Hello everyone, We have a use-case which shows about 10 times higher latency for boolean queries after migrating to Lucene 9.2. Each query contains 3 filter clauses and up to a thousand single-term should clauses. They usually return less than 5 documents with a single stored field and used to execute in about 500 ms, but now take more than 5 seconds. Throughput remains roughly the same, about 60 qps.
A compounding factor is that our disk utilization is quite high and usually in the range of 70% to 100%. That seems like an obvious issue, but it did not affect these queries too much before. After the upgrade, we can also see about twice as high kernel CPU utilization. We are currently using NIOFSDirectory. Please let me know if these symptoms mean something to you, it would be great to know if we are doing something wrong and if there is a way to fix the queries without upgrading hardware. Thank you, Alex
