org.apache.flume.sink
Class AvroSink

java.lang.Object
  org.apache.flume.sink.AbstractSink
      org.apache.flume.sink.AbstractRpcSink
          org.apache.flume.sink.AvroSink

All Implemented Interfaces:

Configurable, LifecycleAware, NamedComponent, Sink

public class AvroSink
extends AbstractRpcSink

A Sink implementation that can send events to an RPC server (such as Flume's AvroSource).

This sink forms one half of Flume's tiered collection support. Events sent to this sink are transported over the network to the hostname / port pair using the RPC implementation encapsulated in RpcClient. The destination is an instance of Flume's AvroSource, which allows Flume agents to forward to other Flume agents, forming a tiered collection infrastructure. Of course, nothing prevents one from using this sink to speak to other custom built infrastructure that implements the same RPC protocol.

Events are taken from the configured Channel in batches of the configured batch-size. The batch size has no theoretical limits although all events in the batch must fit in memory. Generally, larger batches are far more efficient, but introduce a slight delay (measured in millis) in delivery. The batch behavior is such that underruns (i.e. batches smaller than the configured batch size) are possible. This is a compromise made to maintain low latency of event delivery. If the channel returns a null event, meaning it is empty, the batch is immediately sent, regardless of size. Batch underruns are tracked in the metrics. Empty batches do not incur an RPC roundtrip.

Configuration options

Parameter	Description	Unit (data type)	Default
hostname	The hostname to which events should be sent.	Hostname or IP (String)	none (required)
port	The port to which events should be sent on hostname.	TCP port (int)	none (required)
batch-size	The maximum number of events to send per RPC.	events (int)	100
connect-timeout	Maximum time to wait for the first Avro handshake and RPC request	milliseconds (long)	20000
request-timeout	Maximum time to wait RPC requests after the first	milliseconds (long)	20000

Metrics

TODO

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flume.Sink

Sink.Status

Constructor Summary

AvroSink()

Method Summary

protected RpcClient

initializeRpcClient(Properties props) Returns a new RpcClient instance configured using the given Properties object.

Methods inherited from class org.apache.flume.sink.AbstractRpcSink

configure, process, start, stop, toString

Methods inherited from class org.apache.flume.sink.AbstractSink

getChannel, getLifecycleState, getName, setChannel, setName

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

AvroSink

public AvroSink()

Method Detail

initializeRpcClient

protected RpcClient initializeRpcClient(Properties props)

Description copied from class: AbstractRpcSink

Returns a new RpcClient instance configured using the given Properties object. This method is called whenever a new connection needs to be created to the next hop.

Specified by:

initializeRpcClient in class AbstractRpcSink

Returns: