hbase的四种压缩格式

Hbase支持的压缩格式：

hbase支持的压缩格式：GZ（GZIP）,LZ0，LZ4，Snappy

GZ:用于冷数据压缩，与Snappy和LZ0相比，GZIP的压缩率更高，但是更消耗CPU，解压/压缩速度更慢。

Snappy和LZ0：用于热数据压缩，占用CPU少，解压/压缩速度比GZ快，但是压缩率不如GZ高。

Snappy与LZ0相比，Snappy整体性能优于LZ0，Snappy压缩率比LZ0更低，但是解压/压缩速度更快。

LZ4与LZ0相比，LZ4的压缩率和LZ0的压缩率相差不多，但是LZ4的解压/压缩速度更快。

多数情况下，选择Snppy或LZ0是比较好的选择，因为它们的压缩开销底，能节省空间。

建表时指定压缩格式

hbase(main):013:0> create 'test3',{NAME=>'f1'},{NAME=>'f2',COMPRESSION=>'Snappy'}
0 row(s) in 1.2740 seconds
 
=> Hbase::Table - test3
hbase(main):014:0> desc 'test3'
Table test3 is ENABLED                                                                                                                                             
test3                                                                                                                                                              
COLUMN FAMILIES DESCRIPTION                                                                                                                                        
{NAME => 'f1', BLOOMFILTER => 'ROW',VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE',DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRESS
ION => 'NONE', MIN_VERSIONS => '0',BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE =>'0'}                                                           
{NAME => 'f2', BLOOMFILTER => 'ROW',VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE',DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRESS
ION => 'SNAPPY', MIN_VERSIONS => '0',BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE =>'0'}                                                        
2 row(s) in 0.0300 seconds

hbase(main):002:0> create 'test4' ,{NAME=>'f1'},{NAME=>'f2',COMPRESSION=>'GZ'}
0 row(s) in 1.4900 secOnds=> Hbase::Table - test4
hbase(main):003:0> desc 'test4'
Table test4 is ENABLED                                                                                                                                              
test4                                                                                                                                                               
COLUMN FAMILIES DESCRIPTION                                                                                                                                         
{NAME => 'f1', BLOOMFILTER => 'ROW', VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE', DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRESS
ION => 'NONE', MIN_VERSIONS => '0', BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE => '0'}                                                           
{NAME => 'f2', BLOOMFILTER => 'ROW', VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE', DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRESS
ION => 'GZ', MIN_VERSIONS => '0', BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE => '0'}                                                             
2 row(s) in 0.1290 seconds

建表后修改columnfamily压缩格式

正确做法是先disable表，再修改列族压缩格式，enbale表后做major_compact操作。

如下：

hbase(main):004:0> desc 'test1'
Table test1 is ENABLED                                                                                                                                             
test1                                                                                                                                                              
COLUMN FAMILIES DESCRIPTION                                                                                                                                        
{NAME => 'f1', BLOOMFILTER => 'ROW',VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE',DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRESS
ION => 'NONE', MIN_VERSIONS => '0',BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE =>'0'}                                                          
{NAME => 'f2', BLOOMFILTER => 'ROW',VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE',DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRESS
ION => 'NONE', MIN_VERSIONS => '0',BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE =>'0'}                                                          
2 row(s) in 0.0230 seconds
 
hbase(main):005:0> disable 'test1'
0 row(s) in 2.2870 seconds
 
hbase(main):006:0> alter 'test1' ,{NAME=>'f1',COMPRESSION=>'Snappy'}
Updating all regions with the new schema...
1/1 regions updated.
Done.
0 row(s) in 1.9510 seconds
 
hbase(main):007:0> enable 'test1'
0 row(s) in 1.2820 seconds
 
hbase(main):008:0> desc 'test1'
Table test1 is ENABLED                                                                                                                                              
test1                                                                                                                                                              
COLUMN FAMILIES DESCRIPTION                                                                                                                                        
{NAME => 'f1', BLOOMFILTER => 'ROW',VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE',DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRESS
ION => 'SNAPPY', MIN_VERSIONS => '0',BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE =>'0'}                                                         
{NAME => 'f2', BLOOMFILTER => 'ROW',VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE',DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRESS
ION => 'NONE', MIN_VERSIONS => '0',BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE =>'0'}                                                          
2 row(s) in 0.0310 seconds
 
hbase(main):009:0> major_compact 'test1'
0 row(s) in 0.1380 seconds
 
hbase(main):010:0> desc 'test1'
Table test1 is ENABLED                                                                                                                                             
test1                                                                                                                                                              
COLUMN FAMILIES DESCRIPTION                                                                                                                                        
{NAME => 'f1', BLOOMFILTER => 'ROW',VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE',DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRESS
ION => 'SNAPPY', MIN_VERSIONS => '0',BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE =>'0'}                                                        
{NAME => 'f2', BLOOMFILTER => 'ROW',VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE',DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRESS
ION => 'NONE', MIN_VERSIONS => '0',BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE =>'0'}                                                          
2 row(s) in 0.0260 seconds

但是没有disable表，也不做major_compact，列族压缩格式也修改成功了（暂时不知道原因）。

hbase(main):001:0> desc 'test'
Table test is ENABLED                                                                                                                                               
test                                                                                                                                                                
COLUMN FAMILIES DESCRIPTION                                                                                                                                         
{NAME => 'fam1', BLOOMFILTER => 'ROW', VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS => 'FALSE', DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRE
SSION => 'NONE', MIN_VERSIONS => '0', BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE => '0'}                                                         
1 row(s) in 0.3680 seconds

hbase(main):002:0> alter 'test',{NAME=>'fam1',COMPRESSION=>'LZ4'}
Updating all regions with the new schema...
1/1 regions updated.
Done.
0 row(s) in 2.0460 seconds

hbase(main):003:0> desc 'test'
Table test is ENABLED                                                                                                                                               
test                                                                                                                                                               
COLUMN FAMILIES DESCRIPTION                                                                                                                                        
{NAME => 'fam1', BLOOMFILTER =>'ROW', VERSIONS => '1', IN_MEMORY => 'false', KEEP_DELETED_CELLS =>'FALSE', DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', COMPRE
SSION => 'LZ4', MIN_VERSIONS => '0',BLOCKCACHE => 'true', BLOCKSIZE => '65536', REPLICATION_SCOPE =>'0'}                                                          
1 row(s) in 0.0280 seconds