Started by timer38385fa57e79659e9dbe76a85f970686c6c1b44566a45fa57e79659e9dbe76a85f970686c6c1b44566a4refs/remotes/origin/main5fa57e79659e9dbe76a85f970686c6c1b44566a45fa57e79659e9dbe76a85f970686c6c1b44566a4refs/remotes/origin/main5fa57e79659e9dbe76a85f970686c6c1b44566a45fa57e79659e9dbe76a85f970686c6c1b44566a4refs/remotes/origin/mainhttps://gitbox.apache.org/repos/asf/lucene.git080417828testReportfalseJava: 64bit/hotspot/jdk-25.0.4 -XX:+UseCompressedOops -XX:+UseG1GC#38381004264844346Lucene-MMAPv2-Windows #38383838falsefalse3838225862SUCCESS1785444900314https://jenkins.thetaphi.de/view/Lucene/job/Lucene-MMAPv2-Windows/3838/Windows VMlucene/core/src/java/org/apache/lucene/util/hnsw/UpdateGraphsUtils.javalucene/CHANGES.txt5fa57e79659e9dbe76a85f970686c6c1b44566a41785425626000https://jenkins.thetaphi.de/user/noreplynoreplynoreply@github.comFix join set degeneration on low-degree nodes (#16435) UpdateGraphsUtils#computeJoinSet asked for a coverage of 2 for every node with a degree below 9, including nodes with a degree of 1. Such a node can be covered at most once (only its neighbours can cover it), so the coverage was unsatisfiable and the node always ended up in the join set itself. On hub-and-spoke shaped graphs, which HNSW produces for 1-dimensional or heavily duplicated vectors, almost all nodes have a degree of 1, so the join set degenerated to the whole graph and merging lost all its savings. Clamp the requested coverage by the node's degree; graphs where all nodes have a degree of 2 or more are unaffected. Fixes #16251 2026-07-30 11:33:46 -04005fa57e79659e9dbe76a85f970686c6c1b44566a4Fix join set degeneration on low-degree nodes (#16435)editlucene/CHANGES.txteditlucene/core/src/java/org/apache/lucene/util/hnsw/UpdateGraphsUtils.javagithttps://jenkins.thetaphi.de/user/noreplynoreply