How to determine the report associated a virt* temp file

Issue Description

Temp files that are prefixed with 'virt' are created during JasperReport API's file virtualization feature to impact memory consumption of reports with very large number of pages. These files can sometimes be found in the /temp directory of your application server. The files are mostly binary but it is possible to determine the original report related to these temp files

Resolution

Associating a virt file to a report is possible via debug logging by following the thread name across messages, but this is not easy.

You can add com.jaspersoft.jasperserver.api.engine.jasperreports.service.impl.EngineServiceImpl as DEBUG to the loggers. This gives you report path:

 2020-06-22 07:10:30,938 DEBUG EngineServiceImpl,http-nio-8090-exec-12:661 - Running report /public/Ad_Hoc_View_Report on java.util.concurrent.ThreadPoolExecutor@4a1b42e0[Running, pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 8]

It also gives you the thread:

2020-06-22 07:10:30,954 DEBUG EngineServiceImpl,pool-5-thread-6:1050 - Initiating report execution for /public/Ad_Hoc_View_Report

Also add net.sf.jasperreports.engine.base.ElementsBlock as DEBUG . This helps you see the ids logged by ElementsBlock for the pool-5-thread-6, like:

2020-06-22 07:10:31,133 DEBUG ElementsBlock,pool-5-thread-6:82 - generated uid 937277692_947004244_46120_-2016077548 for net.sf.jasperreports.engine.base.ElementsBlock@38722354

The 'generated uid' in the log line above is part of the virt* filename.

Ref. Case 01874245