update manual installation

chapter_5/installation/manual_installation.rst

@@ -159,7 +159,7 @@ To enable the Security Manager a system administrator have to add some options t
 .. code-block:: bash
 	:linenos:
 
-      export JAVA_OPTS="$JAVA_OPTS -Djava.security.manager -Djava.security.policy=$CATALINA_HOME/conf/knowage-default.policy -Dsymmetric_encryption_key=<generic_random_string>"
+        export JAVA_OPTS="$JAVA_OPTS -Djava.security.manager -Djava.security.policy=$CATALINA_HOME/conf/knowage-default.policy -Dsymmetric_encryption_key=<generic_random_string>"
 
 The symmetric_encryption_key is required to encrypt/decrypt the JDBC data source password. Its value must be a generic ASCII string with at least one character.
 
@@ -169,10 +169,14 @@ The symmetric_encryption_key is required to encrypt/decrypt the JDBC data source
 .. code-block:: bash
 	:linenos:
 
-      set JAVA_OPTS= %JAVA_OPTS% -Djava.security.manager -Djava.security.policy=%CATALINA_HOME%\conf\knowage-default.policy -Dsymmetric_encryption_key=<generic_ASCII_string>
+        set JAVA_OPTS= %JAVA_OPTS% -Djava.security.manager -Djava.security.policy=%CATALINA_HOME%\conf\knowage-default.policy -Dsymmetric_encryption_key=<generic_ASCII_string>
 
 The symmetric_encryption_key is required to encrypt/decrypt the JDBC data source password. Its value must be a generic ASCII string with at least one character.
 
+.. warning::
+
+  If you are using Oracle provided Java, this configuration may lead to the error *"Illegal key size or default parameters"*. This is a problem with limited Java security policies. See https://docs.oracle.com/javase/8/docs/technotes/guides/security/crypto/CryptoSpec.html#AppC for more information.
+
 Installation of Chromium Cockpit Export script
 -----------------------------------------------
 .. important::
@@ -194,6 +198,8 @@ Configuring environment for Data Preparation
 
 User should have Apache Livy and Apache Spark installed.
 
+This feature is tested on Apache Livy 0.71 and Apache Spark 2.4.8 with Scala 2_11 version.
+
 Please refer to https://livy.apache.org/ for more details:
 
 To run the Livy server, you will also need an Apache Spark installation.
@@ -202,8 +208,6 @@ Livy requires at least Spark 1.6 and supports both Scala 2.10 and 2.11 builds of
 
 export SPARK_HOME=/usr/lib/spark
 
-export HADOOP_CONF_DIR=/etc/hadoop/conf
-
 Then start the server with:
 
 ./bin/livy-server start
@@ -215,33 +219,34 @@ Please check Livy and Spark official documentation for more info.
 After that it is mandatory to set this variable on Tomcat Server: **KNOWAGE_RESOURCE_PATH**
 This variable should point to the Tomcat server's resource folder.
 
-Our advice, if you are on Linux environment, is to create a service for Tomcat Server and then let the variable setting available for the system, for example:
-KNOWAGE_RESOURCE_PATH = /home/knowage/knowage8_1/apache-tomcat-9/resources
+Our advice, if you are on Linux environment, is to create a service for Tomcat Server and then let the variable setting available for the system, for example: KNOWAGE_RESOURCE_PATH = /home/knowage/knowage8_1/apache-tomcat-9/resources
+
+After that, you should fill this property inside Knowage Configuration:  **KNOWAGE.DATAPREP.LIVY_URL** with the right url of Livy server.
+
+You will also need to configure a datasource as "Used for data preparation", it means that the selected datasource will be used for saving prepared dataset data.
+
+Selecting a **DATA PREPARATION DATASOURCE**:
+
+It is really important to set a datasource for the prepared dataset ingestion output.
+This one will be the location of the result prepared data.
+You can do that checking the "Use for data preparation" checkbox using an administration role for Knowage.
+
+.. figure:: media/image37.png
 
-After that, you should fill this property inside Knowage Configuration:  **KNOWAGE.DATAPREP.LIVY_URL**
-with the right url of Livy server.
+    Datasource management section.
 
 In order to allow Spark transformations working, you should provide those libraries on Spark  /jars  installation folder:
 
 - json-20210307.jar
+
 - livy-api-0.7.1-incubating.jar
+
 - livy-client-http-0.7.1-incubating.jar
+
 - spark-avro_2.11-2.4.8.jar
 
 And:
 
 - knowage-spark-[**CURRENT VERSION OF KNOWAGE**].jar
 
 This library can be found inside knowage deployed projects jars folder.
-
-You will also need to configure a datasource as "Used for data preparation", it means that the selected datasource will be used for saving prepared dataset data.
-
-Selecting a **DATA PREPARATION DATASOURCE**:
-
-It is really important to set a datasource for the prepared dataset ingestion output.
-This one will be the location of the result prepared data.
-You can do that checking the "Use for data preparation" checkbox using an administration role for Knowage.
-
-.. figure:: media/image37.png
-
-    Datasource management section.