http://git-wip-us.apache.org/repos/asf/hbase/blob/cb77a925/src/main/asciidoc/_chapters/external_apis.adoc ---------------------------------------------------------------------- diff --git a/src/main/asciidoc/_chapters/external_apis.adoc b/src/main/asciidoc/_chapters/external_apis.adoc new file mode 100644 index 0000000..dfc64e3 --- /dev/null +++ b/src/main/asciidoc/_chapters/external_apis.adoc @@ -0,0 +1,66 @@ +//// +/** + * + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +//// + +[[external_apis]] += Apache HBase External APIs +:doctype: book +:numbered: +:toc: left +:icons: font +:experimental: + +This chapter will cover access to Apache HBase either through non-Java languages, or through custom protocols. +For information on using the native HBase APIs, refer to link:http://hbase.apache.org/apidocs/index.html[User API Reference] and the new <<hbase_apis,hbase apis>> chapter. + +[[nonjava.jvm]] +== Non-Java Languages Talking to the JVM + +Currently the documentation on this topic in the link:http://wiki.apache.org/hadoop/Hbase[Apache HBase Wiki]. +See also the link:http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/thrift/package-summary.html#package_description[Thrift API Javadoc]. + +== REST + +Currently most of the documentation on REST exists in the link:http://wiki.apache.org/hadoop/Hbase/Stargate[Apache HBase Wiki on REST] (The REST gateway used to be called 'Stargate'). There are also a nice set of blogs on link:http://blog.cloudera.com/blog/2013/03/how-to-use-the-apache-hbase-rest-interface-part-1/[How-to: Use the Apache HBase REST Interface] by Jesse Anderson. + +To run your REST server under SSL, set hbase.rest.ssl.enabled to true and also set the following configs when you launch the REST server:(See example commands in <<jmx_config,JMX config>>) +[source] +---- + +hbase.rest.ssl.keystore.store +hbase.rest.ssl.keystore.password +hbase.rest.ssl.keystore.keypassword +---- + +HBase ships a simple REST client, see link:http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/rest/client/package-summary.html[REST client] package for details. +To enable SSL support for it, please also import your certificate into local java cacerts keystore: +---- +keytool -import -trustcacerts -file /home/user/restserver.cert -keystore $JAVA_HOME/jre/lib/security/cacerts +---- + +== Thrift + +Documentation about Thrift has moved to <<thrift,thrift>>. + +[[c]] +== C/C++ Apache HBase Client + +FB's Chip Turner wrote a pure C/C++ client. + link:https://github.com/facebook/native-cpp-hbase-client[Check it out].
http://git-wip-us.apache.org/repos/asf/hbase/blob/cb77a925/src/main/asciidoc/_chapters/faq.adoc ---------------------------------------------------------------------- diff --git a/src/main/asciidoc/_chapters/faq.adoc b/src/main/asciidoc/_chapters/faq.adoc new file mode 100644 index 0000000..22e4ad3 --- /dev/null +++ b/src/main/asciidoc/_chapters/faq.adoc @@ -0,0 +1,141 @@ +//// +/** + * + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +//// + +[appendix] +[[faq]] +== FAQ +:doctype: book +:numbered: +:toc: left +:icons: font +:experimental: + +=== General +When should I use HBase?:: + See <<arch.overview>> in the Architecture chapter. + +Are there other HBase FAQs?:: + See the FAQ that is up on the wiki, link:http://wiki.apache.org/hadoop/Hbase/FAQ[HBase Wiki FAQ]. + +Does HBase support SQL?:: + Not really. SQL-ish support for HBase via link:http://hive.apache.org/[Hive] is in development, however Hive is based on MapReduce which is not generally suitable for low-latency requests. See the <<datamodel>> section for examples on the HBase client. + +How can I find examples of NoSQL/HBase?:: + See the link to the BigTable paper in <<other.info>>, as well as the other papers. + +What is the history of HBase?:: + See <<hbase.history,hbase.history>>. + +=== Upgrading +How do I upgrade Maven-managed projects from HBase 0.94 to HBase 0.96+?:: + In HBase 0.96, the project moved to a modular structure. Adjust your project's dependencies to rely upon the `hbase-client` module or another module as appropriate, rather than a single