We were seeing the same issue when our HDFS instance was overloaded and taking over a second to respond. I assume if whatever backend is down the collector will die and need to be restarted when it becomes available again? Doesn't seem very reliable 

On Wed, Oct 19, 2011 at 8:13 AM, Ralph Goers <ralph.goers@dslextreme.com> wrote:
We saw this problem when it was taking more than 1 second for a response from writing to Cassandra (our back end).  A single long response will kill the collector.  We had to revert back to the version of Flume that uses syncrhonization instead of read/write locking to get around this.


On Oct 18, 2011, at 1:55 PM, AD wrote:

> Hello,
>  My collector keeps dying with the following error, is this a known issue? Any idea how to prevent or find out what is causing it ?  is format("%{nanos}" an issue ?
> 2011-10-17 23:16:33,957 INFO com.cloudera.flume.core.connector.DirectDriver: Connector logicalNode flume1-18 exited with error: null
> java.lang.InterruptedException
>       at java.util.concurrent.locks.AbstractQueuedSynchronizer.tryAcquireNanos(AbstractQueuedSynchronizer.java:1246)
>       at java.util.concurrent.locks.ReentrantReadWriteLock$WriteLock.tryLock(ReentrantReadWriteLock.java:1009)
>       at com.cloudera.flume.handlers.rolling.RollSink.close(RollSink.java:296)
>       at com.cloudera.flume.core.EventSinkDecorator.close(EventSinkDecorator.java:67)
>       at com.cloudera.flume.core.EventSinkDecorator.close(EventSinkDecorator.java:67)
> source:  collectorSource("35853")
> sink:  regexAll("^([0-9.]+)\\s\\[([0-9a-zA-z\\/: -]+)\\]\\s([A-Z]+)\\s([a-zA-Z0-9.:]+)\\s\"([^\\s]+)\"\\s([0-9]+)\\s([0-9]+)\\s\"([^\\s]+)\"\\s\"([a-zA-Z0-9\\/()_ -;]+)\"\\s(hit|miss)\\s([0-9.]+)","hbase_remote_host","hbase_request_date","hbase_request_method","hbase_request_host","hbase_request_url","hbase_response_status","hbase_response_bytes","hbase_referrer","hbase_user_agent","hbase_cache_hitmiss","hbase_origin_firstbyte") format("%{nanos}:") split(":", 0, "hbase_") format("%{node}:") split(":",0,"hbase_node") digest("MD5","hbase_md5") collector(10000) { attr2hbase("apache_logs","f1","","hbase_") }


Cameron Gandevia