Chris Hegarty 3071c6a055 Modularize Elasticsearch (#81066) ... This PR represents the initial phase of Modularizing Elasticsearch (with Java Modules). This initial phase modularizes the core of the Elasticsearch server with Java Modules, which is then used to load and configure extension components atop the server. Only a subset of extension components are modularized at this stage (other components come in a later phase). Components are loaded dynamically at runtime with custom class loaders (same as is currently done). Components with a module-info.class are defined to a module layer. This architecture is somewhat akin to the Modular JDK, where applications run on the classpath. In the analogy, the Elasticsearch server modules are the platform (thus are always resolved and present), while components without a module-info.class are non-modular code running atop the Elasticsearch server modules. The extension components cannot access types from non-exported packages of the server modules, in the same way that classpath applications cannot access types from non-exported packages of modules from the JDK. Broadly, the core Elasticseach java modules simply "wrap" the existing packages and export them. There are opportunites to export less, which is best done in more narrowly focused follow-up PRs. The Elasticsearch distribution startup scripts are updated to put jars on the module path (the class path is empty), so the distribution will run the core of the server as java modules. A number of key components have been retrofitted with module-info.java's too, and the remaining components can follow later. Unit and functional tests run as non-modular (since they commonly require package-private access), while higher-level integration tests, that run the distribution, run as modular. Co-authored-by: Chris Hegarty <christopher.hegarty@elastic.co> Co-authored-by: Ryan Ernst <ryan@iernst.net> Co-authored-by: Rene Groeschke <rene@elastic.co>		2022-05-20 13:11:42 +01:00
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src/main/java	Modularize Elasticsearch (#81066)	2022-05-20 13:11:42 +01:00
build.gradle	Cleaning up some buildscripts (#85394)	2022-03-31 10:48:48 +02:00