![]() We assume the PostgreSQL client is installed in the host too for this article. The advantage of Docker as demonstration tool is that these procedures should beĮasy to replicate as is and it also takes care of creating and running the databases as well. We use Docker to run PostgreSQL in our servers (besides the apps), so this article also uses it toĭemonstrate how the process works, but it should be easy to apply the instructions to other kind The final switch can happen in as quickly as a few seconds, which means minimal downtime. This would be the case if you're using DB.register_row_type using the Sequel Ruby gem, for Have registered those row types it won't work as expected until you reboot the application. Some custom types such as row types, as they will most likely have different OIDs and if you The port in the new cluster to match the old one, stop the old cluster and restart the new one.įinally it would be a good idea to restart the applications as well, specially if you're using Once the replication is finished, you may change Subscription, which starts the replication. Pg_hba.conf are changed to enable logical replication and both databases are restarted.įinally, some pglogical statements are issued to create the provider, subscriber and The pglogical extension is created in both databases, nf and (the 9.6 database being upgraded) the IP and port for the subscriber (the new PG 10 database)Īnd vice-versa. TheĬlusters should be reachable to it other through TCP/IP. Should be stopped and restarted using the pglogical-enabled installed PostgreSQL. The idea is to install a PostgreSQL package with support for the pglogical extension, thenĬreate the new PG 10 cluster and restore the schema only in the new cluster. If that's your case:Īlter table schema_migrations add primary key (version) Schema_migrations table didn't have a primary key in the earlier days. Using the ActiveRecord Ruby gem to manage the database migrations in older databases as the You should pay special attention to the primary key requirement though, specially if you're Superuser access must alsoīe provided for both databases for the replication agents. It doesn't need to be a single column, but a primary key must exist. Well, PG 10 added some support to logical replication, but since we want to replicateįrom 9.6, we'd need to resort to some external extension.Ī required condition from pglogical is that all tables being replicated must have a primary key. Versions, which is not possible with the binary replication mechanism provided by PostgreSQL Pglogical implements logical replication, which allows replicating databases among different ![]() Give it a try, which allowed me to switch from 9.6 to 10 in just a few seconds. More about pglogical, I decided to finally That means the application wouldn't be available for an hour or so, maybe more. The new cluster and switch off the maintenance mode. ![]() The way I was used to: put the application in maintenance mode, get a new dump and restore it to It would require a lot of coordination effort to get a maintenance window to perform the migration For CSS resets and the like, change their extensions to scss and drop them into the sass directory.Once PostgreSQL 10 was released I wanted to upgrade our 9.6 cluster to the newest version.
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