MapRTableMappingRules (MapR-M7 HBase Client)

java.lang.Object
- org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules
- - com.mapr.fs.hbase.MapRTableMappingRules

```
public class MapRTableMappingRules
extends org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules
```
The TableMappingRule class encapsulate the rules for deciding if a table name map to HBase table or a M7 table.
Apache HBase has its own flat namespace (no slashes in a table name). This namespace must be supported by MapR, because
1. A customer may run Apache HBase on a MapR cluster.
2. A customer may have applications with hard-coded table names which they want to migrate to M7.
3. A single client JAR supports both M7 and Apache HBase.
The following rules determine, based on the table name/path, whether it's a M7 table or an Apache HBase table.

Pattern Table type

a/b/c (anything with a slash) M7

maprfs://... M7

hbase://mytable1 Apache HBase

mytable1 (no slash) (See notes below)

Notes:
If a mapping for this table name exists in the client configuration, this is a M7 table. Otherwise, it is a Apache HBase table.

HBase table namespace mappings

As explained in FS-NS-003, there needs to be a way to determine whether a flat table name (no slashes and doesn't start with hbase://) should be treated as a Apache HBase table or a M7 table. This is accomplished with a client-side configuration "hbase.table.namespace.mappings" .
Example 1:
<name>hbase.table.namespace.mappings</name> <value>*:/tables</value>

Any flat table name "foo" is treated as a M7 table "/tables/foo".
Example 2:
<name>hbase.table.namespace.mappings</name> <value>mytable1:/user/aaa,mytable2:/user/bbb/</value>
- The flat table name "mytable1" is treated as a M7 table "/user/aaa" (if the flat table name in the mapping is not a glob and there is no "/" at the end of target path, the target path is treated as alias).
- The flat table name "mytable2" is treated as a M7 table at "/user/bbb/mytable2".
- All other flat table names are treated as Apache HBase tables.
Example 3:
<name>hbase.table.namespace.mappings</name> <value> mytable1:/user/aaa,mapr-*:/user/bbb,*:/tables</value>

Mappings are evaluated in order. The flat table name "mytable1" is treated as a M7 table "/user/aaa. Any flat table with name starting with "mapr-" is treated as a M7 table under "/user/bbb/". All other flat table name, say, "foo" is treated as a M7 table under "/tables/".
Example 4 (same as not specifying this parameter at all):
<name>hbase.table.namespace.mappings</name> <value></value>
All flat table names are treated as Apache HBase tables. IMPORTANT: This class functionality has been duplicated in fcclusterconf.h to provide similar helper methods for MapRDB C APIs. Any change in functionality over here should be reflected in that class as well, and vice-versa.

Pattern	Table type
a/b/c (anything with a slash)	M7
maprfs://...	M7
hbase://mytable1	Apache HBase
mytable1 (no slash)	(See notes below)

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules
  org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules.ClusterType

Field Summary

Fields
Modifier and Type	Field and Description
`static java.lang.String`	`HBASE_ENGINE`
`static org.apache.hadoop.fs.Path`	`HBASE_PREFIX_PATH`
`static java.lang.String`	`HBASE_TABLE_NAMESPACE_MAPPINGS`
`static java.lang.String`	`MAPR_ENGINE`

Fields inherited from class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules
HBASE_AVAILABLE, HBASE_PREFIX, inHBaseService_, INSTANCE, MAPRFS_PREFIX

Constructor Summary

Constructors
Constructor and Description
`MapRTableMappingRules(org.apache.hadoop.conf.Configuration conf)` Creates a table mapping rule object based on the value of 'hbase.table.namespace.mappings' parameter in the `conf`.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules.ClusterType`	`getClusterType()`
`org.apache.hadoop.fs.Path`	`getDefaultTablePath()`
`protected org.apache.hadoop.fs.FileSystem`	`getFS()` Lazy initialization of `FileSystem` object using the `Configuration` provided in the constructor.
`org.apache.hadoop.fs.Path`	`getMaprTablePath(byte[] tableName)` Returns translated path according to the configured mapping
`static org.apache.hadoop.fs.Path`	`getMaprTablePath(org.apache.hadoop.conf.Configuration conf, java.lang.String tableName)`
`org.apache.hadoop.fs.Path`	`getMaprTablePath(java.lang.String tableName)` Returns translated path according to the configured mapping.
`boolean`	`isMapRClientInstalled()`
`boolean`	`isMapRDefault()`
`boolean`	`isMapRTable(byte[] tableName)` Tests if `tableName` should be treated as MapR table
`static boolean`	`isMapRTable(org.apache.hadoop.conf.Configuration conf, java.lang.String tableName)`
`boolean`	`isMapRTable(java.lang.String tableName)` Tests if `tableName` should be treated as MapR table
`protected org.apache.hadoop.fs.Path`	`makePath(java.lang.String parent, java.lang.String table)` Constructs absolute table path from the parent and the table name.
`void`	`setClusterType(org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules.ClusterType ctype)`
`java.lang.String`	`toString()`

Methods inherited from class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules
isInHBaseService, isMapRTable, setInHBaseService

