bob at redivi.com
Sun Aug 21 14:15:24 EDT 2005
On Aug 21, 2005, at 8:00 AM, Charles Sprickman wrote:
> On Sun, 21 Aug 2005, Francisco Reyes wrote:
>> On Sat, 20 Aug 2005, Bob Ippolito wrote:
>>> Uh yeah. I've had more bad experiences this month with MySQL
>>> than anyone should ever have with a RDBMS. These things are
>>> supposed to be robust and reliable, MySQL is neither. Granted,
>>> we're doing ~150 queries/sec and have > 4GB data in there, but
>>> still. Stay away if you can!
>> I have 20 to 60 queries per second and MySQL is using up 50% to
>> 70% of CPU. What optimizations have you done that you could
> I enjoy it when mysql does this while handling a whopping 20-40
> PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU CPU
> 60151 mysql 64 0 86832K 47436K CPU1 0 35.6H 96.73% 96.73%
> It's bogus of course, the thing is just spinning on something and
> once it's stopped/restarted it uses almost no CPU. Annoying as
> hell though. At least these days it can be gracefully shutdown when
> hung like that. It used to require a -9 to stop it.
> I need to check out where Postgres is at with replication, and how
> well vpopmail is supporting Postgres...
Slony-I is probably what you want for replication.
For backup purposes, you can look into the PITR (point-in-time
recovery) features in 8.0. Basically, the WAL (write-ahead log) can
be shipped off to another machine when they're rolled over, and using
these you can reconstruct the database on another machine if anything
goes wrong. However, you can't actually run the database until
something goes wrong, because you can't add PITR logs to a running
You can also do something similar with Slony-I log shipping, except
Slony-I logs can be imported into a live database. The (only)
reasons to consider PITR are that it's already there, and that it's
simple to configure.
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