[HBASE-3968] HLog Pretty Printer

• Type: New Feature
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.90.4
• Component/s: io, regionserver, util
• Labels: hbase
• Hadoop Flags: Reviewed

Release Note

Implementation of a Pretty Printer for HLogs. Can be accessed with the Java API or with a command line interface, which replaces HLog --dump functionality. Can output to a human-readable pretty format, or to a JSON list for easy parsing in diagnostic scripts. Can also filter by region, row, and/or sequence id. See command line usage (HLog --dump -h) and the javadocs for more detail on these features.

• Assignee: Riley Patterson
• Reporter: Nicolas Spiegelberg
• Created: 09/Jun/11 01:03
• Updated: 20/Nov/15 11:53
• Resolved: 01/Jul/11 21:51

Description

We currently have a rudimentary way to print HLog data, but it is limited and currently prints key-only information. We need extend this functionality, similar to how we developed HFile's pretty printer. Ideas for functionality:

• filter by sequence_id
• filter by row / region
• option to print values in addition to key info
• option to print output in JSON format (so scripts can easily parse for analysis)

Issue Links

• is depended upon by: HBASE-4040 Make HFilePrettyPrinter programmatically invocable and add JSON output
• is related to: HBASE-4040 Make HFilePrettyPrinter programmatically invocable and add JSON output
• is required by: HBASE-4038 Hot Region : Write Diagnosis
• relates to: HBASE-2383 Replace JSON-licensed json dependencies