Maybe post your entire config?
On Tue, Feb 19, 2013 at 5:35 PM, Noel Duffy <[email protected]>wrote: > In my tests I set up two Flume agents connected to two different HDFS > clusters. The configuration of both Flume agents is identical. They read > events from the same RabbitMQ server. In my test, both agent hosts wrote > the event to their respective HDFS servers using hdfsSink-2, but I expected > the failover sinkgroup configuration would mean only one host would write > the event. In other words, I thought that a failover sinkgroup could be > configured to have sinks on different hosts but that only one sink on one > host would actually write the event and that the other host would not do > anything. > > All the examples in the documentation have all sinks in a sinkgroup on a > single host. I want to have the sinks on different hosts. I've seen a > number of assertions online that this can be done, but so far, I've not > seen any examples of how to actually configure it. > > From: Jeff Lord [mailto:[email protected]] > Sent: Wednesday, 20 February 2013 2:17 p.m. > To: [email protected] > Subject: Re: Architecting Flume for failover > > Noel, > > What test did you perform? > Did you stop sink-2? > Currently you have set a higher priority for sink-2 so it will be the > default sink so long as it is up and running. > > -Jeff > > http://flume.apache.org/FlumeUserGuide.html#failover-sink-processor > > On Tue, Feb 19, 2013 at 5:03 PM, Noel Duffy <[email protected]> > wrote: > The ip addresses 10.20.30.81 and 10.20.30.119 are the addresses of the > Flume agents. The first agent is on 10.20.30.81, the second on > 10.20.30.119. The idea was to have two sinks on different hosts and to > configure Flume to failover to the second host if the first host should > disappear. Although the documentation does not say so explicitly, I have > read posts online which say that such a configuration is possible. I am > running Flume-ng 1.2.0. > > It may be that I am approaching this problem in the wrong way. We need to > have Flume reading events from RabbitMQ and writing them to HDFS. We want > to have two different hosts running Flume so that if one dies for any > reason, the other would take over and no events should be lost or delayed. > Later we may have more Flume hosts, depending on how well they cope with > the expected traffic, but for now two will suffice to prove the concept. A > load-balancing sink processor sounds like it might also be a solution, but > again, I do not see how to configure this to work across more than one host. > > > From: Hari Shreedharan [mailto:[email protected]] > Sent: Wednesday, 20 February 2013 1:31 p.m. > To: [email protected] > Subject: Re: Architecting Flume for failover > > Can you change the hdfs.path to hdfs://10.20.30.81/flume/localbrain-eventsand > hdfs:// > 10.20.30.119/flume/localbrain-events on hdfsSink-1 and hdfsSink-2 > respectively (assuming those are your namenodes)? The "bind" configuration > param does not really exist for HDFS Sink (it is only for the IPC sources). > > > Thanks > Hari > > -- > Hari Shreedharan > > On Tuesday, February 19, 2013 at 4:05 PM, Noel Duffy wrote: > If I disable the agent.sinks line, both my sinks are disabled and nothing > gets written to HDFS. The status page no longer shows me any sinks. > > From: Yogi Nerella [mailto:[email protected]] > Sent: Wednesday, 20 February 2013 12:40 p.m. > To: [email protected] > Subject: Re: Architecting Flume for failover > > Hi Noel, > > May be you are specifying both sinkgroups and sinks. > > Can you try removing the sinks. > #agent.sinks = hdfsSink-1 hdfsSink-2 > > Yogi > > > On Tue, Feb 19, 2013 at 1:32 PM, Noel Duffy <[email protected]> > wrote: > I have a Flume agent that pulls events from RabbitMQ and pushes them into > HDFS. So far so good, but now I want to have a second Flume agent on a > different host acting as a hot backup for the first agent such that the > loss of the first host running Flume would not cause any events to be lost. > In the testing I've done I've gotten two Flume agents on separate hosts to > read the same events from the RabbitMQ queue, but it's not clear to me how > to configure the sinks such that only one of the sinks actually does > something and the other does nothing. > > From reading the documentation, I supposed that a sinkgroup configured for > failover was what I needed, but the documentation examples only cover the > case where the sinks in a failover group are all on the same agent on the > same host. I've seen messages online which seem to say that sinks in a > sinkgroup can be on different hosts, but I can find no clear explanation of > how to configure such a sinkgroup. How would sinks on different hosts > communicate with one another? Would the sinks in the sinkgroup have to use > a JDBC channel? Would the sinks have to be non-terminal sinks, like Avro? > > In my testing I set up two agents on different hosts and configured a > sinkgroup containing two sinks, both HDFS sinks. > > agent.sinkgroups = sinkgroup1 > agent.sinkgroups.sinkgroup1.sinks = hdfsSink-1 hdfsSink-2 > agent.sinkgroups.sinkgroup1.processor.priority.hdfsSink-1 = 5 > agent.sinkgroups.sinkgroup1.processor.priority.hdfsSink-2 = 10 > agent.sinkgroups.sinkgroup1.processor.type=failover > > agent.sinks = hdfsSink-1 hdfsSink-2 > agent.sinks.hdfsSink-1.type = hdfs > agent.sinks.hdfsSink-1.bind = 10.20.30.81 > agent.sinks.hdfsSink-1.channel = fileChannel-1 > agent.sinks.hdfsSink-1.hdfs.path = /flume/localbrain-events > agent.sinks.hdfsSink-1.hdfs.filePrefix = lb-events > agent.sinks.hdfsSink-1.hdfs.round = false > agent.sinks.hdfsSink-1.hdfs.rollCount=50 > agent.sinks.hdfsSink-1.hdfs.fileType=SequenceFile > agent.sinks.hdfsSink-1.hdfs.writeFormat=Text > agent.sinks.hdfsSink-1.hdfs.codeC = lzo > agent.sinks.hdfsSink-1.hdfs.rollInterval=30 > agent.sinks.hdfsSink-1.hdfs.rollSize=0 > agent.sinks.hdfsSink-1.hdfs.batchSize=1 > > agent.sinks.hdfsSink-2.bind = 10.20.30.119 > agent.sinks.hdfsSink-2.type = hdfs > agent.sinks.hdfsSink-2.channel = fileChannel-1 > agent.sinks.hdfsSink-2.hdfs.path = /flume/localbrain-events > agent.sinks.hdfsSink-2.hdfs.filePrefix = lb-events > agent.sinks.hdfsSink-2.hdfs.round = false > agent.sinks.hdfsSink-2.hdfs.rollCount=50 > agent.sinks.hdfsSink-2.hdfs.fileType=SequenceFile > agent.sinks.hdfsSink-2.hdfs.writeFormat=Text > agent.sinks.hdfsSink-2.hdfs.codeC = lzo > agent.sinks.hdfsSink-2.hdfs.rollInterval=30 > agent.sinks.hdfsSink-2.hdfs.rollSize=0 > agent.sinks.hdfsSink-2.hdfs.batchSize=1 > > However, this does not achieve the failover I hoped for. The sink > hdfsSink-2 on both agents writes the events to HDFS. The agents are not > communicating, so the binding of the sink to an ip address is not doing > anything. > >
