
     }
diff --git a/puppet/environment/docker/modules/mongodb/manifests/params.pp b/puppet/environment/docker/modules/mongodb/manifests/params.pp
index 0275ccb83..4656380e8 100644
--- a/puppet/environment/docker/modules/mongodb/manifests/params.pp
+++ b/puppet/environment/docker/modules/mongodb/manifests/params.pp
@@ -40,8 +40,8 @@
         $bindIp              = '127.0.0.1'
         $pidfilepath         = '/var/run/mongod.pid'
         $keyserver           = 'hkp://keyserver.ubuntu.com:80'
-        $mongodb_key         = '0C49F3730359A14518585931BC711F9BA15703C6'
-        $mongodb_source_list = 'deb [ arch=amd64 ] http://repo.mongodb.org/apt/ubuntu trusty/mongodb-org/3.4 multiverse'
+        $mongodb_key         = '9DA31620334BD75D9DCB49F368818C72E52529D4'
+        $mongodb_source_list = 'deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/4.0 multiverse'
         $authorization       = 'enabled'
         $hostname            = 'mongodb'
         $username            = 'authenticated'
diff --git a/puppet/environment/docker/modules/reverse_proxy/manifests/init.pp b/puppet/environment/docker/modules/reverse_proxy/manifests/init.pp
index d5b80dd8a..103d8033c 100644
--- a/puppet/environment/docker/modules/reverse_proxy/manifests/init.pp
+++ b/puppet/environment/docker/modules/reverse_proxy/manifests/init.pp
@@ -10,7 +10,6 @@
     $run            = $::reverse_proxy::params::run,
     $type           = $::reverse_proxy::params::type,
     $vhost          = $::reverse_proxy::params::vhost,
-    $host_port      = $::reverse_proxy::params::host_port,
     $listen_port    = $::reverse_proxy::params::listen_port,
     $members        = $::reverse_proxy::params::members,
     $proxy          = $::reverse_proxy::params::proxy,
diff --git a/puppet/environment/docker/modules/reverse_proxy/manifests/params.pp b/puppet/environment/docker/modules/reverse_proxy/manifests/params.pp
index 6ec11318b..049e43448 100644
--- a/puppet/environment/docker/modules/reverse_proxy/manifests/params.pp
+++ b/puppet/environment/docker/modules/reverse_proxy/manifests/params.pp
@@ -12,7 +12,6 @@
         $yaml           = true
         $type           = $hiera['type']
         $vhost          = $hiera['vhost']
-        $host_port      = $hiera['host_port']
         $listen_port    = $hiera['listen_port']
         $members        = $hiera['members']
         $proxy          = $hiera['proxy']
diff --git a/puppet/environment/docker/modules/sklearn/manifests/install.pp b/puppet/environment/docker/modules/sklearn/manifests/install.pp
index a7fcc78d4..0af4d56c8 100644
--- a/puppet/environment/docker/modules/sklearn/manifests/install.pp
+++ b/puppet/environment/docker/modules/sklearn/manifests/install.pp
@@ -2,7 +2,7 @@
 ### install.pp, install sklearn.
 ###
 class sklearn::install {
-    include python
+    include system::packages
 
     ## local variables
     $root_dir          = $::sklearn::root_dir
@@ -33,15 +33,15 @@
     if ($scikit_learn and $scikit_learn != '*') {
         package { "scikit_learn==${scikit_learn}":
             ensure   => 'installed',
-            provider => 'pip',
-            require  => Class['python'],
+            provider => 'pip3',
+            require  => Class['system::packages'],
         }
     }
     else {
         package { 'scikit_learn':
             ensure   => 'installed',
-            provider => 'pip',
-            require  => Class['python'],
+            provider => 'pip3',
+            require  => Class['system::packages'],
         }
     }
 }
\ No newline at end of file
diff --git a/puppet/environment/docker/modules/system/manifests/packages.pp b/puppet/environment/docker/modules/system/manifests/packages.pp
index 0836594d8..bbb68b265 100644
--- a/puppet/environment/docker/modules/system/manifests/packages.pp
+++ b/puppet/environment/docker/modules/system/manifests/packages.pp
@@ -3,7 +3,6 @@
 ###
 class system::packages {
     contain apt
-    contain python
 
