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  1. Percona Toolkit
  2. PT-1189

LP #1262705: pt-table-checksum updates percona.checksum inconsistently

    Details

    • Type: Bug
    • Status: Open
    • Priority: Low
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: None
    • Component/s: None

      Description

      **Reported in Launchpad by Aleksandr Kuzminsky last update 11-11-2014 06:34:17

      pt-table-checksum does two basic operations:

      1. "UPDATE $repl_table SET chunk_time = ?, master_crc = ?, master_cnt = ? "
      2. "REPLACE INTO $repl_table ... this_cnt, this_crc'

      i.e. the first sets master_* fields and the second - this_* fields.

      Due to a fact that these two are done as separate transactions for short period of time the row on a slave is inconsistent.
      master_* fields are set, but this_* are not yet.

      This may cause false positive triggers of monitoring software.

      As a solution UPDATE and REPLACE may be wrapped into BEGIN/COMMIT, so the change of a row on a slave is atomic.

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              • Assignee:
                Unassigned
                Reporter:
                lpjirasync lpjirasync (Inactive)
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                • Created:
                  Updated: