A DESCRIPTION OF THE PROBLEM :
TLS session resumption using the included Sun JSSE provider is not working in at least the following versions:

10.0.1
8u172
8u162

It is working in at least:

9.0.1
8u152

REGRESSION : Last worked in version 8u161

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Enable session caching by modifying the SSLContext via:

SSLSessionContext clientContext = ctx.getClientSessionContext();
clientContext.setSessionCacheSize(1000);
SSLSessionContext serverContext = ctx.getServerSessionContext();
serverContext.setSessionCacheSize(5000);

Use an SSLSocket to access openssl s_server -www ... test server as a client
(or have a server with SSLServerSocket and access via openssl s_client -connect ... -reconnect)

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Expect openssl to report that the session is reused, e.g.:

Reused, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES256-SHA384

Alternatively, enable -Djavax.net.debug=ssl and expect to see messages like:

%% Client cached [Session-2, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384]
%% Try resuming [Session-2, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384] from port 54230
update handshake state: client_hello[1]

9.0.1 and 8u152 shows this behavior


ACTUAL -
However, 10.0.1, 8u172, 8u162 show:

%% Client cached [Session-2, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384]
update handshake state: client_hello[1]

and correspondingly openssl shows "New" instead of "Reused".

Note that switching to Google Conscrypt JSSE provider correctly shows session reuse.

FREQUENCY : always