JAR. You can model your Maven depency after one of the following, depending on your targeted version of HBase. See Section 3.5, âUpgrading from 0.94.x to 0.96.xâ or Section 3.3, âUpgrading from 0.96.x to 0.98.xâ for more information. ++ +.Maven Dependency for HBase 0.98 +[source,xml] +---- +<dependency> + <groupId>org.apache.hbase</groupId> + <artifactId>hbase-client</artifactId> + <version>0.98.5-hadoop2</version> +</dependency> +---- ++ +.Maven Dependency for HBase 0.96 +[source,xml] +---- +<dependency> + <groupId>org.apache.hbase</groupId> + <artifactId>hbase-client</artifactId> + <version>0.96.2-hadoop2</version> +</dependency> +---- ++ +.Maven Dependency for HBase 0.94 +[source,xml] +---- +<dependency> + <groupId>org.apache.hbase</groupId> + <artifactId>hbase</artifactId> + <version>0.94.3</version> +</dependency> +---- + + +=== Architecture +How does HBase handle Region-RegionServer assignment and locality?:: + See <<regions.arch>>. + +=== Configuration +How can I get started with my first cluster?:: + See <<quickstart>>. + +Where can I learn about the rest of the configuration options?:: + See <<configuration>>. + +=== Schema Design / Data Access + +How should I design my schema in HBase?:: + See <<datamodel>> and <<schema>>. + +How can I store (fill in the blank) in HBase?:: + See <<supported.datatypes>>. + +How can I handle secondary indexes in HBase?:: + See <<secondary.indexes>>. + +Can I change a table's rowkeys?:: + This is a very common question. You can't. See <<changing.rowkeys>>. + +What APIs does HBase support?:: + See <<datamodel>>, <<architecture.client>>, and <<nonjava.jvm>>. + +=== MapReduce + +How can I use MapReduce with HBase?:: + See <<mapreduce>>. + +=== Performance and Troubleshooting + +How can I improve HBase cluster performance?:: + See <<performance>>. + +How can I troubleshoot my HBase cluster?:: + See <<trouble>>. + +=== Amazon EC2 + +I am running HBase on Amazon EC2 and...:: + EC2 issues are a special case. See <<trouble.ec2>> and <<perf.ec2>>. + +=== Operations + +How do I manage my HBase cluster?:: + See <<ops_mgt>>. + +How do I back up my HBase cluster?:: + See <<ops.backup>>. + +=== HBase in Action + +Where can I find interesting videos and presentations on HBase?:: + See <<other.info>>. + +:numbered: http://git-wip-us.apache.org/repos/asf/hbase/blob/cb77a925/src/main/asciidoc/_chapters/getting_started.adoc ---------------------------------------------------------------------- diff --git a/src/main/asciidoc/_chapters/getting_started.adoc b/src/main/asciidoc/_chapters/getting_started.adoc new file mode 100644 index 0000000..9e0b5a1 --- /dev/null +++ b/src/main/asciidoc/_chapters/getting_started.adoc @@ -0,0 +1,641 @@ +//// +/** + * + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +//// + += Getting Started +:doctype: book +:numbered: +:toc: left +:icons: font +:experimental: + +== Introduction + +<<quickstart,quickstart>> will get you up and running on a single-node, standalone instance of HBase, followed by a pseudo-distributed single-machine instance, and finally a fully-distributed cluster. + +[[quickstart]] +== Quick Start + +This guide describes setup of a standalone HBase instance running against the local filesystem. +This is not an appropriate configuration for a production instance of HBase, but will allow you to experiment with HBase. +This section shows you how to create a table in HBase using the +hbase shell+ CLI, insert rows into the table, perform put and scan operations against the table, enable or disable the table, and start and stop HBase. +Apart from downloading HBase, this procedure should take less than 10 minutes. + +WARNING: Local Filesystem and Durability This is fixed in HBase 0.98.3 and beyond. See link:https://issues.apache.org/jira/browse/HBASE-11272[HBASE-11272] and link:https://issues.apache.org/jira/browse/HBASE-11218[HBASE-11218]._ + +Using HBase with a local filesystem does not guarantee durability. +The HDFS local filesystem implementation will lose edits if files are not properly closed. +This is very likely to happen when you are experimenting with