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As discussed in this thread https://www.eclipse.org/forums/index.php/t/1072386/ it seems to be necessary to commit the creation of new tables and indices - which result from registration of new packages - in case of using MySQL InnoDB (standard since MySQL 5.5). This is due to a InnoDB limitation described here: http://dev.mysql.com/doc/refman/5.5/en/innodb-create-index-limitations.html If changes to the table definition are not committed, a select on that table results in the following exception: [ERROR] Rollback in DBStore: org.eclipse.net4j.db.DBException: java.sql.SQLException: Table definition has changed, please retry transaction at org.eclipse.emf.cdo.server.internal.db.mapping.horizontal.AbstractHorizontalMappingStrategy.queryResources(AbstractHorizontalMappingStrategy.java:474) at org.eclipse.emf.cdo.server.internal.db.mapping.horizontal.AbstractHorizontalMappingStrategy.queryResources(AbstractHorizontalMappingStrategy.java:126) at org.eclipse.emf.cdo.server.internal.db.mapping.horizontal.HorizontalMappingStrategy.queryResources(HorizontalMappingStrategy.java:184) at org.eclipse.emf.cdo.server.internal.db.DBStoreAccessor.queryResources(DBStoreAccessor.java:331) at org.eclipse.emf.cdo.spi.server.StoreAccessorBase.readResourceID(StoreAccessorBase.java:215) at org.eclipse.emf.cdo.server.internal.db.mapping.horizontal.AbstractHorizontalClassMapping.checkDuplicateResources(AbstractHorizontalClassMapping.java:469) at org.eclipse.emf.cdo.server.internal.db.mapping.horizontal.HorizontalBranchingClassMapping.writeRevision(HorizontalBranchingClassMapping.java:747) at org.eclipse.emf.cdo.server.internal.db.DBStoreAccessor.writeRevision(DBStoreAccessor.java:591) at org.eclipse.emf.cdo.server.internal.db.DBStoreAccessor.writeRevisions(DBStoreAccessor.java:571) at org.eclipse.emf.cdo.spi.server.StoreAccessor.doWrite(StoreAccessor.java:98) at org.eclipse.emf.cdo.server.internal.db.DBStoreAccessor.doWrite(DBStoreAccessor.java:831) at org.eclipse.emf.cdo.spi.server.StoreAccessorBase.write(StoreAccessorBase.java:152) at org.eclipse.emf.cdo.internal.server.TransactionCommitContext.write(TransactionCommitContext.java:651) at org.eclipse.emf.cdo.internal.server.Repository.initRootResource(Repository.java:2060) at org.eclipse.emf.cdo.internal.server.Repository.doActivate(Repository.java:2213) at org.eclipse.net4j.util.lifecycle.Lifecycle.internalActivate(Lifecycle.java:76) at org.eclipse.net4j.util.lifecycle.ShareableLifecycle.internalActivate(ShareableLifecycle.java:43) at org.eclipse.net4j.util.lifecycle.Lifecycle.activate(Lifecycle.java:162) at org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(LifecycleUtil.java:127) at org.eclipse.net4j.util.lifecycle.LifecycleUtil.activate(LifecycleUtil.java:117) at org.eclipse.emf.cdo.server.CDOServerUtil.addRepository(CDOServerUtil.java:292) at org.eclipse.emf.cdo.spi.server.RepositoryConfigurator.configure(RepositoryConfigurator.java:141) at org.eclipse.emf.cdo.spi.server.RepositoryConfigurator.configure(RepositoryConfigurator.java:108) at enco.sox2.workspace.cdo.server.CDOApplication.doStart(CDOApplication.java:62) at org.eclipse.net4j.util.om.OSGiApplication.start(OSGiApplication.java:63) at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196) at org.eclipse.equinox.internal.app.AnyThreadAppLauncher.run(AnyThreadAppLauncher.java:26) at java.lang.Thread.run(Unknown Source)
A solution to this problem is depicted in https://www.eclipse.org/forums/index.php/t/1072386/ Add a new method to the IDBAdapter interface: needsCommitAfterSchemaModification() Add a conditional commit in DBStoreAccessor.writePackageUnits public void writePackageUnits(InternalCDOPackageUnit[] packageUnits, OMMonitor monitor) { super.writePackageUnits(packageUnits, monitor); IDBAdapter dbAdapter = getStore().getDBAdapter(); if (dbAdapter.needsCommitAfterSchemaModification()) { try { getConnection().commit(); } catch (SQLException e) { OM.LOG.error(e); } } }
I've played with this some ore and found an interesting fix. It appears that the problem only comes up during the initial commit that creates the root resource. And it comes up during the checkDuplicateResources() call. But at this time this call isn't needed at all because the root resource is only created once, never moved, and can't be a duplicate. The fix is simply to skip this call during the very first commit and it seems to work well (your testing is appreciated). The fix is committed to master: http://git.eclipse.org/c/cdo/cdo.git/commit/?id=f11f14a3b2711978ad96d835dd69b2384721bb37
For future reference: I've committed a more aggressive fix that involves an extra commit to my branch "committers/estepper/commit-after-ddl".
Closing.
