API-Related Changes¶

H2O-3 does its best to keep backwards compatibility between major versions, but sometimes breaking changes are needed in order to improve code quality and to address issues. This section provides a list of current breaking changes between specific releases.

From 3.22 or Below to 3.24¶

Java API¶

The following classes were moved and/or renamed:

Until 3.22	From 3.24
`hex.StackedEnsembleModel`	`hex.ensemble.StackedEnsembleModel`
`hex.StackedEnsembleModel.MetalearnerAlgorithm`	`hex.ensemble.Metalearner.Algorithm`
`ai.h2o.automl.AutoML.algo`	`ai.h2o.automl.Algo`

Some internal methods of StackedEnsemble and StackedEnsembleModel are no longer public, but this should not impact users.

From 3.26 or Below to 3.28¶

Java API¶

The following classes were moved:

Until 3.26	From 3.28
`ai.h2o.automl.EventLog`	`ai.h2o.automl.events.EventLog`
`ai.h2o.automl.EventLogEntry`	`ai.h2o.automl.events.EventLogEntry`
`ai.h2o.automl.Leaderboard`	`ai.h2o.automl.leaderboard.Leaderboard`

From 3.28 or Below to 3.30¶

Java API¶

hex.grid.HyperSpaceWalker and hex.grid.HyperspaceWalker.HyperSpaceIterator interfaces have been simplified. Users implementing those interfaces directly, for example to create a custom grid search exploration algorithm, may want to look at the default implementations in ` h2o-core/src/main/java/hex/grid/HyperSpaceWalker.java` if they are facing any issue when compiling against the new interfaces.