Re: Checksums by default?

From: Jim Nasby <Jim(dot)Nasby(at)BlueTreble(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Stephen Frost <sfrost(at)snowman(dot)net>
Cc: Peter Geoghegan <pg(at)heroku(dot)com>, Petr Jelinek <petr(dot)jelinek(at)2ndquadrant(dot)com>, Magnus Hagander <magnus(at)hagander(dot)net>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Checksums by default?
Date: 2017-01-24 01:31:02
Message-ID: dafc4400-2d53-2ab2-2009-8e287160d81b@BlueTreble.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On 1/23/17 7:15 PM, Tom Lane wrote:
>> Uhm, Peter G just said that Heroku enables this on all their databases
>> and have yet to see a false-positive report or an issue with having it
>> enabled.
>> That, plus the reports and evidence we've seen in the past couple days,
>> look like a pretty ringing endorsement for having them.
> You must have read a different Peter G than I did. What I read was
>
>>> I don't recall ever seeing a checksum failure on a Heroku Postgres
>>> database,
> which did not sound like an endorsement to me.

Well, it is pretty good evidence that there's no bugs and that false
positives aren't a problem. As I mentioned earlier, my bet is that any
significantly large cloud provider has a ton of things going on behind
the scenes to prevent oddball (as in non-repeating) errors. When you've
got 1M+ servers even small probability bugs can become really big problems.

In any case, how can we go about collecting data that checksums help? We
certainly know people suffer data corruption. We can only guess at how
many of those incidents would be caught by checksums. I don't see how we
can get data on that unless we get a lot more users running checksums.
--
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
Data in Trouble? Get it in Treble! http://BlueTreble.com
855-TREBLE2 (855-873-2532)

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2017-01-24 01:34:24 Re: Online enabling of page level checksums
Previous Message Stephen Frost 2017-01-24 01:29:53 Re: Checksums by default?