new software, starting and stopping the daemons often and not always cleanly. +You need to run HBase on HDFS to ensure all writes are preserved. +Running against the local filesystem is intended as a shortcut to get you familiar with how the general system works, as the very first phase of evaluation. +See link:https://issues.apache.org/jira/browse/HBASE-3696 and its associated issues for more details about the issues of running on the local filesystem. + +.Loopback IP - HBase 0.94.x and earlier + +NOTE: _The below advice is for hbase-0.94.x and older versions only. This is fixed in hbase-0.96.0 and beyond._ + +Prior to HBase 0.94.x, HBase expected the loopback IP address to be 127.0.0.1. Ubuntu and some other distributions default to 127.0.1.1 and this will cause problems for you . See link:http://blog.devving.com/why-does-hbase-care-about-etchosts/[Why does HBase care about /etc/hosts?] for detail. + + +.Example /etc/hosts File for Ubuntu +==== +The following _/etc/hosts_ file works correctly for HBase 0.94.x and earlier, on Ubuntu. Use this as a template if you run into trouble. +[listing] +---- +127.0.0.1 localhost +127.0.0.1 ubuntu.ubuntu-domain ubuntu +---- + +==== + + +=== JDK Version Requirements + +HBase requires that a JDK be installed. +See <<java,java>> for information about supported JDK versions. + +=== Get Started with HBase + +.Procedure: Download, Configure, and Start HBase +. Choose a download site from this list of link:http://www.apache.org/dyn/closer.cgi/hbase/[Apache Download Mirrors]. + Click on the suggested top link. + This will take you to a mirror of _HBase + Releases_. + Click on the folder named _stable_ and then download the binary file that ends in _.tar.gz_ to your local filesystem. + Be sure to choose the version that corresponds with the version of Hadoop you are likely to use later. + In most cases, you should choose the file for Hadoop 2, which will be called something like _hbase-0.98.3-hadoop2-bin.tar.gz_. + Do not download the file ending in _src.tar.gz_ for now. +. Extract the downloaded file, and change to the newly-created directory. ++ +---- + +$ tar xzvf hbase-<?eval ${project.version}?>-hadoop2-bin.tar.gz +$ cd hbase-<?eval ${project.version}?>-hadoop2/ +---- + +. For HBase 0.98.5 and later, you are required to set the `JAVA_HOME` environment variable before starting HBase. + Prior to 0.98.5, HBase attempted to detect the location of Java if the variables was not set. + You can set the variable via your operating system's usual mechanism, but HBase provides a central mechanism, _conf/hbase-env.sh_. + Edit this file, uncomment the line starting with `JAVA_HOME`, and set it to the appropriate location for your operating system. + The `JAVA_HOME` variable should be set to a directory which contains the executable file _bin/java_. + Most modern Linux operating systems provide a mechanism, such as /usr/bin/alternatives on RHEL or CentOS, for transparently switching between versions of executables such as Java. + In this case, you can set `JAVA_HOME` to the directory containing the symbolic link to _bin/java_, which is usually _/usr_. ++ +---- +JAVA_HOME=/usr +---- ++ +NOTE: These instructions assume that each node of your cluster uses the same configuration. +If this is not the case, you may need to set `JAVA_HOME` separately for each node. + +. Edit _conf/hbase-site.xml_, which is the main HBase configuration file. + At this time, you only need to specify the directory on the local filesystem where HBase and Zookeeper write data. + By default, a new directory is created under /tmp. + Many servers are configured to delete the contents of /tmp upon reboot, so you should store the data elsewhere. + The following configuration will store HBase's data in the _hbase_ directory, in the home directory of the user called [systemitem]+testuser+. + Paste the [markup]+<property>+ tags beneath the [markup]+<configuration>+ tags, which should be empty in a new HBase install. ++ +.Example _hbase-site.xml_ for Standalone HBase +==== +[source,xml] +---- + +<configuration> + <property> + <name>hbase.rootdir</name> + <value>file:///home/testuser/hbase</value> + </property> + <property> + <name>hbase.zookeeper.property.dataDir</name> + <value>/home/testuser/zookeeper</value> + </property> +</configuration> +---- +==== ++ +You do not need to create the HBase data directory. +HBase will do this for you. +If you create the directory, HBase will attempt to do a migration, which is not what you want. + +. The _bin/start-hbase.sh_ script is provided as a convenient way to start HBase. + Issue the command, and if all goes well, a message is logged to standard output showing that HBase started successfully. + You can use the +jps+ command to verify that you have one running process called `HMaster`. + In standalone mode HBase runs all daemons within this single JVM, i.e. + the HMaster, a single HRegionServer, and the ZooKeeper daemon. ++ +NOTE: Java needs to be installed and available. +If you get an error indicating that Java is not installed, but it is on your system, perhaps in a non-standard location, edit the _conf/hbase-env.sh_ file and modify the `JAVA_HOME` setting to point to the directory that contains _bin/java_ your system. + + +.Procedure: Use HBase For the First Time +. Connect to HBase. ++ +Connect to your running instance of HBase using the +hbase shell+ command, located in the _bin/_ directory of your HBase install. +In this example, some usage and version information that is printed when you start HBase Shell has been omitted. +The HBase Shell prompt ends with a `>` character. ++ +---- + +$ ./bin/hbase shell +hbase(main):001:0> +---- + +. Display HBase Shell Help Text. ++ +Type `help` and press Enter, to display some basic usage information for HBase Shell, as well as several example commands. +Notice that table names, rows, columns all must be enclosed in quote characters. + +. Create a table. ++ +Use the `create` command to create a new table. +You must specify the table name and the ColumnFamily name. ++ +---- + +hbase> create 'test', 'cf' +0 row(s) in 1.2200 seconds +---- + +. List Information About your Table ++ +Use the `list` command to ++ +---- + +hbase> list 'test' +TABLE +test +1 row(s) in 0.0350 seconds + +=> ["test"] +---- + +. Put data into your table. ++ +To put data into your table, use the `put` command. ++ +---- + +hbase> put 'test', 'row1', 'cf:a', 'value1' +0 row(s) in 0.1770 seconds + +hbase> put 'test', 'row2', 'cf:b', 'value2' +0 row(s) in 0.0160 seconds + +hbase> put 'test', 'row3', 'cf:c', 'value3' +0 row(s) in 0.0260 seconds +---- ++ +Here, we insert three values, one at a time. +The first insert is at `row1`, column `cf:a`, with a value of `value1`. +Columns in HBase are comprised of a column family prefix, `cf` in this example, followed by a colon and then a column qualifier suffix, `a` in this case. + +. Scan the table for all data at once. ++ +One of the ways to get data from HBase is to scan. +Use the +scan+ command to scan the table for data. +You can limit your scan, but for now, all data is fetched. ++ +---- + +hbase> scan 'test' +ROW COLUMN+CELL + row1 column=cf:a, timestamp=1403759475114, value=value1 + row2 column=cf:b, timestamp=1403759492807, value=value2 + row3 column=cf:c, timestamp=1403759503155, value=value3 +3 row(s) in 0.0440 seconds +---- + +. Get a single row of data. ++ +To get a single row of data at a time, use the +get+ command. ++ +---- + +hbase> get 'test', 'row1' +COLUMN CELL + cf:a timestamp=1403759475114, value=value1 +1 row(s) in 0.0230 seconds +---- + +. Disable a table. ++ +If you want to delete a table or change its settings, as well as in some other situations, you need to disable the table first, using the `disable` command. +You can re-enable it using the `enable` command. ++ +---- + +hbase> disable 'test' +0 row(s) in 1.6270 seconds + +hbase> enable 'test' +0 row(s) in 0.4500 seconds +---- ++ +Disable the table again if you tested the +enable+ command above: ++ +---- + +hbase> disable 'test' +0 row(s) in 1.6270 seconds +---- + +. Drop the table. ++ +To drop (delete) a table, use the `drop` command. ++ +---- + +hbase> drop 'test' +0 row(s) in 0.2900 seconds +---- + +. Exit the HBase Shell. ++ +To exit the HBase Shell and disconnect from your cluster, use the +quit+ command. +HBase is still running in the background. + + +.Procedure: Stop HBase +. In the same way that the _bin/start-hbase.sh_ script is provided to conveniently start all HBase daemons, the _bin/stop-hbase.sh_ script stops them. ++ +---- + +$ ./bin/stop-hbase.sh +stopping hbase.................... +$ +---- + +. After issuing the command, it can take several minutes for the processes to shut down. + Use the +jps+ to be sure that the HMaster and HRegionServer processes are shut down. + +[[quickstart_pseudo]] +=== Intermediate - Pseudo-Distributed Local Install + +After working your way through <<quickstart,quickstart>>, you can re-configure HBase to run in pseudo-distributed mode. +Pseudo-distributed mode means that HBase still runs completely on a single host, but each HBase daemon (HMaster, HRegionServer, and Zookeeper) runs as a separate process. +By default, unless you configure the `hbase.rootdir` property as described in <<quickstart,quickstart>>, your data is still stored in _/tmp/_. +In this walk-through, we store your data in HDFS instead, assuming you have HDFS available. +You can skip the HDFS configuration to continue storing your data in the local filesystem. + +.Hadoop Configuration +[NOTE] +==== +This procedure assumes that you have configured Hadoop and HDFS on your local system and or a remote system, and that they are running and available. +It also assumes you are using Hadoop 2. +Currently, the documentation on the Hadoop website does not include a quick start for Hadoop 2, but the guide at link:http://www.alexjf.net/blog/distributed-systems/hadoop-yarn-installation-definitive-guide is a good starting point. +==== + + +. Stop HBase if it is running. ++ +If you have just finished <<quickstart,quickstart>> and HBase is still running, stop it. +This procedure will create a totally new directory where HBase will store its data, so any databases you created before will be lost. + +. Configure HBase. ++ +Edit the _hbase-site.xml_ configuration. +First, add the following property. +which directs HBase to run in distributed mode, with one JVM instance per daemon. ++ +[source,xml] +---- + +<property> + <name>hbase.cluster.distributed</name> + <value>true</value> +</property> +---- ++ +Next, change the `hbase.rootdir` from the local filesystem to the address of your HDFS instance, using the `hdfs:////` URI syntax. +In this example, HDFS is running on the localhost at port 8020. ++ +[source,xml] +---- + +<property> + <name>hbase.rootdir</name> + <value>hdfs://localhost:8020/hbase</value> +</property> +---- ++ +You do not need to create the directory in HDFS. +HBase will do this for you. +If you create the directory, HBase will attempt to do a migration, which is not what you want. + +. Start HBase. ++ +Use the _bin/start-hbase.sh_ command to start HBase. +If your system is configured correctly, the +jps+ command should show the HMaster and HRegionServer processes running. + +. Check the HBase directory in HDFS. ++ +If everything worked correctly, HBase created its directory in HDFS. +In the configuration above, it is stored in _/hbase/_ on HDFS. +You can use the +hadoop fs+ command in Hadoop's _bin/_ directory to list this directory. ++ +---- + +$ ./bin/hadoop fs -ls /hbase +Found 7 items +drwxr-xr-x - hbase users 0 2014-06-25 18:58 /hbase/.tmp +drwxr-xr-x - hbase users 0 2014-06-25 21:49 /hbase/WALs +drwxr-xr-x - hbase users 0 2014-06-25 18:48 /hbase/corrupt +drwxr-xr-x - hbase users 0 2014-06-25 18:58 /hbase/data +-rw-r--r-- 3 hbase users 42 2014-06-25 18:41 /hbase/hbase.id +-rw-r--r-- 3 hbase users 7 2014-06-25 18:41 /hbase/hbase.version +drwxr-xr-x - hbase users 0 2014-06-25 21:49 /hbase/oldWALs +---- + +. Create a table and populate it with data. ++ +You can use the HBase Shell to create a table, populate it with data, scan and get values from it, using the same procedure as in <<shell_exercises,shell exercises>>. + +. Start and stop a backup HBase Master (HMaster) server. ++ +NOTE: Running multiple HMaster