Apache HBase 官方参考指南 - CSDN文库

Hbase官方手册.pdf

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"Hbase官方手册.pdf" Apache HBase 是一个分布式、版本化、列族式的NoSQL数据库，它构建在Hadoop文件系统（HDFS）之上，提供了高吞吐量的数据读写能力，适合大规模数据存储。这份官方手册详细介绍了如何使用和配置HBase，以及其核心概念和操作。 1. **Getting Started**：这部分引导读者快速了解HBase，包括介绍HBase的基本概念和启动独立模式的HBase实例。 2. **Apache HBase Configuration**：这部分详细阐述了HBase的配置过程，包括配置文件、基本要求和运行模式。配置文件章节讲解了hbase-site.xml和regionservers等文件的作用，基本要求涵盖了运行HBase所需的基础软件和硬件环境，而运行模式则对比了单机和分布式模式的区别。 3. **HBase Run Modes**：讨论了两种主要的运行模式，即独立模式和分布式模式。独立模式适用于开发和测试，而分布式模式则用于生产环境，能够处理大量数据和并发请求。 4. **Running and Confirming Your Installation**：这部分指导用户如何启动、检查和验证HBase的安装是否成功。 5. **Default Configuration** 和 **Example Configurations**：解释了HBase的默认配置，并提供了一些示例配置，帮助用户根据实际需求调整设置。 6. **The Important Configurations**：列出了一些关键的配置参数，这些参数对HBase的性能和稳定性至关重要。 7. **Dynamic Configuration**：讨论了如何在运行时动态修改配置，以适应不断变化的环境。 8. **Upgrading**：这部分包含了关于HBase版本兼容性、回滚和升级路径的信息，是进行版本更新的重要参考。 9. **The Apache HBase Shell**：HBase shell是一个交互式命令行工具，用于执行管理任务和查询数据。手册详细介绍了如何使用Ruby进行脚本编程，以及非交互模式、OSScripts和命令文件的使用方法。 10. **Data Model**：HBase的数据模型由概念视图和物理视图组成，包括命名空间、表、行、列族和单元格等核心概念。此外，还涉及版本管理和排序规则。 11. **Conceptual View** 和 **Physical View**：从抽象和实际存储的角度解释了数据在HBase中的组织方式。 12. **Namespace, Table, Row, ColumnFamily, Cells**：这些章节分别详细阐述了这些数据结构的特性和操作。 13. **Data Model Operations**：涵盖了对HBase数据模型的各种操作，如创建、删除和查询。 14. **Versions**：介绍了HBase如何处理数据的不同版本，支持多版本并发控制。 15. **Sort Order**：讨论了HBase中的数据排序机制，这对于数据检索和分析非常重要。 16. **Column Metadata**：列元数据是描述列族和列属性的信息，这部分介绍了如何管理和使用这些元数据。通过这份手册，读者可以深入理解HBase的工作原理，掌握配置、管理和操作HBase的最佳实践，从而有效地利用HBase处理大规模的非结构化数据。

hbase(main):002:0> list 'test'

TABLE

test

1 row(s) in 0.0180 seconds

=> ["test"]

Now use the describe command to see details, including configuration defaults

hbase(main):003:0> describe 'test'

Table test is ENABLED

test

COLUMN FAMILIES DESCRIPTION

{NAME => 'cf', VERSIONS => '1', EVICT_BLOCKS_ON_CLOSE => 'false',

NEW_VERSION_BEHAVIOR => 'false', KEEP_DELETED_CELLS => 'FALSE', CACHE_DATA_ON_WRITE

=>

'false', DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', MIN_VERSIONS => '0',

REPLICATION_SCOPE => '0', BLOOMFILTER => 'ROW', CACHE_INDEX_ON_WRITE => 'f

alse', IN_MEMORY => 'false', CACHE_BLOOMS_ON_WRITE => 'false',

PREFETCH_BLOCKS_ON_OPEN => 'false', COMPRESSION => 'NONE', BLOCKCACHE => 'true',

BLOCKSIZE

Ê=> '65536'}

1 row(s)

Took 0.9998 seconds

5. Put data into your table.

To put data into your table, use the put command.

hbase(main):003:0> put 'test', 'row1', 'cf:a', 'value1'

0 row(s) in 0.0850 seconds

hbase(main):004:0> put 'test', 'row2', 'cf:b', 'value2'

0 row(s) in 0.0110 seconds

hbase(main):005:0> put 'test', 'row3', 'cf:c', 'value3'

0 row(s) in 0.0100 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.

6. 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.

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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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