We've been having a problem where our ObjectDB server goes unresponsive every 2 days or so. I've reviewed the server-side logs, and there are no events logged shortly before the crash. Once the server gets in this state, it is unresponsive to bin/server.sh restart; I have had to reboot the entire server on which it's running. The only recorded symptom is a client-side error (which fortunately gets auto-mailed to me):
[ObjectDB 2.5.2] javax.persistence.PersistenceException Mismatch client-server protocol prefix (error 523) at com.objectdb.jpa.JpaQuery.getSingleResult(JpaQuery.java:723) at org.apache.jsp.status_jsp._jspService(status_jsp.java:101) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:722) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334) at javax.servlet.http.HttpServlet.service(HttpServlet.java:722) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at com.fastmodel.fastplan.db.EntityManagerFactory.doFilter(EntityManagerFactory.java:202) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) at org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:680) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) at java.lang.Thread.run(Thread.java:679) Caused by: com.objectdb.o.UserException: Mismatch client-server protocol prefix at com.objectdb.o.MSG.d(MSG.java:61) at com.objectdb.o.SCO.b(SCO.java:210) at com.objectdb.o.NTS.z(NTS.java:287) at com.objectdb.o.CLS.S(CLS.java:340) at com.objectdb.o.CLS.Q(CLS.java:282) at com.objectdb.o.CST.U6(CST.java:501) at com.objectdb.o.QRR.g(QRR.java:244) at com.objectdb.o.QRR.f(QRR.java:153) at com.objectdb.jpa.JpaQuery.getSingleResult(JpaQuery.java:716) ... 27 more
I realize this isn't a lot to go on; I can provide a snapshot of our database via private channel if you would like.