[HBASE-4516] HFile-level load tester with compaction and random-read workloads

• Type: Test
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.94.0
• Assignee: Mikhail Gryzykhin
• Reporter: Mikhail Gryzykhin
• Created: 29/Sep/11 21:32
• Updated: 12/Oct/12 05:35
• Resolved: 10/Feb/12 02:45

Description

This is a load testing tool for HFile implementations, which supports two workloads:

• Compactions (merge the input HFiles). A special case of this is only one input, which allows to do HFile format conversions.
• Random reads. Launches the specified number of threads that do seeks and short scans on randomly generated keys.

The original purpose of this tool was to ensure that HFile format v2 did not introduce performance regressions.

Keys for the read workload are generated randomly between the first and the last key of the HFile. At each position, instead of precisely calculating the correct probability for every byte value b, we select a uniformly random byte between in the allowed [low, high] range. In addition, there is a heuristic that determines the positions at which the key has hex characters, and the random key contains hex characters at those positions as well.

Example output for the random read workload:
Time: 120 sec, seek/sec: 8290, kv/sec: 30351, kv bytes/sec: 91868121, blk/sec: 10147, unique keys: 232779