Google appengine memcache throwing on get call from a GWT RPC call - google-app-engine

Question

When calling memcache from within GWT, I get the following exception:
2019-02-16 13:17:52.921:WARN:/:qtp1987848069-60: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.lang.String example.client.GreetingService.greetServer(java.lang.String) throws java.lang.IllegalArgumentException' threw an unexpected exception: com.google.apphosting.api.ApiProxy$CallNotFoundException: Can't make API call memcache.Get in a thread that is neither the original request thread nor a thread created by ThreadManager
at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:416)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:605)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:333)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:303)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:373)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:587)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:577)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.handler.RequestLogHandler.handle(RequestLogHandler.java:95)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.Server.handle(Server.java:499)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:257)
at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
at java.lang.Thread.run(Thread.java:748)
Caused by:
com.google.apphosting.api.ApiProxy$CallNotFoundException: Can't make API call memcache.Get in a thread that is neither the original request thread nor a thread created by ThreadManager
at com.google.apphosting.api.ApiProxy$CallNotFoundException.foreignThread(ApiProxy.java:800)
at com.google.apphosting.api.ApiProxy$1.get(ApiProxy.java:175)
at com.google.apphosting.api.ApiProxy$1.get(ApiProxy.java:172)
at com.google.appengine.api.utils.FutureWrapper.get(FutureWrapper.java:89)
at com.google.appengine.api.memcache.MemcacheServiceImpl.quietGet(MemcacheServiceImpl.java:26)
at com.google.appengine.api.memcache.MemcacheServiceImpl.get(MemcacheServiceImpl.java:49)
at example.server.GreetingServiceImpl.greetServer(GreetingServiceImpl.java:38)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:587)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:333)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:303)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:373)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:587)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:577)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.handler.RequestLogHandler.handle(RequestLogHandler.java:95)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.Server.handle(Server.java:499)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:257)
at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
at java.lang.Thread.run(Thread.java:748)
I've looked through other posts with this type of exception and the problem is that the server (jetty) is using a thread pool instead of the original request thread to service the call.
How do I work around this?
Here is the call to memcache:
MemcacheService memCache = MemcacheServiceFactory.getMemcacheService();
memCache.setErrorHandler(ErrorHandlers.getConsistentLogAndContinue(Level.INFO));
memCache.get("test");
After pondering Colin's comment, perhaps the question should be:
When running within the local GWT dev mode, can Jetty be configured to handle the request with the originating thread as opposed to using a pool? (as per appengine within Java 8)
Or from the other direction:
How do I configure the appengine launch configuration within eclipse so that it can run a GWT application?