Curious if this was a single processor CF? We have never had an outage due to a CF even though we have had one fail and structures rebuild into another. I have seen performance "opportunities" that were solved by operating our production data sharing CF's as 2 processor rather than 1 too improve parallel operations with DB2. We made this change circa z9 hardware and subsequently even though engines have continued to get faster will not operate a production CF with less 1 ICF engine.
Best Regards, Sam Knutson, GEICO System z Team Leader mailto:[email protected] (office) 301.986.3574 (cell) 301.996.1318 "Think big, act bold, start simple, grow fast..." -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Markus Haselbach Sent: Tuesday, November 13, 2012 6:12 AM To: [email protected] Subject: Highly used Coupling Facility blocks Sysplex We had an outage cause by an overloaded Coupling Facility. It’s in a parallel sysplex with eight Images and z/OS 1.13 RSU1206 and DB2 10. All images are on Z196, also the CF, with CFCC 17. What happened is that a DB2 CF structure (a group buffer pool) was flooded by applications doing tablespace scan. A lot of directory reclaims occurred. The CF was not able to handle this high number of GBP requests which resulted in increased CPU activity for this structure. The CPU Utilization of the CF got up to 75%. The application has requested more and more GBP entries which slowed down the whole sysplex. Also applications using other structures in the CF had been nearly blocked. Did some experience similar problems with overloaded CF’s ? Brgds Markus Haselbach ==================== This email/fax message is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution of this email/fax is prohibited. If you are not the intended recipient, please destroy all paper and electronic copies of the original message. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
