On 05/04/2012 22:17, Ofer Israeli wrote: > Y > > On 5 באפר 2012, at 18:58, "Konstantin Kolinko" <knst.koli...@gmail.com> wrote: > >> 2012/4/5 Ofer Israeli <of...@checkpoint.com>: >>> Mark Thomas wrote: >>>> On 04/04/2012 17:02, Ofer Israeli wrote: >>>> >>>> Once you have an OOME all bets are off. The JVM needs to be restarted. >>>> There is no guarantee of reliable operation after an OOME. >>>> >>>> Mark >>> >>> Hi Mark, >>> I agree that there in such a situation the JVM should be restarted, but it >>> isn't restarted by Tomcat. On the other hand, Tomcat does take some >>> precautious actions and kills the accepting thread, but in such a case it >>> should also close the socket that thread is listening on otherwise it is >>> leaving garbage around after the thread's death. >>> Do you see any reason as not to close the listening socket? >>> >> >> 1. Tomcat does not start JVM thus it cannot restart it. >> >> You need some external tool or script or admin to perform monitoring >> and (re)starts. >> >> 2. OOM can happen at a random place. Once it happens, it is likely >> that other places will also start to fail randomly. It is also likely >> that your attempts to recover will fail as well. >> >> Mark already mentioned it: "all bets are off". >> >> Best regards, >> Konstantin Kolinko >> > Hi Konstantin, > > I agree regarding the OOM bringing TC to a state where it must be restored, > but my point remains: if there is code that handles catching this exception > and terminating the thread, why not terminate gracefully by closing the > listening socket before killing the thread?
And your point has been answered. After an OOM the JVM is in an unknown, unsafe state so a restart MUST occur to restore service. Closing a socket gracefully after an OOM is a bit like trying to shut one of the portholes on the Titanic, shortly after hearing a large crashing sound. There's only one place I know of where Tomcat attempts to interact with OOM conditions and this is not one of them, so I don't believe it's safe to say that Tomcat is deliberately handling this exception. NB an OOM is an Error, not an Exception - it is a subclass of VirtualMachineError, which is thrown to indicate that the Java Virtual Machine is broken or has run out of resources necessary for it to continue operating. An Error is a subclass of Throwable that indicates serious problems that a reasonable application should not try to catch. </end-quote> If anything, the locations where Tomcat catches a Throwable should be modified so it does *not* catch Errors, rather than continuing to do so and then attempting a trivial tidy-up. p -- [key:62590808]
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