Hi, I’m seeing reproducible failures with SolrJ 10.0.0’s HttpJdkSolrClient against Solr 10.0.0 using Java 25 and HTTP cleartext (h2c).
Using a single client, the first client.add(...) succeeds. After waiting 35 seconds, a second update fails with: java.io.IOException: RST_STREAM received Protocol error The same sequence succeeds when forcing HTTP/1.1 or reducing the idle interval to 3 seconds. I’ve created a small standalone Docker reproducer: https://github.com/micopiira/solrj-h2c-idle-reproducer. Running ./reproduce.sh reproduces the failure and captures client and server diagnostics. My suspicion is that maybeTryHeadRequest() caches the successful initial HEAD by base URI, but that cached result survives the underlying connection expiring. The replacement connection then attempts an h2c upgrade with a chunked POST. Diagnostics show Jetty returning RST_STREAM and GOAWAY with invalid_preface. Is this a known issue, or should I open a Jira ticket with the reproducer and findings? Thanks, Mico
