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Flume >> mail # user >> Failover Processor + Load Balanced Processor?


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Chris Neal 2012-08-17, 15:59
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Arvind Prabhakar 2012-08-17, 17:01
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Juhani Connolly 2012-09-04, 10:39
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Re: Failover Processor + Load Balanced Processor?
Since there was no response to this, I set up a separate ticket  at
https://issues.apache.org/jira/browse/FLUME-1541 and implemented it as a
SinkSelector for the LoadBalancingSinkProcessor.

Review can be found at https://reviews.apache.org/r/6939/

Chris: if you're interested you may want to give this a poke, see if it
fulfills your needs. The only change in configuration needed is to
change the selector type from "round_robin" to "round_robin_backoff"

On 09/04/2012 07:39 PM, Juhani Connolly wrote:
> I'm thinking of working on this(adding backoff semantics to the load
> balancing processor)
>
> The ticket FLUME-1488 however refers to the load balancing rpc
> client(or is it just poorly worded/unclear?). If it is in fact a
> separate ticket I'll file one for this
>
> Anyway, I was  interested in hearing thoughts on approach. I'd have
> liked to do it within the framework of the LoadBalancingSinkProcessor
> by adding a new Selector, however as it is now, it the processor
> provides no feedback to the selectors about whether sinks are working
> or not, so this can't work.
>
> This leaves two choices: write a new SinkProcessor or modify the
> SinkSelector interface to give it a couple of callbacks that the
> processor calls to inform the selector of trouble. This shouldn't
> really be a problem even if people have written their own selectors so
> long as they are extending AbstractSinkSelector which can stub the
> callbacks.
>
> Thoughts?
>
> On 08/18/2012 02:01 AM, Arvind Prabhakar wrote:
>> Hi,
>>
>> FYI - the load balancing sink processor does support simple failover
>> semantics. The way it works is that if a sink is down, it will
>> proceed to the next sink in the group until all sinks are exhausted.
>> The failover sink processor on the other hand does complex failure
>> handling and back-off such as blacklisting sinks that repeatedly fail
>> etc. The issue [1] tracks enhancing this processor to support backoff
>> semantics.
>>
>> The one issue with your configuration that I could spot by a quick
>> glance is that you are adding your active sinks to both the sink
>> groups. This does not really work and the configuration subsystem
>> simply flags the second inclusion as a problem and ignores it. By
>> design, a sink can either be on its own or in one explicit sink group.
>>
>> [1] https://issues.apache.org/jira/browse/FLUME-1488
>>
>> Regards,
>> Arvind Prabhakar
>>
>> On Fri, Aug 17, 2012 at 8:59 AM, Chris Neal <[EMAIL PROTECTED]
>> <mailto:[EMAIL PROTECTED]>> wrote:
>>
>>     Hi all.
>>
>>     The User Guide talks about the various types of Sink Processors,
>>     but doesn't say whether they can be aggregated together.  A
>>     Failover Processor that moves between 1..n sinks is great, as is
>>     a Load Balancer Processor that moves between 1..n sinks, but what
>>     is the best would be an agent that can utilize both a Failover
>>     Processor AND a Load Balancer Processor!
>>
>>     I've created a configuration which I believe supports this, and
>>     the Agent starts up and processes events, but I wanted to ping
>>     this group to make sure that this configuration is really doing
>>     what I think it is doing behind the scenes.
>>
>>     Comments?
>>
>>     # Define the sources, sinks, and channels for the agent
>>     agent.sources = avro-instance_1-source avro-instance_2-source
>>     agent.channels = memory-agent-channel
>>     agent.sinks = avro-hdfs_1-sink avro-hdfs_2-sink
>>     agent.sinkgroups = failover-sink-group lb-sink-group
>>
>>     # Bind sources to channels
>>     agent.sources.avro-instance_1-source.channels = memory-agent-channel
>>     agent.sources.avro-instance_2-source.channels = memory-agent-channel
>>
>>     # Define sink group for failover
>>     agent.sinkgroups.failover-sink-group.sinks = avro-hdfs_1-sink
>>     avro-hdfs_2-sink
>>     agent.sinkgroups.failover-sink-group.processor.type = failover
>>     agent.sinkgroups.failover-sink-group.processor.priority.avro-hdfs_1-sink
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Chris Neal 2012-09-06, 14:35
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Chris Neal 2012-08-17, 17:11
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Arvind Prabhakar 2012-08-17, 17:19
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Chris Neal 2012-08-17, 21:13