     ## local variables
     $packages = $::system::packages
@@ -11,7 +10,7 @@
     ## iterate 'packages' hash
     if $packages {
         $packages.each |String $provider, $providers| {
-            if ($provider in ['apt', 'pip']) {
+            if ($provider in ['apt', 'pip3']) {
                 if has_key($providers, 'general') {
                     $providers['general'].each|String $package, String $version| {
                         package { $package:
@@ -19,7 +18,6 @@
                             provider => $provider,
                             require  => [
                                 Class['apt'],
-                                Class['python'],
                             ],
                         }
                     }
@@ -27,4 +25,4 @@
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/puppet/environment/docker/modules/webserver/manifests/init.pp b/puppet/environment/docker/modules/webserver/manifests/init.pp
index a8dbf7790..045dc33f5 100644
--- a/puppet/environment/docker/modules/webserver/manifests/init.pp
+++ b/puppet/environment/docker/modules/webserver/manifests/init.pp
@@ -8,20 +8,22 @@
 ###     - https://github.com/counsyl/puppet-python.git
 ###
 class webserver (
-    $run                = $::webserver::params::run,
-    $gunicorn_bind      = $::webserver::params::gunicorn_bind,
-    $gunicorn_port      = $::webserver::params::gunicorn_port,
-    $gunicorn_workers   = $::webserver::params::gunicorn_workers,
-    $gunicorn_type      = $::webserver::params::gunicorn_type,
-    $gunicorn_version   = $::webserver::params::gunicorn_version,
-    $root_dir           = $::webserver::params::root_dir,
-    $version            = $::webserver::params::version,
-    $flask_log_path     = $::webserver::params::flask_log_path,
-    $pyyaml_version     = $::webserver::params::pyyaml_version,
-    $redis_version      = $::webserver::params::redis_version,
-    $pytest_cov_version = $::webserver::params::pytest_cov_version,
-    $root_puppet        = $::webserver::params::root_puppet,
-    $platform           = $::webserver::params::platform,
+    $run                    = $::webserver::params::run,
+    $gunicorn_bind          = $::webserver::params::gunicorn_bind,
+    $gunicorn_port          = $::webserver::params::gunicorn_port,
+    $gunicorn_workers       = $::webserver::params::gunicorn_workers,
+    $gunicorn_type          = $::webserver::params::gunicorn_type,
+    $gunicorn_version       = $::webserver::params::gunicorn_version,
+    $root_dir               = $::webserver::params::root_dir,
+    $version                = $::webserver::params::version,
+    $flask_log_path         = $::webserver::params::flask_log_path,
+    $pyyaml_version         = $::webserver::params::pyyaml_version,
+    $redis_version          = $::webserver::params::redis_version,
+    $libmysqlclient_version = $::webserver::params::libmysqlclient_version,
+    $mysqlclient_version    = $::webserver::params::mysqlclient_version,
+    $pytest_cov_version     = $::webserver::params::pytest_cov_version,
+    $root_puppet            = $::webserver::params::root_puppet,
+    $platform               = $::webserver::params::platform,
 ) inherits ::webserver::params {
     class { 'webserver::install': } ->
     class { 'webserver::config': } ~>
diff --git a/puppet/environment/docker/modules/webserver/manifests/install.pp b/puppet/environment/docker/modules/webserver/manifests/install.pp
index 091ce1016..282ebce48 100644
--- a/puppet/environment/docker/modules/webserver/manifests/install.pp
+++ b/puppet/environment/docker/modules/webserver/manifests/install.pp
@@ -3,44 +3,55 @@
 ###
 class webserver::install {
     ## python dependencies
-    include python
-    include python::flask
-    include python::requests
+    include system::packages
 
