SHOW ENGINE INNODB STATUS truncation, innodb_truncated_status_writes

Another piece of good news for MySQL 5.5 – the output of SHOW ENGINE INNODB STATUS has now been increased from 64kB, to 1MB. For those running with systems that have thousands of running transactions, or large lock outputs, it should take quite a bit more to force truncation now. :)

We also added a new status variable to track when truncation happens as well – innodb_truncated_status_writes, so you can detect this should you have automated monitoring depending on this output.

Bug#56922 for details.

7 comments

  1. That data is too important to truncate. At the very least the per-transaction output should be the last thing printed so it is the part that gets truncated. I prefer to use two commands — SHOW INNODB STATUS to print everything but the per-transaction status and SHOW INNODB TRANSACTION STATUS to print the transaction status. Of course, the per-transaction status is or will be in an IS table.

  2. Re-ordering output has been frowned upon in the past. Quite loudly by one particular person in the past if I remember right.. ;)

    It’s true that sane parsing of the output should not break, but we can’t always rely on the sane parsing bit. :(

  3. Far more significant changes have been done between major releases. But you don’t have to use these commands if that prevents the change. You can add a new command: SHOW INNODB STATUS WITHOUT LOSING CRITICAL DATA :)

  4. Personally if I had my way we would remove the transactions section all together, after the work we’ve done to have all of that output in the INFORMATION_SCHEMA.INNODB_TRX table, I don’t think it’s really required any more..

  5. I also will praise the day they fix the show innodb status info… its totally useless truncated… at the very least they should add “show innodb transaction status” and “show innodb core status” or something, and leave the original output from “show innob status” alone for those who rely on that format not changing…As Mark points out…

    Mark.. agree with you on your last comment… when the INNODB_TRX table becomes widely adopted, there is no need to show the transactions in show innodb status… I am just thinking of a stop-gap solution for those who have not yet moved to the plugin…

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