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- From: ken@cs.cornell.edu (Ken Birman)
- Newsgroups: comp.sys.isis
- Subject: Timer overflow causes problems after 4 weeks
- Message-ID: <1992Dec21.004456.16089@cs.cornell.edu>
- Date: 21 Dec 92 00:44:56 GMT
- Organization: Cornell Univ. CS Dept, Ithaca NY 14853
- Lines: 43
-
- We have been shown a problem with Isis under which a timer, stored in
- a 32-bit signed integer with millisecond accuracy, overflows when Isis
- V3.0.6 or Isis V3.0.7 has been running for about 4 weeks.
-
- The symptom is that remote client programs will be dropped by protos
- (much as if Isis had crashed) after about 20 seconds of connect time.
- Basically, protos sheds all its connections and won't make new ones
- using the remote connection code that runs over TCP.
-
- Work-arounds: there are three.
-
- One is to edit the code for the routine isis_disconnect() in cl_isis.c,
- commenting out its disconnect action. In my copy of the obscured cl_isis.c,
- this procedure starts at line 1044:
-
- F7fb29058
- P69bef462()
- {
- B28d3c828 B399ad7b8 *msg;
- address H2ec0cf42;
- if (Z1ac5e3fe() != my_true_pid) {
- /**/
- msg = Ld4f438();
- H2ec0cf42 = X2cbaf53a(CL_CLOSE);
- T78a74ca4(msg, &H2ec0cf42);
- B553dfda4(&H2ec0cf42, msg);
- }
- Ld0b19d0(-1); <-------- COMMENT THIS LINE OUT!
- }
-
- If you are running V2.2 or for some reason can't relink your applications,
- another approach (one that kills performance) is to force Isis to use UDP.
- Do this by setting ISISPORT to a nonsense value so that TCP connections
- will fail. Yet a third option is to reboot your protos servers at least
- once a month.
-
- We'll have a real fix for this in V3.0.8. I apologize to anyone who runs
- into this -- these sorts of timer dependencies are supposed to be handled
- automatically, but obviously we missed one.
- --
- Kenneth P. Birman E-mail: ken@cs.cornell.edu
- 4105 Upson Hall, Dept. of Computer Science TEL: 607 255-9199 (office)
- Cornell University Ithaca, NY 14853 (USA) FAX: 607 255-4428
-