[SNMP4J] DefaultUDPTransportMapping - java.lang.OutOfMemoryError

[Frank Fock]

Hi Yasen,

By creating a TransportMapping you use 1MB of Memory
by default (with standard Java stack size), because each
TransportMapping uses its own Thread.

Please keep in mind, a TransportMapping is a transport
mapping and *not* a connection! Thus, to access millions of
UDP target addresses, you need only a single (UDP) transport
mapping.

Best regards,
Frank


Yasen Simeonov(NeterraNMT) schrieb:
> Hi Frank,
>
> I have a List that contain objects<PortCrc> with info about devices and 
> ifDesc,
> they are about 100.I am trying to get errors from the ports on every device.
> Unfortunately i have next runtime error:
>
> Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
>     at 
> org.snmp4j.transport.DefaultUdpTransportMapping$ListenThread.<init>(DefaultUdpTransportMapping.java:286)
>     at 
> org.snmp4j.transport.DefaultUdpTransportMapping.listen(DefaultUdpTransportMapping.java:165)
>     at org.snmp4j.Snmp.listen(Snmp.java:390)
>     at 
> yasen.snmp.tools.SnmpV2cGetNext.getValueFromOID(SnmpV2cGetNext.java:60)
>     at Test.main(Test.java:94)
>
>
>
>
>
>
> Next is my code that use the  SNMP class.
>
>     for (int i = 0; i < portCrcList.size(); i++) {
>             PortCrc portCrc = (PortCrc) portCrcList.get(i);
>             Device dev = portCrc.getDevice();
>             SnmpV2cGetNext obj = new SnmpV2cGetNext(dev.getIp(), dev
>                     .getSnmp_ro());
>             String c = null;
>             try {
>                 c = obj.getValueFromOID("1.3.6.1.2.1.2.2.1.14."
>                         + portCrc.getIfdesc());
>             } catch (IOException e) {
>                 e.printStackTrace();
>             }
>             long crc = Long.parseLong(c.trim());
>
>             System.out.println("ID: " + portCrc.getDev_id() + ", DevName: "
>                     + portCrc.getDevname() + ", ifDesc: " + 
> portCrc.getIfdesc()
>                     + ", Port: " + portCrc.getPort() + ", CRC: " + crc);
>         }
>     }
>
>
> And the  SnmpV2cGetNext.java is:
>
>
> public class SnmpV2cGetNext {
>
>     TransportMapping transport;
>     Address targetAddress;
>     CommunityTarget target;
>    
>     public SnmpV2cGetNext(String ip, String community){
>         try {
>             targetAddress = GenericAddress.parse("udp:" + ip + "/161");
>             transport = new DefaultUdpTransportMapping();
>             target = new CommunityTarget();
>             target.setCommunity(new OctetString(community));
>             target.setAddress(targetAddress);
>             target.setRetries(3);
>             target.setTimeout(2000);
>             target.setVersion(SnmpConstants.version2c);
>         } catch (IOException ex) {
>             
> java.util.logging.Logger.getLogger(SnmpV2cGetNext.class.getName()).log(java.util.logging.Level.SEVERE, 
> null, ex);
>         }
>  
>     }
>    
>     public  String getValueFromOID( String oid) throws IOException{
>              PDU pdu = new PDU();
>             pdu.setType(PDU.GETNEXT);
>             pdu.add(new VariableBinding(new OID(oid)));
>             pdu.setNonRepeaters(0);
>             Snmp snmp = new Snmp(transport);
>             snmp.listen();
>             ResponseEvent responseEvent = snmp.send(pdu, target);
>             PDU responsePDU = responseEvent.getResponse();
>             VariableBinding var=new VariableBinding();
>             var=(VariableBinding) 
> responsePDU.getVariableBindings().elements().nextElement();
>             return var.getVariable().toString();
>     }
>
> }
>
> If you have idea how can i avoid this Java heap overflow, please help me.
>
> Best regards,
> Yasen
>
>
>