Hi, Looking through the source code to check up on a vulnerability in Jackson, I saw that there's a couple of places on master where new *ObjectMapper*s are being created and not reused.
I've found through experience that not reusing ObjectMappers (especially in loops) can have a very detrimental impact on performance. Reuse is recommended: https://github.com/FasterXML/jackson-docs/wiki/Presentation:-Jackson-Performance#basics-things-you-should-do-anyway - "1. Reuse heavy-weight objects: ObjectMapper (data-binding)" ObjectMapper is thread safe once configured. The older uses just create them statically: - org.apache.solr.analytics.AnalyticsRequestParser - org.apache.solr.prometheus.scraper.SolrScraper The new ones I see currently are in - org.apache.solr.security.AuditLoggerPlugin.JSONAuditEventFormatter.formatEvent(AuditEvent) - org.apache.solr.packagemanager.PackageUtils.getMapper() - org.apache.solr.util.SolrJacksonAnnotationInspector.createObjectMapper() I don't know whether these uses are necessarily going to cause performance issues or not, but it's generally best not to new them up inline. Colvin
