Percona Toolkit moved to https://jira.percona.com/projects/PT

pt-table-checksum char-chunking may cause uninitialized value and division by zero errors

Bug #821714 reported by Daniel Nichter
16
This bug affects 3 people
Affects Status Importance Assigned to Milestone
Percona Toolkit moved to https://jira.percona.com/projects/PT
Won't Fix
Medium
Unassigned

Bug Description

Imported from http://code.google.com/p/maatkit/issues/detail?id=1286

Basically, char chunking will cause problems if the range of char isn't wide. E.g. if everything starts with "Foo" then you can expect problems. Problems occur even if the range is very small, like a to m. It depends on the decimal conversion of characters, using a different base for counting, etc. In essence: char chunking needs work because it breaks unless the case is ideal.

Revision history for this message
Baron Schwartz (baron-xaprb) wrote : Re: [Bug 821714] [NEW] pt-table-checksum char-chunking may cause uninitialized value and division by zero errors

I would suggest that we remove chunking completely, and mark this as WontFix.

Revision history for this message
Joe (joegrasse) wrote :

I have attached a patch for this issue. It also includes a fix for an issue I discovered when the base_count function calculates the highest power (caused by rounding errors).

Revision history for this message
Baron Schwartz (baron-xaprb) wrote :

Joe,

Thanks. This tool is being completely rewritten and we're abandoning chunking in favor of nibbling (same effect, different mechanism). This won't be an issue as a result so I will WontFix this issue.

Changed in percona-toolkit:
status: New → Won't Fix
Revision history for this message
Dave Juntgen (djuntgen) wrote :

Baron - when will the new tool be completed or can you push a version that removes the chunk char check?

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Dave Juntgen (djuntgen) wrote :

OR - would it be best to change the algorithm to nibble?

Revision history for this message
Baron Schwartz (baron-xaprb) wrote :

You read my/our minds. The new version of the tool just nibbles everything. You can get it from source: http://bazaar.launchpad.net/~percona-toolkit-dev/percona-toolkit/pt-table-checksum-2.0/

Revision history for this message
Shahriyar Rzayev (rzayev-sehriyar) wrote :

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PT-410

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