BlockManager#processMisReplicatesAsync is the daemon thread running inside namenode to handle miserplicated blocks. As shown below, it has a trace log for each of the block in the cluster being processed (10000 blocks per iteration after sleep 10s).
However, it is not very useful as dumping every block in the cluster will overwhelm the namenode log without much useful information assuming the majority of the blocks are not over/under replicated. This ticket is opened to improve the log for easy troubleshooting of block replication related issues by:
1) add debug log for blocks that get under/over replicated result during processMisReplicatedBlock()
2) or change to trace log for only blocks that get non-OK result during processMisReplicatedBlock()