BufferedMutator (Apache HBase 2.1.0-cdh6.3.2 API)

All Superinterfaces:

AutoCloseable, Closeable

All Known Implementing Classes:

BufferedMutatorImpl
```
@InterfaceAudience.Public
public interface BufferedMutator
extends Closeable
```
Used to communicate with a single HBase table similar to Table but meant for batched, asynchronous puts. Obtain an instance from a Connection and call close() afterwards. Customizations can be applied to the BufferedMutator via the BufferedMutatorParams.

Exception handling with asynchronously via the BufferedMutator.ExceptionListener. The default implementation is to throw the exception upon receipt. This behavior can be overridden with a custom implementation, provided as a parameter with BufferedMutatorParams.listener(BufferedMutator.ExceptionListener).

Map/Reduce jobs are good use cases for using BufferedMutator. Map/reduce jobs benefit from batching, but have no natural flush point. BufferedMutator receives the puts from the M/R job and will batch puts based on some heuristic, such as the accumulated size of the puts, and submit batches of puts asynchronously so that the M/R logic can continue without interruption.

BufferedMutator can also be used on more exotic circumstances. Map/Reduce batch jobs will have a single BufferedMutator per thread. A single BufferedMutator can also be effectively used in high volume online systems to batch puts, with the caveat that extreme circumstances, such as JVM or machine failure, may cause some data loss.

NOTE: This class replaces the functionality that used to be available via HTable#setAutoFlush(boolean) set to false.

See also the BufferedMutatorExample in the hbase-examples module.

Since:

1.0.0

See Also:

ConnectionFactory, Connection

Nested Class Summary

Nested Classes
Modifier and Type Interface and Description

static interface BufferedMutator.ExceptionListener
Listens for asynchronous exceptions on a BufferedMutator.

Nested Classes
Modifier and Type	Interface and Description
`static interface`	`BufferedMutator.ExceptionListener` Listens for asynchronous exceptions on a `BufferedMutator`.

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`CLASSNAME_KEY` Key to use setting non-default BufferedMutator implementation in Configuration.
`static long`	`MIN_WRITE_BUFFER_PERIODIC_FLUSH_TIMERTICK_MS` Having the timer tick run more often that once every 100ms is needless and will probably cause too many timer events firing having a negative impact on performance.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`void`	`close()` Performs a `flush()` and releases any resources held.
`default void`	`disableWriteBufferPeriodicFlush()` Disable periodic flushing of the write buffer.
`void`	`flush()` Executes all the buffered, asynchronous `Mutation` operations and waits until they are done.
`org.apache.hadoop.conf.Configuration`	`getConfiguration()` Returns the `Configuration` object used by this instance.
`TableName`	`getName()` Gets the fully qualified table name instance of the table that this BufferedMutator writes to.
`default long`	`getWriteBufferPeriodicFlushTimeoutMs()` Returns the current periodic flush timeout value in milliseconds.
`default long`	`getWriteBufferPeriodicFlushTimerTickMs()` Returns the current periodic flush timertick interval in milliseconds.
`long`	`getWriteBufferSize()` Returns the maximum size in bytes of the write buffer for this HTable.
`void`	`mutate(List<? extends Mutation> mutations)` Send some `Mutation`s to the table.
`void`	`mutate(Mutation mutation)` Sends a `Mutation` to the table.
`void`	`setOperationTimeout(int timeout)` Set operation timeout for this mutator instance
`void`	`setRpcTimeout(int timeout)` Set rpc timeout for this mutator instance
`default void`	`setWriteBufferPeriodicFlush(long timeoutMs)` Sets the maximum time before the buffer is automatically flushed checking once per second.
`default void`	`setWriteBufferPeriodicFlush(long timeoutMs, long timerTickMs)` Sets the maximum time before the buffer is automatically flushed.

- Field Detail
  - CLASSNAME_KEY
```
static final String CLASSNAME_KEY
```
    Key to use setting non-default BufferedMutator implementation in Configuration.
    