instances on the same hardware does not make sense in a production environment, in the same way that running a pseudo-distributed cluster does not make sense for production. +This step is offered for testing and learning purposes only. ++ +The HMaster server controls the HBase cluster. +You can start up to 9 backup HMaster servers, which makes 10 total HMasters, counting the primary. +To start a backup HMaster, use the +local-master-backup.sh+. +For each backup master you want to start, add a parameter representing the port offset for that master. +Each HMaster uses three ports (16010, 16020, and 16030 by default). The port offset is added to these ports, so using an offset of 2, the backup HMaster would use ports 16012, 16022, and 16032. +The following command starts 3 backup servers using ports 16012/16022/16032, 16013/16023/16033, and 16015/16025/16035. ++ +---- + +$ ./bin/local-master-backup.sh 2 3 5 +---- ++ +To kill a backup master without killing the entire cluster, you need to find its process ID (PID). The PID is stored in a file with a name like _/tmp/hbase-USER-X-master.pid_. +The only contents of the file are the PID. +You can use the +kill -9+ command to kill that PID. +The following command will kill the master with port offset 1, but leave the cluster running: ++ +---- + +$ cat /tmp/hbase-testuser-1-master.pid |xargs kill -9 +---- + +. Start and stop additional RegionServers ++ +The HRegionServer manages the data in its StoreFiles as directed by the HMaster. +Generally, one HRegionServer runs per node in the cluster. +Running multiple HRegionServers on the same system can be useful for testing in pseudo-distributed mode. +The +local-regionservers.sh+ command allows you to run multiple RegionServers. +It works in a similar way to the +local-master-backup.sh+ command, in that each parameter you provide represents the port offset for an instance. +Each RegionServer requires two ports, and the default ports are 16020 and 16030. +However, the base ports for additional RegionServers are not the default ports since the default ports are used by the HMaster, which is also a RegionServer since HBase version 1.0.0. +The base ports are 16200 and 16300 instead. +You can run 99 additional RegionServers that are not a HMaster or backup HMaster, on a server. +The following command starts four additional RegionServers, running on sequential ports starting at 16202/16302 (base ports 16200/16300 plus 2). ++ +---- + +$ .bin/local-regionservers.sh start 2 3 4 5 +---- ++ +To stop a RegionServer manually, use the +local-regionservers.sh+ command with the `stop` parameter and the offset of the server to stop. ++ +---- +$ .bin/local-regionservers.sh stop 3 +---- + +. Stop HBase. ++ +You can stop HBase the same way as in the <<quickstart,quickstart>> procedure, using the _bin/stop-hbase.sh_ command. + + +[[quickstart_fully_distributed]] +=== Advanced - Fully Distributed + +In reality, you need a fully-distributed configuration to fully test HBase and to use it in real-world scenarios. +In a distributed configuration, the cluster contains multiple nodes, each of which runs one or more HBase daemon. +These include primary and backup Master instances, multiple Zookeeper nodes, and multiple RegionServer nodes. + +This advanced quickstart adds two more nodes to your cluster. +The architecture will be as follows: + +.Distributed Cluster Demo Architecture +[cols="1,1,1,1", options="header"] +|=== +| Node Name | Master | ZooKeeper | RegionServer +| node-a.example.com | yes | yes | no +| node-b.example.com | backup | yes | yes +| node-c.example.com | no | yes | yes +|=== + +This quickstart assumes that each node is a virtual machine and that they are all on the same network. +It builds upon the previous quickstart, <<quickstart_pseudo,quickstart-pseudo>>, assuming that the system you configured in that procedure is now `node-a`. +Stop HBase on `node-a` before continuing. + +NOTE: Be sure that all the nodes have full access to communicate, and that no firewall rules are in place which could prevent them from talking to each other. +If you see any