     ## local variables
-    $pyyaml_version     = $::webserver::pyyaml_version
-    $redis_version      = $::webserver::redis_version
-    $pytest_cov_version = $::webserver::pytest_cov_version
-    $jest_cli_version   = $::webserver::jest_cli_version
-    $gunicorn_version   = $::webserver::version
-    $platform           = $::webserver::platform
+    $pyyaml_version         = $::webserver::pyyaml_version
+    $redis_version          = $::webserver::redis_version
+    $libmysqlclient_version = $::webserver::libmysqlclient_version
+    $mysqlclient_version    = $::webserver::mysqlclient_version
+    $pytest_cov_version     = $::webserver::pytest_cov_version
+    $jest_cli_version       = $::webserver::jest_cli_version
+    $gunicorn_version       = $::webserver::version
+    $platform               = $::webserver::platform
 
     ## development packages
     if ($platform == 'development') {
         package { 'pytest-cov':
-            ensure      => $pytest_cov_version,
-            provider    => 'pip',
-            require     => Class['python'],
+            ensure          => $pytest_cov_version,
+            provider        => 'pip3',
+            require         => Class['system::packages'],
         }
     }
 
     ## pyyaml
     package { 'pyyaml':
-        ensure          => $pyyaml_version,
-        provider        => 'pip',
-        require         => Class['python'],
+        ensure              => $pyyaml_version,
+        provider            => 'pip3',
+        require             => Class['system::packages'],
     }
 
     ## redis client
     package { 'redis':
-        ensure          => $redis_version,
-        provider        => 'pip',
-        require         => Class['python'],
+        ensure              => $redis_version,
+        provider            => 'pip3',
+        require             => Class['system::packages'],
     }
 
-    ## mariadb client
-    class { '::mysql::client':
-        package_name    => 'mariadb-client',
+    ##
+    ## mariadb client: workaround for python3x. By default 'MySQLdb' only
+    ##     supported on python2x.
+    ##
+    ##     - https://raspberrypi.stackexchange.com/a/78217
+    ##
+    package { 'libmysqlclient-dev':
+        ensure              => $libmysqlclient_version,
+        require             => Class['system::packages'],
+    }
+    package { 'mysqlclient':
+        ensure              => $mysqlclient_version,
+        provider            => 'pip3',
+        require             => Class['system::packages'],
     }
 
     ## mariadb bindings
@@ -50,7 +61,8 @@
 
     ## install gunicorn
     package { 'gunicorn':
-        ensure      => $gunicorn_version,
-        provider    => 'pip',
+        ensure          => $gunicorn_version,
+        provider        => 'pip3',
+        require         => Class['system::packages'],
     }
 }
diff --git a/puppet/environment/docker/modules/webserver/manifests/params.pp b/puppet/environment/docker/modules/webserver/manifests/params.pp
index e48feb8ce..b46eb41f1 100644
--- a/puppet/environment/docker/modules/webserver/manifests/params.pp
+++ b/puppet/environment/docker/modules/webserver/manifests/params.pp
@@ -2,31 +2,33 @@
 ### params.pp: default class parameters.
 ###
 class webserver::params {
-    $hiera                 = lookup( { 'name' => 'webserver', 'default_value' => false } )
-    $run                   = true
-    $pyyaml_version        = 'installed'
-    $redis_version         = 'installed'
-    $pytest_cov_version    = 'installed'
-    $jest_cli_version      = 'installed'
-    $gunicorn_version      = 'installed'
-    $root_puppet           = '/etc/puppetlabs'
-    $platform              = 'production'
+    $hiera                  = lookup( { 'name' => 'webserver', 'default_value' => false } )
+    $run                    = true
+    $pyyaml_version         = 'installed'
+    $redis_version          = 'installed'
+    $libmysqlclient_version = 'installed'
+    $mysqlclient_version    = 'installed'
+    $pytest_cov_version     = 'installed'
+    $jest_cli_version       = 'installed'
+    $gunicorn_version       = 'installed'
+    $root_puppet            = '/etc/puppetlabs'
+    $platform               = 'production'
 
     if $hiera {
-        $root_dir          = $hiera['root_dir']
-        $flask_log_path    = $hiera['flask']['log_path']
-        $gunicorn_bind     = $hiera['gunicorn']['bind']
-        $gunicorn_port     = $hiera['gunicorn']['port']
-        $gunicorn_workers  = $hiera['gunicorn']['workers']
-        $gunicorn_type     = $hiera['gunicorn']['type']
+        $root_dir           = $hiera['root_dir']
+        $flask_log_path     = $hiera['flask']['log_path']
+        $gunicorn_bind      = $hiera['gunicorn']['bind']
+        $gunicorn_port      = $hiera['gunicorn']['port']
+        $gunicorn_workers   = $hiera['gunicorn']['workers']
+        $gunicorn_type      = $hiera['gunicorn']['type']
     }
 
