Apache HBase参考指南：第三版精华解析 - CSDN文库

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"Apache HBase Reference Guide 3.00 PDF，是关于Apache HBase查询指导的第三版文档，由Apache HBase团队编写。该指南详细介绍了HBase的配置、升级、数据模型以及schema设计等多个方面，旨在帮助用户理解和操作HBase分布式数据库。" Apache HBase是一种基于Google Bigtable理念构建的开源、分布式、版本化NoSQL数据库，主要用于存储海量结构化数据。在《Apache HBase Reference Guide》中，你可以找到以下关键知识点： 1. Getting Started：这部分为初学者提供了快速入门的指引，包括对HBase的简单介绍和独立运行模式下的快速启动步骤。 2. Apache HBase Configuration：详细讲解了HBase的配置文件、基本配置需求和不同运行模式，如单机模式和分布式模式，以及如何验证安装是否成功。 3. HBase Run Modes：描述了HBase的运行模式，包括单机模式和分布式模式，帮助用户理解在不同环境下的操作和管理。 4. Default Configuration和Example Configurations：列出了默认配置设置，并提供了示例配置，以适应不同的应用场景。 5. Dynamic Configuration：讨论了如何动态地更改HBase的配置，这对于管理和优化HBase集群至关重要。 6. Upgrading：涵盖了HBase的版本兼容性、回滚策略和升级路径，为用户提供了升级过程中的注意事项和步骤。 7. The Apache HBase Shell：这部分介绍了使用Ruby进行脚本编程，非交互式模式下运行shell，以及在操作系统脚本中使用HBase shell的技巧，还涉及如何从命令文件读取HBase shell命令。 8. Data Model：深入解释了HBase的数据模型，包括概念视图（如Namespace、Table、Row、Column Family和Cell）和物理视图，以及版本控制、排序规则和列元数据等。 9. ACID Properties：讨论了HBase如何提供原子性、一致性、隔离性和持久性的事务处理能力。 10. HBase and Schema Design：这部分指导用户如何设计适合HBase的高效Schema，以实现最佳性能和可扩展性。《Apache HBase Reference Guide》是一份全面的参考资料，无论你是刚接触HBase的新手还是寻求优化现有集群的管理员，都能从中受益。它提供了深入的技术细节，帮助你理解和利用HBase的强大功能来处理大规模数据。

hbase(main):006:0> scan 'test'

ROW COLUMN+CELL

Êrow1 column=cf:a, timestamp=1421762485768,

value=value1

Êrow2 column=cf:b, timestamp=1421762491785,

value=value2

Êrow3 column=cf:c, timestamp=1421762496210,

value=value3

3 row(s) in 0.0230 seconds

7. Get a single row of data.

To get a single row of data at a time, use the get command.

hbase(main):007:0> get 'test', 'row1'

COLUMN CELL

Êcf:a timestamp=1421762485768, value=value1

1 row(s) in 0.0350 seconds

8. 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(main):008:0> disable 'test'

0 row(s) in 1.1820 seconds

hbase(main):009:0> enable 'test'

0 row(s) in 0.1770 seconds

Disable the table again if you tested the enable command above:

hbase(main):010:0> disable 'test'

0 row(s) in 1.1820 seconds

9. Drop the table.

To drop (delete) a table, use the drop command.

hbase(main):011:0> drop 'test'

0 row(s) in 0.1370 seconds

10. Exit the HBase Shell.

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To exit the HBase Shell and disconnect from your cluster, use the quit command. HBase is still

running in the background.

Procedure: Stop HBase

1. 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....................

$

2. 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.

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.

2.3. Pseudo-Distributed Local Install

After working your way through quickstart standalone mode, 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: in standalone mode all daemons ran in one jvm process/instance. By default, unless you

configure the hbase.rootdir property as described in 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

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. The guide on Setting up a Single Node Cluster in

the Hadoop documentation is a good starting point.

1. Stop HBase if it is running.

If you have just finished 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.

2. 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.

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

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 two ports (16000 and 16010 by default). The port

offset is added to these ports, so using an offset of 2, the backup HMaster would use ports 16002

and 16012. The following command starts 3 backup servers using ports 16002/16012,

16003/16013, and 16005/16015.

$ ./bin/local-master-backup.sh start 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 is 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

7. 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.

Since HBase version 1.1.0, HMaster doesn’t use region server ports, this leaves 10 ports (16020 to

16029 and 16030 to 16039) to be used for RegionServers. For supporting additional

RegionServers, set environment variables HBASE_RS_BASE_PORT and

HBASE_RS_INFO_BASE_PORT to appropriate values before running script local-

regionservers.sh. e.g. With values 16200 and 16300 for base ports, 99 additional RegionServers

can be supported, on a server. The following command starts four additional RegionServers,

running on sequential ports starting at 16022/16032 (base ports 16020/16030 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

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8. Stop HBase.

You can stop HBase the same way as in the quickstart procedure, using the bin/stop-hbase.sh

command.

2.4. 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:

Table 1. Distributed Cluster Demo Architecture

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, Pseudo-Distributed Local Install, assuming that the

system you configured in that procedure is now node-a. Stop HBase on node-a before continuing.



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 Passwordless 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.

1. 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:

$ 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.

2. 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

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