GAE servlet throwing IncompatibleRemoteServiceException after two days of production running code

Question

I did launch a new version of a web site Sunday afternoon. About 50 users have been using the new service since then. During the night from Monday to Tuesday, one servlet threw an "IncompatibleRemoteServiceException" when exchanging a DTO between the client and the server.

It just looks like a previous version of the server (or client) code was used at some point. Has anyone encountered this type of issue before ?

Any help would be very much appreciated !

javax.servlet.ServletContext log: ExternalService: An IncompatibleRemoteServiceException was thrown while processing this call. com.google.gwt.user.client.rpc.IncompatibleRemoteServiceException: Invalid type signature for com.francecorentstudents.web.client.internal.shared.RegistrationDTO at com.google.gwt.user.server.rpc.RPC.decodeRequest(RPC.java:315) at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:206) at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248) at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62) at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166) at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:102) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:35) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43) at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388) at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216) at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182) at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765) at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418) at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:266) at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152) at org.mortbay.jetty.Server.handle(Server.java:326) at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542) at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923) at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76) at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404) at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:146) at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:447) at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:454) at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:461) at com.google.tracing.TraceContext.runInContext(TraceContext.java:703) at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:338) at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:330) at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:458) at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:251) at java.lang.Thread.run(Thread.java:679) Caused by: com.google.gwt.user.client.rpc.SerializationException: Invalid type signature for com.francecorentstudents.web.client.internal.shared.RegistrationDTO at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamReader.validateTypeVersions(ServerSerializationStreamReader.java:931) at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamReader.deserialize(ServerSerializationStreamReader.java:545) at com.google.gwt.user.client.rpc.impl.AbstractSerializationStreamReader.readObject(AbstractSerializationStreamReader.java:119) at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamReader$ValueReader$8.readValue(ServerSerializationStreamReader.java:138) at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamReader.deserializeValue(ServerSerializationStreamReader.java:385) at com.google.gwt.user.server.rpc.RPC.decodeRequest(RPC.java:303) ... 35 more

Answer 1

If you updated and deployed your code at any time after your initial deployment, one of your clients may be using cached client-side code. See this answer.