Greetings all, In the process of following up on this thread in the users mailing list: https://lists.apache.org/thread/96ndn3n999dxpm71xjcwr4c6bjpd4sdy, we ran the solr-benchmark project on various local development builds of Solr. For context, this benchmark (https://github.com/pavel-chumakou/solr-benchmark) repeats a set of 20 queries over an index of selected Wikipedia articles. Running Solr locally, we saw the following results (all from a cold start):
- Solr 9.8.0: Search time, ms: 742 473 390 375 381 307 380 327 297 334 304 386 342 315 286 308 311 285 306 430 - Solr 9.7.0: Search time, ms: 767 479 398 331 314 308 289 296 336 339 324 325 286 288 294 288 307 299 399 295 - Solr 9.6.1: Search time, ms: 328 59 7 8 6 4 8 6 2 2 1 2 1 2 2 2 1 1 2 2 After observing this discrepancy, we used the JFR to profile our local builds of Solr while running the benchmark. This led us to the following discovery: - Build of upstream commit b8410234: Search time, ms: 1026 741 704 674 624 604 841 719 630 614 642 610 629 599 626 592 617 616 626 603 - Build of the previous upstream commit (08a2bdd1): Search time, ms: 385 81 39 13 3 7 6 8 6 5 4 27 75 2 3 4 2 1 1 2 Without drawing any conclusions, our observations indicate that some change related to the above commit is causing major performance degradation. This would align with the various reports of performance degradation following the release of Solr 9.7. All benchmarks above were run on an M3 Macbook Pro with Temurin Java 21.0.5. To execute each benchmark, we ran the following commands: git clone https://github.com/pavel-chumakou/solr-benchmark.git cd solr-benchmark unzip wikitest.zip cd apache/solr git checkout releases/solr/9.x.x ./gradlew clean dev cd solr/packaging/build/dev cp -r ~/solr-benchmark/wikitest/ ./server/solr/wikitest/ bin/solr start cd ~/solr-benchmark java RunSolrQuery.java
