[KUDU-2615] Add more tools for dealing with the WAL

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.8.0
• Component/s: log
• Assignee: William Berkeley
• Reporter: William Berkeley
• Created: 26/Oct/18 18:38
• Updated: 25/Jul/19 22:28

Description

There's only one tool for dealing with WALs, the dump tool, which lets you see what's in the WAL by reading it like a Kudu server would and then dumping it as debug strings.

We could probably use a few more, though. This JIRA serves as a tracking JIRA for new WAL tools and as a parent JIRA for some existing WAL tool JIRAs.

Tools we could add or enhancements we could make:

• 'kudu wal dump --debug' with batch offsets. This would have been useful to me a couple times when I've done WAL surgery.
• 'kudu wal dump repair' maybe with truncate capability (KUDU-1503) or the capability to 'punch out' an entry.
• A 'kudu wal compare' tool that can compare two WALs and show their differences, so the WALs of two replicas of the same tablet could be compared.
• A 'kudu wal edit' tool that can edit some kinds of wal entries-- the use case for this is editing the hostports of peers in config change operations (KUDU-2396).

Issue Links

• is a parent of: KUDU-1503 Add a WAL truncation tool
• is a parent of: KUDU-2396 Tool to edit host/port for pending config changes in the WAL after machine migration