Junegunn Choi created HBASE-15569: ------------------------------------- Summary: Make Bytes.toStringBinary faster Key: HBASE-15569 URL: https://issues.apache.org/jira/browse/HBASE-15569 Project: HBase Issue Type: Improvement Components: Performance Reporter: Junegunn Choi Assignee: Junegunn Choi Priority: Minor
Bytes.toStringBinary is quite expensive due to its use of {{String.format}}. It seems to me that {{String.format}} is overkill for the purpose and I could actually make the function up to 45-times faster by replacing the part with a simpler hand-crafted code. This is probably a non-issue for HBase server as the function is not used in performance-sensitive contexts but I figured it wouldn't hurt to make it faster as it's widely used in builtin tools - Shell, {{HFilePrettyPrinter}} with {{-p}} option, etc. - and it can be used in clients. h4. Background: We have [an HBase monitoring tool|https://github.com/kakao/hbase-region-inspector] that periodically collects the information of the regions and it calls {{Bytes.toStringBinary}} during the process to make some information suitable for display. Profiling revealed that a large portion of the processing time was spent in {{String.format}}. h4. Micro-benchmark: {code} byte[] bytes = new byte[256]; for (int i = 0; i < bytes.length; ++i) { // Mixture of printable and non-printable characters. // Maximal performance gain (45x) is observed when the array is solely // composed of non-printable characters. bytes[i] = (byte) i; } long started = System.nanoTime(); for (int i = 0; i < 1000000; ++i) { Bytes.toStringBinary(bytes); } System.out.println(TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - started)); {code} - Without the patch: 134176 ms - With the patch: 3890 ms I made sure that the new version returns the same value as before and simplified the check for non-printable characters. -- This message was sent by Atlassian JIRA (v6.3.4#6332)