     else {
-        $root_dir          = '/var/machine-learning'
-        $flask_log_path    = '/var/log/webserver/flask.log'
-        $gunicorn_bind     = '0.0.0.0'
-        $gunicorn_port     = ''
-        $gunicorn_workers  = 6
-        $gunicorn_type     = 'web'
+        $root_dir           = '/var/machine-learning'
+        $flask_log_path     = '/var/log/webserver/flask.log'
+        $gunicorn_bind      = '0.0.0.0'
+        $gunicorn_port      = ''
+        $gunicorn_workers   = 6
+        $gunicorn_type      = 'web'
     }
 }
diff --git a/puppet/environment/docker/modules/webserver/templates/entrypoint.erb b/puppet/environment/docker/modules/webserver/templates/entrypoint.erb
index 319245e4f..09c94fd16 100644
--- a/puppet/environment/docker/modules/webserver/templates/entrypoint.erb
+++ b/puppet/environment/docker/modules/webserver/templates/entrypoint.erb
@@ -14,7 +14,7 @@ CONFDIR=<%= @root_puppet %>/puppet
 
 ## run application
 if [ "$GUNICORN_TYPE" = 'test' ]; then
-    python app.py test
+    python3 app.py test
 
 else
     gunicorn \
diff --git a/test/backend b/test/backend
index f8178d59c..505518726 100644
--- a/test/backend
+++ b/test/backend
@@ -25,12 +25,14 @@ fi
 ##   - stop all docker containers
 ##   - remove all docker containers
 ##   - remove all docker images
+##   - remove all docker dangling images
 ##   - remove all docker volumes
 ##   - delete all docker networks
 ##
 if [ "$RECYCLE" = 'true' ] && which docker >/dev/null 2>&1; then
     sudo docker ps -q | xargs -r docker kill
     sudo docker ps -a -q | xargs -r docker rm
+    sudo docker rmi $(docker images -q)
     sudo docker images -q -f dangling=true | xargs -r docker rmi
     sudo docker volume ls -qf dangling=true | xargs -r docker volume rm
     sudo docker network ls -q | xargs -r docker network rm
diff --git a/test/live_server/1_authentication/pytest_1_crypto.py b/test/live_server/1_authentication/pytest_1_crypto.py
index 8e470befc..44863e74b 100644
--- a/test/live_server/1_authentication/pytest_1_crypto.py
+++ b/test/live_server/1_authentication/pytest_1_crypto.py
@@ -15,7 +15,7 @@ def test_hashing():
         cryptopath = root + '/brain/converter/crypto.py'
         crypto = imp.load_source('crypto', cryptopath)
     except Exception as error:
-        print error
+        print(error)
 
     passwords = ['blue', 'red', 'green', 'yellow']
 
diff --git a/test/live_server/1_authentication/pytest_3_validate_password.py b/test/live_server/1_authentication/pytest_3_validate_password.py
index d1cdfacbb..a4767c9dd 100644
--- a/test/live_server/1_authentication/pytest_3_validate_password.py
+++ b/test/live_server/1_authentication/pytest_3_validate_password.py
@@ -17,7 +17,7 @@ def test_validate_password():
             validate_password = root + '/brain/validator/password.py'
             vp = imp.load_source('validate_password', validate_password)
         except yaml.YAMLError as error:
-            print error
+            print(error)
 
     passwords = [
         'abcdefghij123',  # just right
diff --git a/test/live_server/3_programmatic_interface/results/pytest_1_svm_prediction.py b/test/live_server/3_programmatic_interface/results/pytest_1_svm_prediction.py
index 4cd29507c..af2570632 100644
--- a/test/live_server/3_programmatic_interface/results/pytest_1_svm_prediction.py
+++ b/test/live_server/3_programmatic_interface/results/pytest_1_svm_prediction.py
@@ -97,13 +97,13 @@ def save_prediction():
     assert res.status_code == 200
 
