In-memory Fuseki keeps growing memory indefinitely even if idle

[Marco Fiocco]

Hello,

I'm running a in-memory Fuseki 3.16 server and I see that the allocated memory 
keeps growing linearly indefinitely even if idle.
Initially I reserved 1GB of memory and I've noticed that the process gets OOM 
killed every 2 hours. Now I've allocated 2GB because I've read somewhere that 
2GB is the minimum for Java heaps. Is that true?
I'm waiting to see if it will get again.
Is this a bug or there is a better way to config it?

My Fuseki config is:

@prefix fuseki:  <http://jena.apache.org/fuseki#> .
@prefix rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs:    <http://www.w3.org/2000/01/rdf-schema#> .
@prefix tdb:     <http://jena.hpl.hp.com/2008/tdb#> .
@prefix ja:      <http://jena.hpl.hp.com/2005/11/Assembler#> .
@prefix :        <#> .

[] rdf:type fuseki:Server .

<#service> rdf:type fuseki:Service ;
    rdfs:label          "Dataset with SHACL validation" ;
    fuseki:name         "ds" ;                                                  
                                                        # See the endpoint url 
in build.gradle
    fuseki:serviceReadWriteGraphStore "data" ;                                  
                                                # SPARQL Graph store protocol 
(read and write)
    fuseki:endpoint     [ fuseki:operation fuseki:query ;       fuseki:name 
"sparql"  ] ;       # SPARQL query service
    fuseki:endpoint     [ fuseki:operation fuseki:shacl ;       fuseki:name 
"shacl" ] ;         # SHACL query service
    fuseki:dataset      <#dataset> .

## In memory TDB with union graph.
<#dataset> rdf:type   tdb:DatasetTDB ;
  tdb:location "--mem--" ;
  # Query timeout on this dataset (1s, 1000 milliseconds)
  ja:context [ ja:cxtName "arq:queryTimeout" ; ja:cxtValue "1000" ] ;
  # Make the default graph be the union of all named graphs.
  tdb:unionDefaultGraph true .

Thanks
Marco