The product can be build in threaded or non-threaded mode. The memory leak can be detected only in threaded mode. Hence I think I hit the same issue reported by Thomas in 2012. "One thing I noticed is that all goes well if I cause the code to run sequentially (e.g. cause requests to come one ater another). Yet it starts eating up memory like crazy if I cause several (HTTPS) requests to come at once. " http://openssl.6102.n7.nabble.com/Memory-issues-with-ssl-handshake-td20851.html#a20854. Don't understand why this issue is not encountered by other users and why it has not been fixed for so many years. Thanks, Wang -- Sent from: http://openssl.6102.n7.nabble.com/OpenSSL-User-f3.html -- openssl-users mailing list To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users