第一次写系列博客，最近项目中用到了hbase，本文从以下几点来探讨下hbase，做个简单的了解。官网链接：https://hbase.apache.org/

hbase是什么 ？

• 先看下官网介绍

Apache HBase is the Hadoop database, a distributed, scalable, big data store.

看下来得到这几个关键字：Hadoop 、数据库、分布式、可扩展、大数据量

hbase的由来 ？

Use Apache HBase when you need random, realtime read/write access to your Big Data. This project's goal is the hosting of very large tables -- billions of rows X millions of columns -- atop clusters of commodity hardware.
Apache HBase is an open-source, distributed, versioned, non-relational database modeled after Google's Bigtable: A Distributed Storage System for Structured Data by Chang et al.
Just as Bigtable leverages the distributed data storage provided by the Google File System, Apache HBase provides Bigtable-like capabilities on top of Hadoop and HDFS.

上面这段介绍，对hbase概括的很全了：

1. 对大数据进行随机、实时的读写
2. 支持几十亿行、几百万列的存储
3. 开源的、分布式的、版本化的非关系型数据库
4. 仿照Google的Bigtable，依托Hadoop 的 HDFS文件系统

hbase的特性

1 Linear and modular scalability.
2 Strictly consistent reads and writes.
3 Automatic and configurable sharding of tables
4 Automatic failover support between RegionServers.
5 Convenient base classes for backing Hadoop MapReduce jobs with Apache HBase tables.
6 Easy to use Java API for client access.
7 Block cache and Bloom Filters for real-time queries.
8 Query predicate push down via server side Filters
9 Thrift gateway and a REST-ful Web service that supports XML, Protobuf, and binary data encoding options
10 Extensible jruby-based (JIRB) shell
11 Support for exporting metrics via the Hadoop metrics subsystem to files or Ganglia; or via JMX

1. 线性的 && 模块可伸缩性

2. 读写严格一致性

3. 自动配置分片

4. RegionServers间自动故障转移

5. 很方便的支持Hadoop MapReduce作业（不太理解）

6. 易于使用Java api客户端访问

7. 实时查询的块缓存和布隆过滤器

8. 通过服务器端过滤器查询谓词下推

9. Thrift网关和REST-ful Web服务，支持XML，Protobuf和二进制数据编码选项

10. 个可扩展的基于Jruby的（JIRB）外壳

11. 支持通过Hadoop指标子系统将指标导出到文件或Ganglia； 或通过JMX

后面这4个指标特性没有看太懂。

hbase的结构 ？

hbase能用来做什么 ？