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - MAPR_ENGINE
```
public static final java.lang.String MAPR_ENGINE
```
    See Also:
    
    Constant Field Values
  - HBASE_ENGINE
```
public static final java.lang.String HBASE_ENGINE
```
    See Also:
    
    Constant Field Values
  - HBASE_TABLE_NAMESPACE_MAPPINGS
```
public static final java.lang.String HBASE_TABLE_NAMESPACE_MAPPINGS
```
    See Also:
    
    Constant Field Values
  - HBASE_PREFIX_PATH
```
public static final org.apache.hadoop.fs.Path HBASE_PREFIX_PATH
```
- Constructor Detail
  - MapRTableMappingRules
```
public MapRTableMappingRules(org.apache.hadoop.conf.Configuration conf)
```
    Creates a table mapping rule object based on the value of 'hbase.table.namespace.mappings' parameter in the conf.
    The class maintains a global HashMap of mapping rules string and its compiled form. If the current mapping rule is not found in the map, it is compiled and put in the hash-map.
    
    Parameters:
    
    conf -
- Method Detail
  - isMapRDefault
```
public boolean isMapRDefault()
```
    Overrides:
    
    isMapRDefault in class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules
  - isMapRClientInstalled
```
public boolean isMapRClientInstalled()
```
    Overrides:
    
    isMapRClientInstalled in class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules
  - setClusterType
```
public void setClusterType(org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules.ClusterType ctype)
```
    Overrides:
    
    setClusterType in class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules
  - getClusterType
```
public org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules.ClusterType getClusterType()
```
    Overrides:
    
    getClusterType in class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules
  - isMapRTable
```
public boolean isMapRTable(byte[] tableName)
```
    Tests if tableName should be treated as MapR table
    
    Overrides:
    
    isMapRTable in class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules
    
    Parameters:
    
    conf -
    
    tableName -
    
    Returns:
    
    true if the table is determined to be a MapR table.
    
    Throws:
    
    java.lang.IllegalArgumentException - If the passed tableName is null
  - isMapRTable
```
public boolean isMapRTable(java.lang.String tableName)
```
    Tests if tableName should be treated as MapR table
    
    Overrides:
    
    isMapRTable in class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules
    
    Parameters:
    
    conf -
    
    tableName -
    
    Returns:
    
    true if the table is determined to be a MapR table.
    
    Throws:
    
    java.lang.IllegalArgumentException - If the passed tableName is null
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - getMaprTablePath
```
public org.apache.hadoop.fs.Path getMaprTablePath(byte[] tableName)
```
    Returns translated path according to the configured mapping
    
    Overrides:
    
    getMaprTablePath in class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules
    
    Parameters:
    
    conf - Hadoop Configuration instance
    
    tableName - Absolute or relative table name
    
    Returns:
    
    Translated absolute path if the table is a MapR table, null otherwise
  - getMaprTablePath
```
public org.apache.hadoop.fs.Path getMaprTablePath(java.lang.String tableName)
```
    Returns translated path according to the configured mapping. See MapRTableMappingRules
    
    Overrides:
    
    getMaprTablePath in class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules
    
    Parameters:
    
    tableName - Absolute or relative table name
    
    Returns:
    
    Translated absolute path if the table is a MapR table, null otherwise
  - makePath
```
protected org.apache.hadoop.fs.Path makePath(java.lang.String parent,
                                             java.lang.String table)
```
    Constructs absolute table path from the parent and the table name.
    1. If the parent does not end with '/', table name is ignored else table name is appended to parent.
    2. If parent does not start with '/', user's home directory is prefixed to the resultant path.
    Parameters:
    
    parent -
    
    table -
    
    Returns:
  - getFS
```
protected org.apache.hadoop.fs.FileSystem getFS()
```
    Lazy initialization of FileSystem object using the Configuration provided in the constructor. This code will not get executed if there is no rule with relative path.
    
    Returns:
  - isMapRTable
```
public static boolean isMapRTable(org.apache.hadoop.conf.Configuration conf,
                                  java.lang.String tableName)
```
  - getMaprTablePath
```
public static org.apache.hadoop.fs.Path getMaprTablePath(org.apache.hadoop.conf.Configuration conf,
                                                         java.lang.String tableName)
```
  - getDefaultTablePath
```
public org.apache.hadoop.fs.Path getDefaultTablePath()
```
    Overrides:
    
    getDefaultTablePath in class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules

Class MapRTableMappingRules

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules

Field Summary

Fields inherited from class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules

Constructor Summary

Method Summary

Methods inherited from class org.apache.hadoop.hbase.client.mapr.BaseTableMappingRules

Methods inherited from class java.lang.Object

Field Detail

MAPR_ENGINE

HBASE_ENGINE

HBASE_TABLE_NAMESPACE_MAPPINGS

HBASE_PREFIX_PATH

Constructor Detail

MapRTableMappingRules

Method Detail

isMapRDefault

isMapRClientInstalled

setClusterType

getClusterType

isMapRTable

isMapRTable

toString

getMaprTablePath

getMaprTablePath

makePath

getFS

isMapRTable

getMaprTablePath

getDefaultTablePath