Moving them in 10% at a time would be a good plan. You'll want to make sure that they are on the same filesystem, just in a different directory, so the move isn't copying across filesystems, just changing inodes. Going forward, it would be recommended to add a flume channel trigger, to alert you when the channel starts filling up, if your downstream agent isn't accepting events. -pd ... View more

No, if you only have one sink, you would have one file (assuming you don't use header variable buckets). The sink will consume from all three partitions and may deliver those in one batch to one file. -pd ... View more

What version of CDH are you using? In newer versions it displays a warning, but still allows you to save the changes without a source. -pd ... View more

The snapshots are part of the indexes, representing a point in time list of the segments in the index. When you perform the backup, the metadata (information about the cluster) and the snapshot specified indicate s which set of index files to be backup up/copied to the destination hdfs directory (as specified in the <backup> section of the source solr.xml) This blog walks through the process https://blog.cloudera.com/blog/2017/05/how-to-backup-and-disaster-recovery-for-apache-solr-part-i/ When you run the --prepare-snapshot-export, it creates a copy of the metadata, and a copylisting of all the files that will be copied by the distcp command, to the remote cluster. Then, when you execute the snapshot export, the distcp command will copy those files to the remote cluster. The -b on the restore command is just the name of the directory (represented by the snapshot name) that was created and copied by distcp. -pd ... View more

Morphlines would be the preferred way to selectively choose the data that will be passing through the source to the sink. you can use the morphline removeFields command [1] to selectively drop the fields you don't want. If you need to review what is happening with the data you can turn on morphline TRACE by adding the following to the flume logging safety valve: log4j.logger.org.kitesdk.morphline=TRACE   -pd   [1] http://kitesdk.org/docs/1.1.0/morphlines/morphlines-reference-guide.html#removeFields ... View more

What is your channel size in the flume metrics page reported as? Is it decreasing? flume keeps at least the two most recent log files in the flume file channel at all times, regardless of whether it is fully drained or not. The best is to review the channel size in the flume metrics page, or on the channel size charts. -pd ... View more

FLUME-3027 has been backported to CDH5.11.0 and above, so if you are able to upgrade, it would prevent the issue of offsets bouncing back and forward. One thing you may want to consider, if you are getting rebalances, it may be because it is taking too long to deliver by your sink, before polling kafka again. You may want to consider lowering your sink batch size in order to deliver and ack the messages in a timely fashion. Additionally, if you upgrade to CDH5.14 or higher, the flume kafka client is 0.10.2, and you would be able to set max.poll.records to match the batchSize you are using for the flume sink. Additionally, you could increase the max.poll.interval.ms, which is decoupled from the session.timeout.ms in 0.10.0 and above. This would prevent the rebalancing from occurring since the client would still heartbeat without having to do a poll to pull more records before session.timeout.ms expires. -pd ... View more