Updating the README.md file for Hue

hue/README.md

@@ -22,7 +22,7 @@ installed:
         --initialization-actions gs://goog-dataproc-initialization-actions-${REGION}/hue/hue.sh
     ```
 
-1.  Once the cluster has been created, Hue is configured to run on port `8888`
+2.  Once the cluster has been created, Hue is configured to run on port `8888`
     on the master node in a Dataproc cluster. To connect to the Hue web
     interface, you will need to create an SSH tunnel and use a SOCKS 5 Proxy
     with your web browser as described in the
@@ -37,3 +37,118 @@ installed:
     initialization action](../oozie/README.md) before this one in the
     --initialization-actions list argument to `gcloud dataproc
     clusters create`.
+
+****************************************************************************
+
+## Example: Hue \+ Hive (SQL UI) \- basic SQL queries
+
+1.  Create warehouse bucket:
+
+    ```
+    export WAREHOUSE_BUCKET=<BUCKET NAME>
+    gsutil mb -l ${REGION} gs://${WAREHOUSE_BUCKET}
+    ```
+
+2.  Prepare dataset: Copy the sample dataset to your warehouse bucket:  
+
+    ```
+    gsutil cp gs://hive-solution/part-00000.parquet \
+    gs://${WAREHOUSE_BUCKET}/datasets/transactions/part-00000.parquet
+    ```
+
+3.  Create Dataproc cluster using [hue.sh](https://github.com/GoogleCloudDataproc/initialization-actions/blob/master/hue/hue.sh) init script 
+
+    ```
+    export CLUSTER_NAME=<CLUSTER_NAME>
+    export REGION=<REGION>
+    export INIT_BUCKET=<INIT_BUCKET_NAME>
+    gcloud dataproc clusters create ${CLUSTER_NAME} \
+    --region ${REGION} \
+    --initialization-actions gs://${INIT_BUCKET}/hue.sh \
+    --properties "hive:hive.metastore.warehouse.dir=gs://${WAREHOUSE_BUCKET}/datasets"
+    ```
+
+4.  Configure Hue editor in the Dataproc cluster. SSH on master node and edit hue.ini as follows:  
+   1. Under \[beeswax\] section configure [Apache Hive connector](https://docs.gethue.com/administrator/configuration/connectors/\#apache-hive) by uncommenting hive\_server\_host and hive\_server\_port  
+   2. Under \[\[ interpreters \]\] section add following block  
+          ```
+          [[[Beeswax]]]
+          name=Hive
+          interface=hiveserver2
+          ```
+   3. Restart hue: \[[link to section](\#changes-made-to-hue.ini-are-not-effective-after-restart-using-systemctl)\]  
+   4. Exit master node
+
+5.  Connect to the Hue web interface: Create an SSH tunnel and use a SOCKS 5 Proxy with your web browser as described in the dataproc web interfaces documentation. In the opened web browser go to 'localhost:8888' and you should see the Hue UI.  
+6.  Hue UI: Create an external Hive table for the dataset: 
+
+    ```
+    CREATE EXTERNAL TABLE transactions
+    (SubmissionDate DATE, TransactionAmount DOUBLE, TransactionType STRING)
+    STORED AS PARQUET
+    LOCATION 'gs://${WAREHOUSE_BUCKET}/datasets/transactions';"
+    ```
+    ![External Hive table for the dataset](https://github.com/e55010104110/initialization-actions/blob/master/hue/create-hive-table.png)
+
+7.  Run the following simple HiveQL query to select the 10 transactions:
+
+    ```
+    SELECT *
+    	FROM transactions
+    	LIMIT 10;"
+    ```
+    ![HiveQL query to select the 10 transactions](https://github.com/e55010104110/initialization-actions/blob/master/hue/simple-hiveql.png)
+
+8.  Another query:
+
+    ```
+    SELECT TransactionType, COUNT(TransactionType) as Count
+        FROM transactions
+        WHERE SubmissionDate = '2017-08-22'
+        GROUP BY TransactionType;"
+    ```
+   ![Another query](https://github.com/e55010104110/initialization-actions/blob/master/hue/another-query.png)
+
+****************************************************************************
+
+## Common issues
+
+1.  ### Missing configurations for the distributed Hadoop services
+
+![Hue UI](https://github.com/e55010104110/initialization-actions/blob/master/hue/hue-ui.png)
+
+The hue.ini configuration file is configured to assume a single-node cluster with hostnames set to localhost and port numbers set to default values. For a distributed system, the different sections for each Hadoop service must be updated with the correct hostnames and ports for the servers on which the services are running. 
+
+The hue.sh script performs some generic updates to the hostnames, such as replacing all occurrences of localhost with the fully qualified domain name (FQDN), but additional configurations may be required based on the available services, as described in the documentation for [How to configure Hue for your Hadoop cluster.](https://gethue.com/how-to-configure-hue-in-your-hadoop-cluster/)
+
+2.  ### Changes made to hue.ini are not effective after restart using systemctl {#changes-made-to-hue.ini-are-not-effective-after-restart-using-systemctl}
+
+    `systemctl restart hue.service` leaves behind some orphaned processes and the following command can be used to perform a clean restart of Hue: `sudo /etc/init.d/hue force-stop && sudo /etc/init.d/hue start`
+
+3.  ### User \[hue\] not defined as proxyuser" when integrated with Oozie
+
+    This is caused by missing ProxyUser/impersonation configuration for the logged in user in Oozie.   
+    [Hue.sh](https://github.com/GoogleCloudDataproc/initialization-actions/blob/12792d9d40821e1fad202756e2532a1a8768fe54/hue/hue.sh\#L136) only adds the default user Hue as a ProxyUser, therefore all the other users must also be added. 
+
+1.  Identify the impacted user for example in the error message below it is the  doAs user \`hueuser\`:  *401 Client Error: Unauthorized for url: http://\<redacted\>:11000/oozie/v1/jobs?len=100\&doAs=hueuser\&filter=user%3Dhueadmin%3Bstartcreatedtime%3D-7d\&user.name=hue\&offset=1\&timezone=America%2FLos\_Angeles\&jobtype=wf {"errorMessage":"User \[hue\] not defined as proxyuser","httpStatusCode":401} (error 401\)*  
+
+2.  Add the following properties to oozie-site as follows replacing the \#USER\# with the impacted user in step 1 above. 
+
+    ```
+    <property>
+        <name>oozie.service.ProxyUserService.proxyuser.\#USER\#.hosts\</name>  
+        <value>*</value>  
+    </property>  
+    <property>  
+        <name>oozie.service.ProxyUserService.proxyuser.\#USER\#.groups\</name\> 
+        <value>*</value>  
+    </property>
+    ```
+
+3.  Restart Oozie  
+   1.   Find the process number for the `org.apache.oozie.server.EmbeddedOozieServer  ps \-ef | grep oozie`  
+   2.   Kill the process by PID sudo kill \-9 \<PID\>  
+   3.   Confirm that the process is not running:  `ps \-ef | grep oozie`  
+   4.   Restart Oozie service `sudo systemctl restart oozie.service`
+
+****************************************************************************