errors like `no route to host`, check your firewall. + +.Procedure: Configure Password-Less SSH Access + +`node-a` needs to be able to log into `node-b` and `node-c` (and to itself) in order to start the daemons. +The easiest way to accomplish this is to use the same username on all hosts, and configure password-less SSH login from `node-a` to each of the others. + +. On `node-a`, generate a key pair. ++ +While logged in as the user who will run HBase, generate a SSH key pair, using the following command: ++ +[source,bash] +---- +$ ssh-keygen -t rsa +---- ++ +If the command succeeds, the location of the key pair is printed to standard output. +The default name of the public key is _id_rsa.pub_. + +. Create the directory that will hold the shared keys on the other nodes. ++ +On `node-b` and `node-c`, log in as the HBase user and create a _.ssh/_ directory in the user's home directory, if it does not already exist. +If it already exists, be aware that it may already contain other keys. + +. Copy the public key to the other nodes. ++ +Securely copy the public key from `node-a` to each of the nodes, by using the +scp+ or some other secure means. +On each of the other nodes, create a new file called _.ssh/authorized_keys_ _if it does + not already exist_, and append the contents of the _id_rsa.pub_ file to the end of it. +Note that you also need to do this for `node-a` itself. ++ +---- +$ cat id_rsa.pub >> ~/.ssh/authorized_keys +---- + +. Test password-less login. ++ +If you performed the procedure correctly, if you SSH from `node-a` to either of the other nodes, using the same username, you should not be prompted for a password. + +. Since `node-b` will run a backup Master, repeat the procedure above, substituting `node-b` everywhere you see `node-a`. + Be sure not to overwrite your existing _.ssh/authorized_keys_ files, but concatenate the new key onto the existing file using the `>>` operator rather than the `>` operator. + +.Procedure: Prepare `node-a` + +`node-a` will run your primary master and ZooKeeper processes, but no RegionServers. +. Stop the RegionServer from starting on `node-a`. + +. Edit _conf/regionservers_ and remove the line which contains `localhost`. Add lines with the hostnames or IP addresses for `node-b` and `node-c`. ++ +Even if you did want to run a RegionServer on `node-a`, you should refer to it by the hostname the other servers would use to communicate with it. +In this case, that would be `node-a.example.com`. +This enables you to distribute the configuration to each node of your cluster any hostname conflicts. +Save the file. + +. Configure HBase to use `node-b` as a backup master. ++ +Create a new file in _conf/_ called _backup-masters_, and add a new line to it with the hostname for `node-b`. +In this demonstration, the hostname is `node-b.example.com`. + +. Configure ZooKeeper ++ +In reality, you should carefully consider your ZooKeeper configuration. +You can find out more about configuring ZooKeeper in <<zookeeper,zookeeper>>. +This configuration will direct HBase to start and manage a ZooKeeper instance on each node of the cluster. ++ +On `node-a`, edit _conf/hbase-site.xml_ and add the following properties. ++ +[source,bourne] +---- +<property> + <name>hbase.zookeeper.quorum</name> + <value>node-a.example.com,node-b.example.com,node-c.example.com</value> +</property> +<property> + <name>hbase.zookeeper.property.dataDir</name> + <value>/usr/local/zookeeper</value> +</property> +---- + +. Everywhere in your configuration that you have referred to `node-a` as `localhost`, change the reference to point to the hostname that the other nodes will use to refer to `node-a`. + In these examples, the hostname is `node-a.example.com`. + +.Procedure: Prepare `node-b` and `node-c` + +`node-b` will run a backup master server and a ZooKeeper instance. + +. Download and unpack HBase. ++ +Download and unpack HBase to `node-b`, just as you did for the standalone and pseudo-distributed quickstarts. + +. Copy the configuration files from `node-a` to `node-b`.and + `node-c`. ++ +Each node of your cluster needs to have