Is there any wiki/demo/sample for boss_db sharding?

[liuzhen]

I set up two postgresql instances named "db0", "db1", and using following config for db/shards.

seems not working...

{db, [ {adapter, pgsql}, {db_host, "db0"}, {db_port, 5432}, {db_username, "db_username"}, {db_password, "db_password"}, {db_database, "db_database"}, {shards, [ [ {db_shard_models, [user_account, user_message]}, {db_shard_id, db_shard_id0}, % not used in boss_db_controller {db_host, "db0"}, {db_adapter, pgsql}, {db_port, 5432}, {db_username, "db_username"}, {db_password, "db_password"}, {db_database, "db_database"} ], [ {db_shard_models, [user_account, user_message]}, {db_shard_id, db_shard_id1}, {db_adapter, pgsql}, {db_host, "db1"}, {db_port, 5432}, {db_username, "db_username"}, {db_pasword, "db_password"}, {db_database, "db_database"} ]]} }

[liuzhen]

by "seems not working", i meant i tried to insert and query some 'user_accounts' and 'user_messages', all of which were from/into the db0 (config not in the db_shards).

[danikp]

but you do have db0 in your shards

[liuzhen]

@danikp I presume, I have many (more than "user_account" & "user_message") models, the outer db config (db0) is for models other than models specified in db_shards;

As for "user_account" & "user_message", records are to be inserted & looked up in all the shards, i.e. db0 & db1, using some kind of hash or the likes.

In my experiments, db1 in the shards is left intact after many "user_message" insertions.

Would you elaborate?

[danikp]

shards not used for load-balancing. That means, it will use first shard found for specific model. So, if you change your config so user_account will be on db0 and user_message on db1, you should see traffic on both hosts. If you set both models on both shards, only one will be used.

[liuzhen]

Ah, "vertical" sharding, right.

Thanks.

[danikp]

you are welcome!

closing