EbeanPlugin: Add support for read-only data-sources #118

Activity

1. tamanugi commented on Jan 15, 2019

   

   tamanugi

   on Jan 15, 2019

   Last edited by tamanugi

   More actions

   Any progress on this issue?

   I got error

   Error trying to create the default EbeanServer
   java.lang.RuntimeException: DataSource user is null?
   	at org.avaje.datasource.pool.ConnectionPool.<init>(ConnectionPool.java:207)
   	at org.avaje.datasource.core.Factory.createPool(Factory.java:15)
   	at io.ebeaninternal.server.core.DefaultContainer.getDataSourceFromConfig(DefaultContainer.java:334)
   	at io.ebeaninternal.server.core.DefaultContainer.setDataSource(DefaultContainer.java:278)
   	at io.ebeaninternal.server.core.DefaultContainer.createServer(DefaultContainer.java:117)
   	at io.ebeaninternal.server.core.DefaultContainer.createServer(DefaultContainer.java:88)
   	at io.ebeaninternal.server.core.DefaultContainer.createServer(DefaultContainer.java:45)
   	at io.ebean.EbeanServerFactory.create(EbeanServerFactory.java:58)
   	at io.ebean.Ebean$ServerManager.getWithCreate(Ebean.java:202)
   	at io.ebean.Ebean$ServerManager.<init>(Ebean.java:160)
   	at io.ebean.Ebean$ServerManager.<init>(Ebean.java:133)
   	at io.ebean.Ebean.<clinit>(Ebean.java:127)
   

   package models;
   
   import io.ebean.config.ServerConfig;
   import io.ebean.event.ServerConfigStartup;
   import org.avaje.datasource.DataSourceConfig;
   
   public class MyServerConfigStartup implements ServerConfigStartup {
   
       @Override
       public void onStart(ServerConfig serverConfig) {
               serverConfig.setAutoReadOnlyDataSource(true);
           }
       }
   }

   Is there a workaround or correct setting?

   ref: ebean-orm/ebean#1232

   ---

   Java: 1.8.0_152
   Play: 2.6.13
   Play-Ebean: 4.1.3
2. dwijnand

   added

   status:backlog

   on Feb 14, 2019
3. mkurz

   closed this as completedin #901on Oct 8, 2026
4. mkurz commented on Oct 8, 2026

   

   mkurz

   on Oct 8, 2026

   Member

   More actions

   This got closed by #901. Since this issue covers a few different scenarios, here's a summary of where things stand now:

   1. A read replica of the main database

   Since #892 you configure the replica as an additional Play database, and set it as the read-only data source of the Ebean server:

   db.default.url = "jdbc:postgresql://primary-host/app"
   db.replica.url = "jdbc:postgresql://replica-host/app"
   db.replica.hikaricp.readOnly = true
   
   ebean.default = ["models.*"]
   play.ebean.db.default.readOnlyDatasource = "replica"

   Ebean then runs queries outside of transactions, as well as explicitly read-only transactions, against the replica, using Play's connection pool for it. As the replica is not an Ebean server of its own, no evolutions script gets generated for it.

   This also replaces setAutoReadOnlyDataSource(true) from the comment above, which failed with DataSource user is null?: with that, Ebean creates a connection pool of its own for the read-only queries, and copies the user and password from its own main data source configuration. That one is empty though, because Play provides the main connection pool. (#566 ran into the same problem.)

   2. A separate read-only database, used as an Ebean server of its own (the original request)

   • To keep Play from applying evolutions to it, use Play's per-database setting play.evolutions.db.<name>.enabled = false (which did not exist yet when this issue was opened).
   • To keep Play Ebean from generating its evolutions script, use the new play.ebean.db.<name>.generateEvolutionsScripts = false (Allow turning evolutions script generation on or off per Ebean server #901).

   3. Other combinations

   play.ebean.db.<name>.generateEvolutionsScripts overrides the global play.ebean.generateEvolutionsScripts in both directions, and is independent of Play's evolutions settings on purpose, e.g. for:

   • a database whose evolutions come from the classpath (e.g. from a dependency): turn off the generation, because a generated conf/evolutions/<name>/1.sql takes precedence over those
   • a database to which Play shouldn't apply evolutions, but whose generated script is still wanted, e.g. to hand it to a DBA: keep the generation on, and turn off Play's evolutions for it
   • writing the evolutions yourself: remove the -- Created by Ebean DDL header from the generated script, after that Play Ebean doesn't touch it anymore

   The docs now describe all of this, see "Using a read replica" and "Generating evolution scripts".

   These changes are in main, 8.x and 7.x (#892/#893/#894 and #901/#902/#903), and will be part of the next releases. That's why I think this issue is resolved. If something is still missing for your use case, feel free to re-open it or open a new issue.