An under-documented feature in Cloudera Manager is the HBase Check HFile Version. When upgrading from CDH 4.7 to CDH 5.0, I ran across the instructions that the HBase upgrade will not be successful if there are any HFiles with version 1 present. Run “Check HFile Version” from the HBase service Actions menu to ensure that HBase is ready for the upgrade.
After a check if HFiles with v1 are present, and “Process (###) has reached expected state”, you are looking for the message that No files with v1 were found and HBase can be upgraded. Otherwise HBase regions will have to be compacted. I’ll post more on that later.
In Stderr, look for the following:
INFO util.HFileV1Detector: Count of HFileV1: 0 INFO util.HFileV1Detector: Count of corrupted files: 0 INFO util.HFileV1Detector: Count of Regions with HFileV1: 0