     if res.json['status'] == 1:
-        print 'Unsuccessful storing the prediction result.'
+        print('Unsuccessful storing the prediction result.')
         assert False
     elif res.json['status'] == 2:
-        print 'Status was not valid.'
+        print('Status was not valid.')
         assert False
     elif res.json['status'] == 3:
-        print 'Improper request submitted.'
+        print('Improper request submitted.')
         assert False
     else:
         assert res.json['status'] == 0
@@ -134,10 +134,10 @@ def retrieve_prediction():
     assert res.status_code == 200
 
     if res.json['status'] == 1:
-        print 'Unsuccessful retrieval of specified prediction parameter.'
+        print('Unsuccessful retrieval of specified prediction parameter.')
         assert False
     elif res.json['status'] == 2:
-        print 'Improper request submitted.'
+        print('Improper request submitted.')
         assert False
     else:
         assert res.json['status'] == 0
@@ -188,10 +188,10 @@ def retrieve_prediction_titles():
     assert res.status_code == 200
 
     if res.json['status'] == 1:
-        print 'Unsuccessful retrieval of prediction titles.'
+        print('Unsuccessful retrieval of prediction titles.')
         assert False
     elif res.json['status'] == 2:
-        print 'Improper request submitted.'
+        print('Improper request submitted.')
         assert False
     else:
         assert res.json['status'] == 0
diff --git a/test/live_server/3_programmatic_interface/results/pytest_2_svr_prediction.py b/test/live_server/3_programmatic_interface/results/pytest_2_svr_prediction.py
index ef21cf669..1499d31c7 100644
--- a/test/live_server/3_programmatic_interface/results/pytest_2_svr_prediction.py
+++ b/test/live_server/3_programmatic_interface/results/pytest_2_svr_prediction.py
@@ -97,13 +97,13 @@ def save_prediction():
     assert res.status_code == 200
 
     if res.json['status'] == 1:
-        print 'Unsuccessful storing the prediction result.'
+        print('Unsuccessful storing the prediction result.')
         assert False
     elif res.json['status'] == 2:
-        print 'Status was not valid.'
+        print('Status was not valid.')
         assert False
     elif res.json['status'] == 3:
-        print 'Improper request submitted.'
+        print('Improper request submitted.')
         assert False
     else:
         assert res.json['status'] == 0
@@ -136,10 +136,10 @@ def retrieve_prediction():
     assert res.status_code == 200
 
     if res.json['status'] == 1:
-        print 'Unsuccessful retrieval of specified prediction parameter.'
+        print('Unsuccessful retrieval of specified prediction parameter.')
         assert False
     elif res.json['status'] == 2:
-        print 'Improper request submitted.'
+        print('Improper request submitted.')
         assert False
     else:
         assert res.json['status'] == 0
@@ -176,10 +176,10 @@ def retrieve_prediction_titles():
     assert res.status_code == 200
 
     if res.json['status'] == 1:
-        print 'Unsuccessful retrieval of prediction titles'
+        print('Unsuccessful retrieval of prediction titles')
         assert False
     elif res.json['status'] == 2:
-        print 'Improper request submitted.'
+        print('Improper request submitted.')
         assert False
     else:
         assert res.json['status'] == 0
diff --git a/test/live_server/3_programmatic_interface/results/pytest_3_all_prediction_titles.py b/test/live_server/3_programmatic_interface/results/pytest_3_all_prediction_titles.py
index 997a5dbb9..f9bb4c718 100644
--- a/test/live_server/3_programmatic_interface/results/pytest_3_all_prediction_titles.py
+++ b/test/live_server/3_programmatic_interface/results/pytest_3_all_prediction_titles.py
@@ -96,10 +96,10 @@ def retrieve_prediction_titles():
     assert res.status_code == 200
 
     if res.json['status'] == 1:
-        print 'Unsuccessful retrieval of prediction titles'
+        print('Unsuccessful retrieval of prediction titles')
         assert False
     elif res.json['status'] == 2:
-        print 'Improper request submitted.'
+        print('Improper request submitted.')
         assert False
     else:
         assert res.json['status'] == 0