liangkaiwen opened a new pull request, #4935: URL: https://github.com/apache/solr/pull/4935
https://issues.apache.org/jira/browse/SOLR-18476 <!-- _(If you are a project committer then you may remove some/all of the following template.)_ Before creating a pull request, please file an issue in the ASF Jira system for Solr: * https://issues.apache.org/jira/projects/SOLR For something minor (i.e. that wouldn't be worth putting in release notes), you can skip JIRA. To create a Jira issue, you will need to create an account there first. The title of the PR should reference the Jira issue number in the form: * SOLR-####: <short description of problem or changes> SOLR must be fully capitalized. A short description helps people scanning pull requests for items they can work on. Properly referencing the issue in the title ensures that Jira is correctly updated with code review comments and commits. --> # Description Existing usage of `preload=true` will attempt to load the entire index (filesystem) directory into OS page cache indiscriminately. This can be a problematic take on a good idea in 2 ways: 1) you may not want to run this long synchronous preload over the entire index and 2) you may not have enough physical memory to fit the whole index, so having the ability to prioritize some index files over others would be more practical/useful. # Solution Coded using Claude 5.0 Opus * Added "preloadExtensions" to MMapDirectoryFactory config definition, which allows a comma separate list of file extensions to be provided (does not need to be used in conjunction with preload=true) * MMapDirectoryFactory's create function uses a preload predicate depending on the configuration. Extensions predicate matches files with extension (after last .) matching any of the provided in the configuration * When preload=true is provided and preloadExtensions is provided, preloadExtensions behavior will take precedence (whole index not preloaded) # Tests * Add unit tests for MMapDirectoryFactory * Check OS off-heap memory metrics # Checklist Please review the following and check all that apply: - [X] I have reviewed the guidelines for [How to Contribute](https://github.com/apache/solr/blob/main/CONTRIBUTING.md) and my code conforms to the standards described there to the best of my ability. - [X] I have created a Jira issue and added the issue ID to my pull request title. - [X] I have given Solr maintainers [access](https://help.github.com/en/articles/allowing-changes-to-a-pull-request-branch-created-from-a-fork) to contribute to my PR branch. (optional but recommended, not available for branches on forks living under an organisation) - [X] I have developed this patch against the `main` branch. - [X] I have run `./gradlew check`. - [X] I have added tests for my changes. - [X] I have added documentation for the [Reference Guide](https://github.com/apache/solr/tree/main/solr/solr-ref-guide) - [X] I have added a [changelog entry](https://github.com/apache/solr/blob/main/dev-docs/changelog.adoc) for my change -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
