diff --git a/nixos/big_data.nix b/nixos/big_data.nix
index 3efcad5..7566112 100644
--- a/nixos/big_data.nix
+++ b/nixos/big_data.nix
@@ -1,11 +1,16 @@
 { config, lib, pkgs, ... }:
 let
   keytab_path = /etc/hadoop.keytab;
+  pysparkPackageSelector = p: with p; [ numpy pyspark ];
+  pysparkEnv = pkgs.python3.withPackages pysparkPackageSelector;
   hadoopConf = import <nixos/nixos/modules/services/cluster/hadoop/conf.nix> {
     inherit pkgs lib;
     cfg = config.services.hadoop;
   };
   hadoopConfDir = "${hadoopConf}/";
+  spark = pkgs.spark.override {
+    extraPythonPackages = pysparkPackageSelector pkgs.python3.pkgs;
+  };
   sparkConfDir = pkgs.stdenv.mkDerivation {
     name = "spark-config";
     dontUnpack = true;
@@ -31,7 +36,8 @@ let
       export JAVA_HOME="${pkgs.jdk8}"
       export SPARK_HOME="${pkgs.spark}/lib/${pkgs.spark.untarDir}"
       export SPARK_DIST_CLASSPATH=$(${pkgs.hadoop}/bin/hadoop classpath)
-      export PYSPARK_PYTHON="${pkgs.python3Packages.python}/bin/${pkgs.python3Packages.python.executable}"
+      export PYSPARK_PYTHON="${pysparkEnv.outPath}/bin/${pysparkEnv.executable}:"
+      export PYSPARK_DRIVER_PYTHON="${pysparkEnv.outPath}/bin/${pysparkEnv.executable}:"
       export PYTHONPATH="\$PYTHONPATH:$PYTHONPATH"
       export HADOOP_CONF_DIR="${hadoopConfDir}"
       export SPARKR_R_SHELL="${pkgs.R}/bin/R"
@@ -42,8 +48,8 @@ let
       spark.eventLog.enabled          		true
       spark.eventLog.dir              		hdfs://localhost:/logs/spark
       spark.history.fs.logDirectory   		hdfs://localhost:/logs/spark
-      spark.yarn.keytab                   ${keytab_path}
-      spark.yarn.principal								spark/my.engine@MY.ENGINE
+      # spark.yarn.keytab                   ${keytab_path}
+      # spark.yarn.principal								spark/my.engine@MY.ENGINE
       STOP
     '';
   };
@@ -63,19 +69,12 @@ in
 
   services = {
     spark = {
-      master = {
-        enable = true;
-        restartIfChanged = true;
-      };
-      worker = {
-        enable = true;
-        restartIfChanged = true;
-      };
+      package = spark;
+      master = { enable = true; restartIfChanged = true; };
+      worker = { enable = true; restartIfChanged = true; };
       confDir = sparkConfDir;
     };
 
-
-
     hadoop = {
       coreSite = {
         "fs.defaultFS" = "hdfs://my.engine:8020";
@@ -188,11 +187,7 @@ in
       enable = true;
       realms."MY.ENGINE".acl = [
         { principal = "*/admin"; access = "all"; }
-        { principal = "admin"; access = "all"; }
-        { principal = "*/localhost"; access = "all"; }
         { principal = "*/my.engine"; access = "all"; }
-        { principal = "nn/my.engine"; access = "all"; }
-        { principal = "hdfs"; access = "all"; }
       ];
     };
   };