apache flume example - Wikitechy

What are the channel types in Flume and Which channel type is faster ?

Editor — Sun, 11 Jul 2021 16:10:38 +0000

Channels in Flume

It stores events; events are delivered to the channel by means of sources operating within the agent.
An event remains in the channel until a sink removes it for further transport.

There are three different built in channels in Flume –

MEMORY Channel – Events are study from the source into memory and passed to the sink.
JDBC Channel – It stores the events in an embedded Derby database.
FILE Channel – It writes the contents to a file on the file system after reading the event from a source. The file is erased only after the contents are successfully delivered to the sink.

MEMORY Channel – It is the fastest channel among the three however has the risk of data loss. The channel that you choose totally depends on the nature of the big data application and the value of each event.

What is Channel Selectors ?

Editor — Sun, 11 Jul 2021 15:50:47 +0000

Channel Selectors

- Channel selectors control and dividing the events and allocating a specific channel. They are default or replicated channel selectors.

Replicated channel selectors can duplicate the information in multiple or all channels. Multiplexing channel selectors used to divide and aggregate the data based on the events header data.
It means based on sinks destination, the event aggregate into the specific sink.
Example: One sink associated with hadoop, another with S3 another with Hbase, at that time, Multiplexing channel selectors can divide the events and flow to the specific sink.

Learn Flume – Flume tutorial – what are channel selectors – Flume examples – Flume programs

Overview and Architecture, a source can write at least with one or more channels.
This is reason the property is plural channels instead of channel.
There are two ways multiple channels can be handled. The event can be written to every channel or to only one channel, based on some Flume header value.
The internal mechanism for this in Flume is known as channel selector.
The selector for any channel can be determined using the selector.type property.

All selector-specific properties start with the typical Source prefix: the agent name, keyword sources, and source name:

agent.sources.s1.selector.type=replicating

What is Interceptor in Apache Flume ?

Editor — Sun, 11 Jul 2021 15:29:39 +0000

Interceptor in Apache Flume

Apache Flume offers interceptors as a method of modifying records as they have a Flume channel.
Interceptors are used to filter the events between source and channel, channel and sink. These channels will filter un-necessary or targeted log files.

Interceptors are a part of Flume’s extensibility model. They permit events to be inspected as they pass between a source and a channel, and also the developer is liberated to modify or drop events as needed. Interceptors in the chain along to create a pipeline process.

What is Apache flume ?

Editor — Sun, 11 Jul 2021 15:17:38 +0000

Apache flume

Apache Flume is a reliable, distributed and accessible service for efficiently aggregating, collecting, and moving huge amounts of log data.
It has an easy and flexible design based on streaming data flows. It’s robust and fault tolerant with tunable reliability mechanisms and recovery mechanisms.
It uses an easy extensible data model that enables for on-line analytic application.

Learn Flume – Flume tutorial – apache flume – Flume examples – Flume programs

Flume defines a simple pipeline structure with three roles:

1. Source
2. Channel
3. Sinks

Sources define where data comes from, e.g. a file, a message queue (Kafka,JMS).
Channels are pipes connecting sources with sinks.
Sinks are the destination of the data pipelined from sources.