Jan, I made a mistake on that response. Even with ACCELSYS, a program that issues ENQ has to wait until the RSA arrives at the system in order to "see if there are conflicts" and finalize the ENQ. Since the RSA makes its way around the ring system by system in one direction, a second system which wanted to ENQ the resource would see the conflict in the RSA when it arrives. Where ACCELSYS helps is during the second pass of the RSA for any global ENQ (which informs systems of the ENQ having been granted) only X systems need to see the ENQ on the RSA. Therefore there is no integrity exposure during normal operation.
If there was a ring disruption however, and X consecutive systems failed, then it is possible that the system that gets chosen to rebuild the ring may not know about the resource having been granted. That is the exposure and it is documented. Using an ACCELSYS value of half the ring helps to mitigate this recovery scenario. Thanks to Jim Mulder for pointing that out. -Joe Joe Gentile z/OS GRS Lead jwgen...@us.ibm.com ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