the same configuration information. +Copy the contents of the _conf/_ directory to the _conf/_ directory on `node-b` and `node-c`. + + +.Procedure: Start and Test Your Cluster +. Be sure HBase is not running on any node. ++ +If you forgot to stop HBase from previous testing, you will have errors. +Check to see whether HBase is running on any of your nodes by using the +jps+ command. +Look for the processes `HMaster`, `HRegionServer`, and `HQuorumPeer`. +If they exist, kill them. + +. Start the cluster. ++ +On `node-a`, issue the +start-hbase.sh+ command. +Your output will be similar to that below. ++ +---- + +$ bin/start-hbase.sh +node-c.example.com: starting zookeeper, logging to /home/hbuser/hbase-0.98.3-hadoop2/bin/../logs/hbase-hbuser-zookeeper-node-c.example.com.out +node-a.example.com: starting zookeeper, logging to /home/hbuser/hbase-0.98.3-hadoop2/bin/../logs/hbase-hbuser-zookeeper-node-a.example.com.out +node-b.example.com: starting zookeeper, logging to /home/hbuser/hbase-0.98.3-hadoop2/bin/../logs/hbase-hbuser-zookeeper-node-b.example.com.out +starting master, logging to /home/hbuser/hbase-0.98.3-hadoop2/bin/../logs/hbase-hbuser-master-node-a.example.com.out +node-c.example.com: starting regionserver, logging to /home/hbuser/hbase-0.98.3-hadoop2/bin/../logs/hbase-hbuser-regionserver-node-c.example.com.out +node-b.example.com: starting regionserver, logging to /home/hbuser/hbase-0.98.3-hadoop2/bin/../logs/hbase-hbuser-regionserver-node-b.example.com.out +node-b.example.com: starting master, logging to /home/hbuser/hbase-0.98.3-hadoop2/bin/../logs/hbase-hbuser-master-nodeb.example.com.out +---- ++ +ZooKeeper starts first, followed by the master, then the RegionServers, and finally the backup masters. + +. Verify that the processes are running. ++ +On each node of the cluster, run the +jps+ command and verify that the correct processes are running on each server. +You may see additional Java processes running on your servers as well, if they are used for other purposes. ++ +.`node-a` `jps` Output +==== +---- + +$ jps +20355 Jps +20071 HQuorumPeer +20137 HMaster +---- +==== ++ +.`node-b` `jps` Output +==== +---- +$ jps +15930 HRegionServer +16194 Jps +15838 HQuorumPeer +16010 HMaster +---- +==== ++ +.`node-a` `jps` Output +==== +---- +$ jps +13901 Jps +13639 HQuorumPeer +13737 HRegionServer +---- +==== ++ +.ZooKeeper Process Name +[NOTE] +==== +The `HQuorumPeer` process is a ZooKeeper instance which is controlled and started by HBase. +If you use ZooKeeper this way, it is limited to one instance per cluster node, , and is appropriate for testing only. +If ZooKeeper is run outside of HBase, the process is called `QuorumPeer`. +For more about ZooKeeper configuration, including using an external ZooKeeper instance with HBase, see <<zookeeper,zookeeper>>. +==== + +. Browse to the Web UI. ++ +.Web UI Port Changes +NOTE: Web UI Port Changes ++ +In HBase newer than 0.98.x, the HTTP ports used by the HBase Web UI changed from 60010 for the Master and 60030 for each RegionServer to 16610 for the Master and 16030 for the RegionServer. + ++ +If everything is set up correctly, you should be able to connect to the UI for the Master `http://node-a.example.com:16610/` or the secondary master at `http://node-b.example.com:16610/` for the secondary master, using a web browser. +If you can connect via `localhost` but not from another host, check your firewall rules. +You can see the web UI for each of the RegionServers at port 16630 of their IP addresses, or by clicking their links in the web UI for the Master. + +. Test what happens when nodes or services disappear. ++ +With a three-node cluster like you have configured, things will not be very resilient. +Still, you can test what happens when the primary Master or a RegionServer disappears, by killing the processes and watching the logs. + + +=== Where to go next + +The next chapter, <<configuration,configuration>>, gives more information about the different HBase run modes, system requirements for running HBase, and critical configuration areas for setting up a distributed HBase cluster.
