Trivial-first look at HBase, trivial-HBase

Trivial-first look at HBase, trivial-HBase

 

Version 0.95
In hbase standalone mode, all services run on one JVM, including HBase and zookeeper. The local file system is used.

Logs are stored in the logs folder by default.

Basic commands:
Create 'table', 'cf '// create a table named after the table, and the cloumn family is cf
Put 'table', 'row1', 'cf: A', 'value1' // insert a piece of data into the table. row1 is the key value, a is the column name, And value1 is the value.
List 'table' // list all tables. Table is not the table name
Scan 'table' // view all data in the table
Get 'table', 'row1' // obtain data
Disable 'table '//?
Drop 'table'; // delete a table

Hbase divides default configuration files and user-defined configuration files

Hbase requires that the local return address must be 127.0.0.1, rather than 127.0.1.1. Ubuntu is 127.0.1.1 by default.

The common Linux Maximum file handle cannot meet hbase requirements. The default value is 1024, which is set to 10 KB.

Sync persistent Synchronization

Hbase runs on 0.20.205.x and sync must be enabled explicitly. dfs. support. append

Hadoop. jar of hbase must be consistent with hadoop. jar of hadoop.

Hadoop hdfs has an upper limit on the number of files processed at the same time, which must be at least 4096, dfs. datanode. max. xcievers

Hbase is divided into standalone, pseudo-distributed, and fully distributed. Same as hadoop

Hbase data directory hbase. rootdir should be created by itself rather than by itself

To use fully distributed mode, set hbase. cluster. distributed to true.

Hbase conf/regionservers is equivalent to hadoop conf/slaves or etc/slaves.

A Distributed hbase depends on a zookeeper cluster.

Hbase default master port: 60000

Hbase determines that the downtime is 3 minutes by default

Hbase tables are sorted by keys.

 

Is hbase authoritative?

HBase is a distributed, column-oriented open source database. This technology comes from Fay Chang
The Google paper "Bigtable: a distributed storage system for structured data ". Just as Bigtable uses the Google File System (File
Like distributed data storage, HBase provides Bigtable-like capabilities on top of Hadoop. HBase is a subproject of Apache Hadoop project. Unlike general relational databases, HBase is a database suitable for storing unstructured data. Another difference is that HBase is column-based instead of Row-based.
For more information about open source, go to the LUPA community.
 
Advice on hbase pseudo Distribution

Add in the hbase-default.xml File
<Property>
<Name> hbase. zookeeper. quorum </name>
<Value> the ip address of all your nodes. If it is in a pseudo distributed environment, it is localhost. </value>
Example: <value> 192.168.1.2, 192.168.1.1 </value>
</Property>

Check whether the file 127.0.1.1 is changed to 127.0.0.1 in the/etc/hosts file. If the file is not changed, change it to 127.0.0.1, which corresponds to the localhost and host name respectively.