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HBASE-24271 Set values in conf/hbase-site.xml that enable running o…
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…n `LocalFileSystem` out of the box

Simplify the new user experience shipping a configuration that enables
a fresh checkout or tarball distribution to run in standalone mode
without direct user configuration. This change restores the behavior
we had when running on Hadoop 2.8 and earlier.

Patch for master includes an update to the book. This change will be
omitted when backporting to earlier branches.

Signed-off-by: stack <stack@apache.org>
Signed-off-by: Josh Elser <elserj@apache.org>
Signed-off-by: Duo Zhang <zhangduo@apache.org>
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ndimiduk committed May 14, 2020
1 parent 8148c58 commit 7e295e7
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1 change: 1 addition & 0 deletions .gitignore
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Expand Up @@ -23,3 +23,4 @@ linklint/
.java-version
*.log
**/*.log
tmp
34 changes: 32 additions & 2 deletions conf/hbase-site.xml
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@@ -1,8 +1,7 @@
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!--
/**
*
/*
* 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
Expand All @@ -21,4 +20,35 @@
*/
-->
<configuration>
<!--
The following properties are set for running HBase as a single process on a
developer workstation. With this configuration, HBase is running in
"stand-alone" mode and without a distributed file system. In this mode, and
without further configuration, HBase and ZooKeeper data are stored on the
local filesystem, in a path under the value configured for `hbase.tmp.dir`.
This value is overridden from its default value of `/tmp` because many
systems clean `/tmp` on a regular basis. Instead, it points to a path within
this HBase installation directory.
Running against the `LocalFileSystem`, as opposed to a distributed
filesystem, runs the risk of data integrity issues and data loss. Normally
HBase will refuse to run in such an environment. Setting
`hbase.unsafe.stream.capability.enforce` to `false` overrides this behavior,
permitting operation. This configuration is for the developer workstation
only and __should not be used in production!__
See also https://hbase.apache.org/book.html#standalone_dist
-->
<property>
<name>hbase.cluster.distributed</name>
<value>false</value>
</property>
<property>
<name>hbase.tmp.dir</name>
<value>${env.HBASE_HOME:-.}/tmp</value>
</property>
<property>
<name>hbase.unsafe.stream.capability.enforce</name>
<value>false</value>
</property>
</configuration>
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@@ -1,4 +1,4 @@
/**
/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
Expand Down Expand Up @@ -349,7 +349,7 @@ public static void setWALRootDir(final Configuration c, final Path root) {
public static FileSystem getWALFileSystem(final Configuration c) throws IOException {
Path p = getWALRootDir(c);
FileSystem fs = p.getFileSystem(c);
// hadoop-core does fs caching, so need to propogate this if set
// hadoop-core does fs caching, so need to propagate this if set
String enforceStreamCapability = c.get(UNSAFE_STREAM_CAPABILITY_ENFORCE);
if (enforceStreamCapability != null) {
fs.getConf().set(UNSAFE_STREAM_CAPABILITY_ENFORCE, enforceStreamCapability);
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77 changes: 7 additions & 70 deletions src/main/asciidoc/_chapters/getting_started.adoc
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Expand Up @@ -77,76 +77,12 @@ $ cd hbase-{Version}/
# The java implementation to use.
export JAVA_HOME=/usr/jdk64/jdk1.8.0_112
+
. Edit _conf/hbase-site.xml_, which is the main HBase configuration file.
At this time, you need to specify the directory on the local filesystem where HBase and ZooKeeper write data and acknowledge some risks.
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 `testuser`.
Paste the `<property>` tags beneath the `<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>
<property>
<name>hbase.unsafe.stream.capability.enforce</name>
<value>false</value>
<description>
Controls whether HBase will check for stream capabilities (hflush/hsync).
Disable this if you intend to run on LocalFileSystem, denoted by a rootdir
with the 'file://' scheme, but be mindful of the NOTE below.
WARNING: Setting this to false blinds you to potential data loss and
inconsistent system state in the event of process and/or node failures. If
HBase is complaining of an inability to use hsync or hflush it's most
likely not a false positive.
</description>
</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.
+
NOTE: The _hbase.rootdir_ in the above example points to a directory
in the _local filesystem_. The 'file://' prefix is how we denote local
filesystem. You should take the WARNING present in the configuration example
to heart. In standalone mode HBase makes use of the local filesystem abstraction
from the Apache Hadoop project. That abstraction doesn't provide the durability
promises that HBase needs to operate safely. This is fine for local development
and testing use cases where the cost of cluster failure is well contained. It is
not appropriate for production deployments; eventually you will lose data.
To home HBase on an existing instance of HDFS, set the _hbase.rootdir_ to point at a
directory up on your instance: e.g. _hdfs://namenode.example.org:8020/hbase_.
For more on this variant, see the section below on Standalone HBase over HDFS.
. 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.
Go to _http://localhost:16010_ to view the HBase Web UI.
+
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_ on your system.
[[shell_exercises]]
Expand Down Expand Up @@ -306,7 +242,7 @@ The above has shown you how to start and stop a standalone instance of HBase.
In the next sections we give a quick overview of other modes of hbase deploy.
[[quickstart_pseudo]]
=== Pseudo-Distributed Local Install
=== Pseudo-Distributed for Local Testing
After working your way through <<quickstart,quickstart>> standalone mode,
you can re-configure HBase to run in pseudo-distributed mode.
Expand Down Expand Up @@ -348,8 +284,8 @@ First, add the following property which directs HBase to run in distributed mode
</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. Be sure to either remove the entry for `hbase.unsafe.stream.capability.enforce` or set it to true.
Next, add a configuration for `hbase.rootdir`, pointing 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]
----
Expand All @@ -361,8 +297,9 @@ In this example, HDFS is running on the localhost at port 8020. Be sure to eithe
----
+
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.
HBase will do this for you. If you create the directory, HBase will attempt to do a migration, which is not what you want.
+
Finally, remove existing configuration for `hbase.tmp.dir` and `hbase.unsafe.stream.capability.enforce`,
. Start HBase.
+
Expand Down Expand Up @@ -449,7 +386,7 @@ You can stop HBase the same way as in the <<quickstart,quickstart>> procedure, u
[[quickstart_fully_distributed]]
=== Advanced - Fully Distributed
=== Fully Distributed for Production
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.
Expand Down

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