Bryan: thank you for your response. I do see the thread you mention:
Thread Group [derby.daemons]{10}(Daemon) Thread [derby.antiGC]{1}(Daemon)(WAITING) Thread [derby.rawStoreDaemon]{5}(Daemon)(TIMED_WAITING) Thread [derby.NetworkServerStarter]{5}(Daemon)(WAITING) Thread [NetworkServerThread_2]{5}(Daemon)(RUNNABLE) Thread [DRDAConnThread_3]{5}(Daemon)(WAITING) However the behavior is still the same - if any other thread stops (for instance in debugger), NetworkServerControl becomes unresponsive. For instance, if I connect to it from the "outside" with another db app (Aqua Data Studio, for instance), then connection to it breaks or the db app can't access it. But as soon as I let the thread run in that debugger, the connection becomes alive and everything seems to work. Has anyone else seen this kind of behavior? Or perhaps, someone can share a piece of code (best practice) of how to instantiate and run the NetworkServerControl, so that it's not experiencing such hang-ups. Much appreciated, Pavel. Bryan Pendleton <bpendle...@amberpoint.com> 02/05/2010 12:07 PM Please respond to "Derby Discussion" <derby-user@db.apache.org> To Derby Discussion <derby-user@db.apache.org> cc Subject Re: Using NetworkServerControl to access in-memory (only) tables of Embedded Derby > DerbyServer thread seems to still be running, yet the server is > unresponsive. In addition to your own DerbyServer thread, which I don't think actually *needs* to still be running, there should be a separate thread which is started by the Derby network server code itself, which has the job of accepting connections and delivering them to other threads to be processed. In my running network server, for example, when I look at the threads that are active, I see: "NetworkServerThread_2" prio=6 tid=0x03044c80 nid=0x27c runnable [0x033cf000..0x033cfae8] at java.net.PlainSocketImpl.socketAccept(Native Method) at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:384) - locked <0x22a857d8> (a java.net.SocksSocketImpl) at java.net.ServerSocket.implAccept(ServerSocket.java:450) at java.net.ServerSocket.accept(ServerSocket.java:421) at org.apache.derby.impl.drda.ClientThread$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at org.apache.derby.impl.drda.ClientThread.run(Unknown Source) Do you see a thread like that? When your server becomes stuck/wedged/unresponsive, why don't you try this: - collect a thread dump of the entire JVM - look through the threads for any which mention "org.apache.derby" in their stacks - edit out all the other threads from your thread dump Then post a message with a cut-and-paste of just the derby-related threads in your wedged server, and maybe it will be more clear to somebody else what the problem is. thanks, bryan Jefferies archives and monitors outgoing and incoming e-mail. The contents of this email, including any attachments, are confidential to the ordinary user of the email address to which it was addressed. If you are not the addressee of this email you may not copy, forward, disclose or otherwise use it or any part of it in any form whatsoever. This email may be produced at the request of regulators or in connection with civil litigation. Jefferies accepts no liability for any errors or omissions arising as a result of transmission. Use by other than intended recipients is prohibited. In the United Kingdom, Jefferies operates as Jefferies International Limited; registered in England: no. 1978621; registered office: Vintners Place, 68 Upper Thames Street, London EC4V 3BJ. Jefferies International Limited is authorised and regulated by the Financial Services Authority.