MySQL 5.1 Stability


I have been helping customer today to resolve his lockups in production by downgrading from MySQL 5.1.25 to 5.0 We have other customers (and our own projects as well) which run on MySQL 5.1 successfully but I can’t it is on par with MySQL 5.0 stability yet.

This given customer was running MyISAM on FreeBSD with quite basic queries, so may be there are some issues with FreeBSD and MySQL 5.1 still ?



  1. Antony Curtis says

    Depends upon which version of FreeBSD…
    FreeBSD < 7 has problems handling mutex contentions. MySQL 5.1 does hit mutexes harder than 5.0.
    AFAIK, these issues has been addressed on FreeBSD 7 but I haven’t examined or tried it yet.

  2. says

    This was FreeBSD 6.3 I think

    I could blame it on FreeBSD but I seen similar situation – queries locking in various states like “end” “freeing items” “Locked” etc on other systems.

  3. says


    Indeed it would be great to get some platform independent diagnostic tool to see where things are stuck.

  4. says


    Indeed 5.1.25 in particular adds this “famous” optimizer regression.

    I would be very careful with optimizer changes in RC stage – unlike normal “bugs” optimizer changes often make things better in some cases but worse in others and it is hard to predict the impact without wide user testing.

  5. Sander says

    I had severe problems with MySQL 5.1 and FreeBSD back in February / March. This was on FreeBSD7 (Release), using InnoDB tables and a few MyISAM tables. And by severe I mean crashes and lockups every few minutes (!).

    After the downgrade to 5.0, everything was running smooth again.

  6. Florent Steiner says

    I have the very same problem on CentOS 5.6 x84_64 on a server with MyISAM tables.

    So I guess it’s not because of FreeBSD.

    Switching back to 5.0 tonight …

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