The worlds smallest Slony cluster?

We recently updated on of our Slony clusters. I think it at least used to qualify as one of the worlds smallest ones:

  • Two nodes (obvious minimum)
  • one database (that's a given)
  • with one table
  • with one column
  • with one row

Now, we recently doubled the size of this cluster. It now has a whopping two columns in the table. The second column being updated by a trigger, so it's still only one column updated by the end user (well, application). But it's two columns to be replicated!

So what does this prove? Really, not much, but at least: Slony certainly scales "downward" just fine. It feels like a bit overhead to set it up for something like this, but it works just fine. Even in a small database, triggers can be very useful - regardless of what the documentation of a certain other database used to say before... And even in a trivial case like this, statement based replication simply does not work reliably*. You need something that's data based - something that the same other database is actually recognizing now and will be including the next version...


Conferences

I speak at and organize conferences around Open Source in general and PostgreSQL in particular.

Upcoming

PGDay.UK
Jul 4, 2017
London, UK
PGDay.RU
Jul 5-7, 2017
St Petersburg, Russia
PGConf.EU 2017
Oct 24-27, 2017
Warsaw, Poland

Past

PGCon 2017
May 23-26, 2017
Ottawa, Canada
FOSS-North
Apr 26, 2017
Gothenburg, Sweden
pgDay.paris 2017
Mar 23, 2017
Paris, France
Nordic PGDay 2017
Mar 21, 2017
Stockholm, Sweden
Confoo Montreal 2017
Mar 8-10, 2017
Montreal, Canada
More past conferences