jon-wei commented on a change in pull request #6126: New quickstart and tutorials URL: https://github.com/apache/incubator-druid/pull/6126#discussion_r209117132
########## File path: docs/content/tutorials/tutorial-batch-hadoop.md ########## @@ -0,0 +1,247 @@ +--- +layout: doc_page +--- + +# Tutorial: Load batch data using Hadoop + +This tutorial shows you how to load data files into Druid using a remote Hadoop cluster. + +For this tutorial, we'll assume that you've already completed the previous [batch ingestion tutorial](tutorial-batch.html). +using Druid's native batch ingestion system. + +## Install Docker + +This tutorial requires [Docker](https://docs.docker.com/install/) to be installed on the tutorial machine. + +Once the Docker install is complete, please proceed to the next steps in the tutorial. + +## Build the Hadoop docker image + +For this tutorial, we've provided a Dockerfile for a Hadoop 2.8.3 cluster, which we'll use to run the batch indexing task. + +This Dockerfile and related files are located at `quickstart/tutorial/hadoop/docker`. + +From the druid-${DRUIDVERSION} package root, run the following commands to build a Docker image named "druid-hadoop-demo" with version tag "2.8.3": + +``` +cd quickstart/tutorial/hadoop/docker +docker build -t druid-hadoop-demo:2.8.3 . +``` + +This will start building the Hadoop image. Once the image build is done, you should see the message `Successfully tagged druid-hadoop-demo:2.8.3` printed to the console. + +## Setup the Hadoop docker cluster + +### Create temporary shared directory + +We'll need a shared folder between the host and the Hadoop container for transferring some files. + +Let's create some folders under `/tmp`, we will use these later when starting the Hadoop container: + +``` +mkdir -p /tmp/shared +mkdir -p /tmp/shared/hadoop_xml +``` + +### Configure /etc/hosts + +On the host machine, add the following entry to `/etc/hosts`: + +``` +127.0.0.1 druid-hadoop-demo +``` + +### Start the Hadoop container + +Once the `/tmp/shared` folder has been created and the `etc/hosts` entry has been added, run the following command to start the Hadoop container. + +``` +docker run -it -h druid-hadoop-demo -p 50010:50010 -p 50020:50020 -p 50075:50075 -p 50090:50090 -p 8020:8020 -p 10020:10020 -p 19888:19888 -p 8030:8030 -p 8031:8031 -p 8032:8032 -p 8033:8033 -p 8040:8040 -p 8042:8042 -p 8088:8088 -p 8443:8443 -p 2049:2049 -p 9000:9000 -p 49707:49707 -p 2122:2122 -p 34455:34455 -v /tmp/shared:/shared druid-hadoop-demo:2.8.3 /etc/bootstrap.sh -bash +``` + +Once the container is started, your terminal will attach to a bash shell running inside the container: + +``` +Starting sshd: [ OK ] +18/07/26 17:27:15 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable +Starting namenodes on [druid-hadoop-demo] +druid-hadoop-demo: starting namenode, logging to /usr/local/hadoop/logs/hadoop-root-namenode-druid-hadoop-demo.out +localhost: starting datanode, logging to /usr/local/hadoop/logs/hadoop-root-datanode-druid-hadoop-demo.out +Starting secondary namenodes [0.0.0.0] +0.0.0.0: starting secondarynamenode, logging to /usr/local/hadoop/logs/hadoop-root-secondarynamenode-druid-hadoop-demo.out +18/07/26 17:27:31 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable +starting yarn daemons +starting resourcemanager, logging to /usr/local/hadoop/logs/yarn--resourcemanager-druid-hadoop-demo.out +localhost: starting nodemanager, logging to /usr/local/hadoop/logs/yarn-root-nodemanager-druid-hadoop-demo.out +starting historyserver, logging to /usr/local/hadoop/logs/mapred--historyserver-druid-hadoop-demo.out +bash-4.1# +``` + +The `Unable to load native-hadoop library for your platform... using builtin-java classes where applicable` warning messages can be safely ignored. + +### Copy input data to the Hadoop container + +From the druid-${DRUIDVERSION} package root on the host, copy the `quickstart/wikiticker-2015-09-12-sampled.json.gz` sample data to the shared folder: + +``` +cp quickstart/wikiticker-2015-09-12-sampled.json.gz /tmp/shared/wikiticker-2015-09-12-sampled.json.gz +``` + +### Setup HDFS directories + +In the Hadoop container's shell, run the following commands to setup the HDFS directories needed by this tutorial and copy the input data to HDFS. + +``` +cd /usr/local/hadoop/bin +./hadoop fs -mkdir /druid +./hadoop fs -mkdir /druid/segments +./hadoop fs -mkdir /quickstart +./hadoop fs -chmod 777 /druid +./hadoop fs -chmod 777 /druid/segments +./hadoop fs -chmod 777 /quickstart +./hadoop fs -chmod -R 777 /tmp +./hadoop fs -chmod -R 777 /user +./hadoop fs -put /shared/wikiticker-2015-09-12-sampled.json.gz /quickstart/wikiticker-2015-09-12-sampled.json.gz +``` + +If you encounter namenode errors when running this command, the Hadoop container may not be finished initializing. When this occurs, wait a couple of minutes and retry the commands. + +## Configure Druid to use Hadoop + +Some additional steps are needed to configure the Druid cluster for Hadoop batch indexing. + +### Copy Hadoop configuration to Druid classpath + +From the Hadoop container's shell, run the following command to copy the Hadoop .xml configuration files to the shared folder: + +``` +cp /usr/local/hadoop/etc/hadoop/*.xml /shared/hadoop_xml +``` + +From the host machine, run the following, where {PATH_TO_DRUID} is replaced by the path to the Druid package. + +``` +mkdir -p {PATH_TO_DRUID}/quickstart/tutorial/conf/druid/_common/hadoop-xml +cp /tmp/shared/hadoop_xml/*.xml {PATH_TO_DRUID}/quickstart/tutorial/conf/druid/_common/hadoop-xml/ +``` + +### Update Druid segment and log storage + +In your favorite text editor, open `quickstart/tutorial/conf/druid/_common/common.runtime.properties`, and make the following edits: + +#### Disable local deep storage and enable HDFS deep stroage + +``` +# +# Deep storage +# + +# For local disk (only viable in a cluster if this is a network mount): +#druid.storage.type=local +#druid.storage.storageDirectory=var/druid/segments + +# For HDFS: +druid.storage.type=hdfs +druid.storage.storageDirectory=/druid/segments +``` + + +#### Disable local log storage and enable HDFS log storage + +``` +# +# Indexing service logs +# + +# For local disk (only viable in a cluster if this is a network mount): +#druid.indexer.logs.type=file +#druid.indexer.logs.directory=var/druid/indexing-logs + +# For HDFS: +druid.indexer.logs.type=hdfs +druid.indexer.logs.directory=/druid/indexing-logs + +``` + +### Restart Druid cluster + +Once the Hadoop .xml files have been copied to the Druid cluster and the segment/log storage configuration has been updated to use HDFS, the Druid cluster needs to be restarted for the new configurations to take effect. 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