Websocket is not working with the sandbox environment

WebSocket is not working with the sandbox environment.
Error:

javax.websocket.DeploymentException: The HTTP request to initiate the WebSocket connection failed
    at org.apache.tomcat.websocket.WsWebSocketContainer.connectToServerRecursive(WsWebSocketContainer.java:485)
    at org.apache.tomcat.websocket.WsWebSocketContainer.connectToServer(WsWebSocketContainer.java:194)
    at org.springframework.web.socket.client.standard.StandardWebSocketClient$1.call(StandardWebSocketClient.java:150)
    at org.springframework.web.socket.client.standard.StandardWebSocketClient$1.call(StandardWebSocketClient.java:147)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.util.concurrent.ExecutionException: javax.net.ssl.SSLException: Received fatal alert: handshake_failure
    at org.apache.tomcat.websocket.AsyncChannelWrapperSecure$WrapperFuture.get(AsyncChannelWrapperSecure.java:512)
    at org.apache.tomcat.websocket.WsWebSocketContainer.connectToServerRecursive(WsWebSocketContainer.java:343)
    ... 5 common frames omitted
Caused by: javax.net.ssl.SSLException: Received fatal alert: handshake_failure
    at sun.security.ssl.Alerts.getSSLException(Alerts.java:208)
    at sun.security.ssl.SSLEngineImpl.fatal(SSLEngineImpl.java:1666)
    at sun.security.ssl.SSLEngineImpl.fatal(SSLEngineImpl.java:1634)
    at sun.security.ssl.SSLEngineImpl.recvAlert(SSLEngineImpl.java:1800)
    at sun.security.ssl.SSLEngineImpl.readRecord(SSLEngineImpl.java:1083)
    at sun.security.ssl.SSLEngineImpl.readNetRecord(SSLEngineImpl.java:907)
    at sun.security.ssl.SSLEngineImpl.unwrap(SSLEngineImpl.java:781)
    at javax.net.ssl.SSLEngine.unwrap(SSLEngine.java:624)
    at org.apache.tomcat.websocket.AsyncChannelWrapperSecure$WebSocketSslHandshakeThread.run(AsyncChannelWrapperSecure.java:392)

Ref: https://stackoverflow.com/questions/49648694/java-websocket-client-not-working-with-gdax-sandbox-environment

[robevansuk]

Sandbox is no longer a fully functioning environment - treat it as dead. Coinbase shut it down last year but it appears portions of it were left running which is confusing for a lot of developers.

SSL debug log:

[Raw read]: length = 5
0000: 15 03 01 00 02                                     .....
[Raw read]: length = 2
0000: 02 28                                              .(
Thread-2, READ: TLSv1 Alert, length = 2
Thread-2, RECV TLSv1.2 ALERT:  fatal, handshake_failure
Thread-2, fatal: engine already closed.  Rethrowing javax.net.ssl.SSLException: Received fatal alert: handshake_failure
Thread-2, fatal: engine already closed.  Rethrowing javax.net.ssl.SSLException: Received fatal alert: handshake_failure
09:44:20.205 [SimpleAsyncTaskExecutor-1] ERROR org.springframework.web.socket.client.WebSocketConnectionManager - Failed to connect

[irufus]

Sandbox works for testing all the REST endpoints. I have yet to confirm if the socket is still down but will open up a new issue if that's the case when we try to add more test coverage in the library.