![]() Depending on the application type, it may or may not require a rolling restart. Either using an environment variable or similar. In this strategy, you have a change ready to go which instructs your application to start connecting to the new database. Note: These are just suggestions and pg_easy_replicate doesn't provide any functionalities for this. Once that happens you can perform any of the following strategies. Switchover strategies with minimal downtimeįor minimal downtime, it'd be best to watch/tail the stats and wait until switchover_completed_at is updated with a timestamp. $ pg_easy_replicate switchover -group-name database-cluster-2 $ pg_easy_replicate switchover -group-name database-cluster-1 $ pg_easy_replicate start_sync -group-name database-cluster-2 -schema-name public -tables "comments, views " $ pg_easy_replicate bootstrap -group-name database-cluster-2 $ pg_easy_replicate start_sync -group-name database-cluster-1 -schema-name public -tables "users, posts, events " $ pg_easy_replicate bootstrap -group-name database-cluster-1 It is up to user to kick of a rolling restart of your application containers or failover DNS (more on these below in strategies) after the switchover is complete, so that your application isn't sending any read/write requests to the old/source database. The switch is made by putting the user on the source database in READ ONLY mode, so that it is not accepting any more writes and waits for the flush lag to be 0. Switchover will wait until all tables in the group are replicating and the delta for lag is <200kb (by calculating the pg_wal_lsn_diff between sent_lsn and write_lsn) and then perform the switch. Once you have had the time to monitor stats and any other key metrics, you can kick off the switchover. When you start the sync via start_sync, it starts the replication between the two databases. Pg_easy_replicate doesn't kick off the switchover on its own. "application_name ": "pger_subscription_database_cluster_1 ", $ pg_easy_replicate stats -group-name database-cluster-1 Groups are just a logical isolation of a single replication. You can create as many groups as you want for a single database. Pg_easy_replicate version # Prints the version Replicating all tables with a single group Pg_easy_replicate switchover -g, -group-name=GROUP_NAME # Puts the source database in read only mode after all the data is flushed and written Pg_easy_replicate stop_sync -g, -group-name=GROUP_NAME # Stop the logical replication from source database to target database provisioned in the group Pg_easy_replicate stats -g, -group-name=GROUP_NAME # Prints the statistics in JSON for the group Pg_easy_replicate start_sync -g, -group-name=GROUP_NAME # Starts the logical replication from source database to target database provisioned in the group Pg_easy_replicate help # Describe available commands or one specific command Pg_easy_replicate config_check # Prints if source and target database have the required config Pg_easy_replicate cleanup -g, -group-name=GROUP_NAME # Cleans up all bootstrapped data for the respective group Pg_easy_replicate bootstrap -g, -group-name=GROUP_NAME # Sets up temporary tables for information required during runtime Adding internal user to pgBouncer userlistĪdd this line to your application's Gemfile:.Switchover strategies with minimal downtime.Replicating single database with custom tables.Bootstrap and Config Check with special user role in AWS or GCP.Replicating all tables with a single group.This method can be useful for performing minimal downtime (up to <1min, depending) major version upgrades between two PostgreSQL databases, load testing with blue/green database setup and other similar use cases. This ensures zero data loss and minimal downtime for the application. After the source (primary database) is fully replicating, pg_easy_replicate puts it into read-only mode and via logical replication flushes all data to the new target database. pg_easy_replicate also supports switchover. Pg_easy_replicate is a CLI orchestrator tool that simplifies the process of setting up logical replication between two PostgreSQL databases. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |