snmp4j async send() drops pdu responses in case of huge concurrent requests

we are using snmp4j version 1.11.5. it seems the async send() API returns pdu response as null.
But we are able to see the pdu responses in the wireshark packet capture.

we are triggering around 10k the async requests using the 100 threads

This is the known issue or limitation in SNMP4J? Is the issue fixed in the latest releases of SNMP4J?

UDP does not guarantee delivery, it could be that the Java UDP buffer overflows because the application does not read the packets from the Socket fast enough. When a UDP buffer overflows, the Java Runtime (i.e. the operating system) drop any new packet.

SNMP4J 1.11.5 is quite old and you should anyway upgrade to a new version.

But in any case, you need to analyse if there is actually a buffer overflow happening (what is very likely but not 100% sure). You may, for example increase the buffer size in your operating system.