It was my understanding that tasks enqueueing on a resource are getting control in FIFO order, if contention existed. Today, we had a situation where this was not true.
Environment is as follows: - 4 system parallel sysplex, z/OS V1.13, GRS STAR mode. - a dozen or so jobs running the same program are active across all 4 systems at a time. More job being submitted as jobs end (more or less). - the programs are serializing using EXCLUSIVE ENQ on a resource, scope systems As expected, one job is running, all others are waiting to get the resource assigned. But suddenly, we the recognized that jobs on two systems never got running. They have been waiting for the resource for hours, while newer jobs got control one after the other. So resource assignment is clearly not FIFO. We then saw (in EJES) that once a job ended, all waiting jobs are active for a very short time, then one job continues to run while all other are waiting again. I have RTFM, and still think ENQ is FIFO. I have not found anything related to GRS STAR mode that contradicts. I have not followed GRS new lately. What am I missing? -- Peter Hunkeler ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
