Re: Memory leak with Jersey 2.33

[Mark Eggers]

On 1/31/2021 9:39 PM, Mark Eggers wrote:

Folks,





Windows 10 Professional (64 bit, latest updates)
OpenJDK 11.0.10
Apache Tomcat 7.0.107
Jersey Rest 2.33

I have a simple application:

ApplicationConfig:

@ApplicationPath("/service")
public class ApplicationConfig extends Application {

     public ApplicationConfig() {
     }

     @Override
     public Set<Class<?>> getClasses(){
         Set<Class<?>> resources = new java.util.HashSet<>();


resources.add(org.mdeggers.cplanapi.resource.CostInfoResource.class);

resources.add(org.mdeggers.cplanapi.resource.InstituteInfoResource.class);




resources.add(org.mdeggers.cplanapi.mapper.NotFoundExceptionMapper.class);

         return resources;
     }
}

One of three resources:

@Path("/v1/inst")
public class InstituteInfoResource {

     public InstituteInfoResource() {
     }

     @GET
     @Path("/info")
     @Produces({MediaType.APPLICATION_JSON})
     public InstituteContainer getNationalList() {
         InstituteInfo instituteinfo = new InstituteInfo();
         return instituteinfo.getNational();
     }

     @GET
     @Path("/info/{ state : [A-Z]{2} }")
     @Produces({MediaType.APPLICATION_JSON})

         InstituteInfo instituteinfo = new InstituteInfo();
         return instituteinfo.getState(state);
     }
}







SELECT wcl.contextName.toString() AS contextName,
    wcl.started AS started,
    wcl.@retainedHeapSize AS retainedSize
FROM org.apache.catalina.loader.WebappClassLoader wcl

contextName   started      retainedSize
/cplanapi     false        586,720
/docs         true          46,664
/host-manager true          47,288
/manager      true          47,392
/examples     true          85,432
               true          46,912

GC roots for cplanapi are:

class com.sun.naming.internal.ResourceManager
'- propertiesCache java.util.WeakHashMap
    '- table java.util.WeakHashMap$Entry[16]
       '- java.util.WeakHashMap$Entry
          '- referent org.apache.catalina.loader.WebappClassLoader



. . . just my two cents
/mde/

This is probably not a Tomcat issue, but any thoughts on how to resolve this would be greatly appreciated. I am running into an apparent ClassLoader leak with the following configuration: resources.add(org.mdeggers.cplanapi.resource.InstituteTypeInfoResource.class);     public InstituteContainer getStateList(@PathParam("state") String state) { The InstituteInfo class is a DAO that makes requests into a MySQL database and returns a container with the information. This all works, but on undeploying the Tomcat Manager complains that there is a leak after unloading the web application. Doing a heap dump and looking at it with the following OQL in Eclipse MAT shows that the application still resides in memory, with started=false. This occurs on both Windows and Linux, and with the above JRE as well as Java 1.8.0_202.

. . . just my two cents
/mde/

Please ignore this. Doing two rounds of GC through the manager removed the application from memory (as confirmed by a heap dump). Now I need to figure out how to force a GC, since we had an OOM Metaspace issue with repeated deployments of the application.

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