In our testing of HBase 1.3 against the current tip of branch-1 we saw a 30% slowdown in scanning scenarios.
We tracked it back to HBASE-17958 and HBASE-19863.
Both add comparisons to one of the tightest HBase has.
Avoid passing unexpected cell to ScanQueryMatcher when optimize SEEK to SKIP
java.lang.IllegalStateException: isDelete failed when SingleColumnValueFilter is used
Reseek regression related to filter SKIP hinting
GitHub Pull Request #2075
GitHub Pull Request #2081