    See Also:
    
    Constant Field Values
  - MIN_WRITE_BUFFER_PERIODIC_FLUSH_TIMERTICK_MS
```
static final long MIN_WRITE_BUFFER_PERIODIC_FLUSH_TIMERTICK_MS
```
    Having the timer tick run more often that once every 100ms is needless and will probably cause too many timer events firing having a negative impact on performance.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - getName
```
TableName getName()
```
    Gets the fully qualified table name instance of the table that this BufferedMutator writes to.
  - getConfiguration
```
org.apache.hadoop.conf.Configuration getConfiguration()
```
    Returns the Configuration object used by this instance.
    The reference returned is not a copy, so any change made to it will affect this instance.
  - mutate
```
void mutate(Mutation mutation)
     throws IOException
```
    Sends a Mutation to the table. The mutations will be buffered and sent over the wire as part of a batch. Currently only supports Put and Delete mutations.
    
    Parameters:
    
    mutation - The data to send.
    
    Throws:
    
    IOException - if a remote or network exception occurs.
  - mutate
```
void mutate(List<? extends Mutation> mutations)
     throws IOException
```
    Send some Mutations to the table. The mutations will be buffered and sent over the wire as part of a batch. There is no guarantee of sending entire content of mutations in a single batch; it will be broken up according to the write buffer capacity.
    
    Parameters:
    
    mutations - The data to send.
    
    Throws:
    
    IOException - if a remote or network exception occurs.
  - close
```
void close()
    throws IOException
```
    Performs a flush() and releases any resources held.
    
    Specified by:
    
    close in interface AutoCloseable
    
    Specified by:
    
    close in interface Closeable
    
    Throws:
    
    IOException - if a remote or network exception occurs.
  - flush
```
void flush()
    throws IOException
```
    Executes all the buffered, asynchronous Mutation operations and waits until they are done.
    
    Throws:
    
    IOException - if a remote or network exception occurs.
  - setWriteBufferPeriodicFlush
```
default void setWriteBufferPeriodicFlush(long timeoutMs)
```
    Sets the maximum time before the buffer is automatically flushed checking once per second.
    
    Parameters:
    
    timeoutMs - The maximum number of milliseconds how long records may be buffered before they are flushed. Set to 0 to disable.
  - setWriteBufferPeriodicFlush
```
default void setWriteBufferPeriodicFlush(long timeoutMs,
                                         long timerTickMs)
```
    Sets the maximum time before the buffer is automatically flushed.
    
    Parameters:
    
    timeoutMs - The maximum number of milliseconds how long records may be buffered before they are flushed. Set to 0 to disable.
    
    timerTickMs - The number of milliseconds between each check if the timeout has been exceeded. Must be 100ms (as defined in MIN_WRITE_BUFFER_PERIODIC_FLUSH_TIMERTICK_MS) or larger to avoid performance problems.
  - disableWriteBufferPeriodicFlush
```
default void disableWriteBufferPeriodicFlush()
```
    Disable periodic flushing of the write buffer.
  - getWriteBufferPeriodicFlushTimeoutMs
```
default long getWriteBufferPeriodicFlushTimeoutMs()
```
    Returns the current periodic flush timeout value in milliseconds.
    
    Returns:
    
    The maximum number of milliseconds how long records may be buffered before they are flushed. The value 0 means this is disabled.
  - getWriteBufferPeriodicFlushTimerTickMs
```
default long getWriteBufferPeriodicFlushTimerTickMs()
```
    Returns the current periodic flush timertick interval in milliseconds.
    
    Returns:
    
    The number of milliseconds between each check if the timeout has been exceeded. This value only has a real meaning if the timeout has been set to > 0
  - getWriteBufferSize
```
long getWriteBufferSize()
```
    Returns the maximum size in bytes of the write buffer for this HTable.
    The default value comes from the configuration parameter hbase.client.write.buffer.
    
    Returns:
    
    The size of the write buffer in bytes.
  - setRpcTimeout
```
void setRpcTimeout(int timeout)
```
    Set rpc timeout for this mutator instance
  - setOperationTimeout
```
void setOperationTimeout(int timeout)
```
    Set operation timeout for this mutator instance

Interface BufferedMutator

Nested Class Summary

Field Summary

Method Summary

Field Detail

CLASSNAME_KEY

MIN_WRITE_BUFFER_PERIODIC_FLUSH_TIMERTICK_MS

Method Detail

getName

getConfiguration

mutate

mutate

close

flush

setWriteBufferPeriodicFlush

setWriteBufferPeriodicFlush

disableWriteBufferPeriodicFlush

getWriteBufferPeriodicFlushTimeoutMs

getWriteBufferPeriodicFlushTimerTickMs

getWriteBufferSize

setRpcTimeout

setOperationTimeout