[Spock Proxy Devel] Different Shards on the same server

[steve <iam...@gm...>]

Hi all,

Spock Proxy looks very interesting! I have a couple of questions:

My 'primary key' for partitioning is in two columns, not one. What to
do? (Two is useful, by the way -- sometimes data is useful to a group
of shards and you can put that in the first column, sort of a shard
group id and then a shard id for that group and when combined, a
primary key of sorts for a shard).

How do you handle failure of a shard, or is that handled elsewhere?

I'm looking at possibly moving to AWS/EC2, and was looking at scalr
(http://code.google.com/p/scalr/) as a way to manage the spinning up
of and auto-managing instances. It would be awesome if Spock Proxy
were directly supported there.

Looking over our queries I see that we do on occasion have three
tables in a query. Often in the case of any join, one table is one in
which to shard upon, and the other (two) are what you call 'universal'
tables.

By the look of the shard_database_directory, by having port_number in
there, it looks like you support having multiple shards running on the
same server. I am a fan of having a mysql master and mysql slaves on
the same server.

Background: In a basic setup of a single master and a single slave on
there own servers, you might run into issues of slave lag since the
mysql slave only has two threads (one each for io and for sql). If the
master was sharded into four mysql instances, as was the slave, then
the slave server would have eight threads running (4 IO and 4 SQL). A
more ideal setup would be that the master and slave(s) would be mixed.
In this case, two master shards on server A and two on server B and
the same for the slaves. To avoid a certain amount of IO contention, I
put each mysql server instance on a separate dirve/array on a
particular machine. Cheaper than raid cards for the same/better
performance.

-s