[[breaking-changes-5.0]] == Breaking changes in 5.0 This section discusses the changes that you need to be aware of when migrating your application to Elasticsearch 5.0. [float] === Indices created before 5.0 Elasticsearch 5.0 can read indices created in version 2.0 and above. If any of your indices were created before 2.0 you will need to upgrade to the latest 2.x version of Elasticsearch first, in order to upgrade your indices or to delete the old indices. Elasticsearch will not start in the presence of old indices. To upgrade 2.x indices, first start a node which have access to all the data folders and let it upgrade all the indices before starting up rest of the cluster. [IMPORTANT] .Reindex indices from Elasticseach 1.x or before ========================================= Indices created in Elasticsearch 1.x or before will need to be reindexed with Elasticsearch 2.x in order to be readable by Elasticsearch 5.x. The easiest way to do this is to upgrade to Elasticsearch 2.3 or later and to use the `reindex` API. ========================================= [float] === Also see: * <> * <> * <> * <> * <> * <> * <> * <> * <> * <> * <> * <> include::migrate_5_0/search.asciidoc[] include::migrate_5_0/mapping.asciidoc[] include::migrate_5_0/percolator.asciidoc[] include::migrate_5_0/index-apis.asciidoc[] include::migrate_5_0/settings.asciidoc[] include::migrate_5_0/allocation.asciidoc[] include::migrate_5_0/rest.asciidoc[] include::migrate_5_0/cat.asciidoc[] include::migrate_5_0/java.asciidoc[] include::migrate_5_0/packaging.asciidoc[] include::migrate_5_0/plugins.asciidoc[] include::migrate_5_0/fs.asciidoc[]