There are some share presentations on Latches Understanding GRS ENQ and Latch Usage and Contention
In this session, the speaker discusses GRS resource consumption and the various IBM tools related to monitoring ENQ and GRS latch contention. Contention is a good indication that something is hung, things changed, or that it's probably not a good idea to scheduled two contentious jobs at the time. Tools include GRS display commands, the GRS EQDQ monitor, and RMF related reporting. Understanding how GRS works with regard to system resources demands such as real storage, XCF and XES is also covered. Another is The Basics of GRS - An Overview of GRS ENQ Processing Lizette > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of Lizette Koehler > Sent: Thursday, December 10, 2015 4:13 AM > To: [email protected] > Subject: Re: Diagnosing a Catalog Enqueue Problem - What does Msg IEC347I tell > me? > > So the number 23136534 is a latch number. I would think additional D GRS > commands could help. > > D GRS,ANALYZE,LATCH,DEPENDENCY,DETAIL > Would be helpful in this case. > > Did you have any jobs running that were backing up the catalog(s)? > Who was the owner of the Enqueue (D GRS,C) What latch was in play (D > GRS,ANALYZE,LATCH,DEPENDENCY,DETAIL) > > There are a few other D GRS commands that might be helpful with these conditions > D GRS,ANALYZE,BLOCKER D GRS,ANALYZE,WAITER > D GRS,ANALYSE,LATCH,BLOCKER <-- the commands book may be wrong, > Might > be ANAYLZE. > > > I always start with the OWNER in a D GRS,C command then see how long it is held. > And work down from there. > > > Lizette > > > > > > -----Original Message----- > > From: IBM Mainframe Discussion List [mailto:[email protected]] > > On Behalf Of Peter Hunkeler > > Sent: Thursday, December 10, 2015 2:36 AM > > To: [email protected] > > Subject: Diagnosing a Catalog Enqueue Problem - What does Msg IEC347I tell me? > > > > We've had a delay which seems to be caused by a problem with catalog > processing. > > Automation regularly issues some MODIFY CATALOG and D GRS commands. > > > > Below is an extract from the response to F CATALOG,LIST (IEC347I) > > IEC347I LIST CATALOG TASK(S) > > > CAS****************************************************************F > > LAGS - TASK ADDRESS - JOBNAME / STEPNAME - ELAPSED TIME - ID *-W-E-- > > 0079C130 P0ANYJOB / DB2RUN 00.01.44 01 * WAITING FOR BCS ENQ > Shr > > Sys FROM 23136534 FOR 00.01.44 *... long list of wainting task follows > here.... > > I tried to find out what the last line above, specifically the 8 digit > > number > behind > > "FROM" are telling me? All of the waiters show the identical 8 digit number. > Could > > not find it, neither in "Managing Catalogs", nor in "System Messages > > -> > IEC347I" nor > > did GIYF help. > > Is this useful information at all when trying to find the causer of the delay? > > GRS tells the catalog that probably is causing the delay: S=SYSTEMS SYSIGGV2 > > SYS1.CATALOG.PLEX.P0.UCAT10SYSNAME JOBNAME ASID TCBADDR > > EXC/SHR STATUSSYSA CATALOG 0033 009AC258 SHARE > OWNSYSC > > CATALOG 0033 00989BC8 EXCLUSIVE WAIT.... long list of > waiters follows > > here... > > > > > > -- > > Peter Hunkeler ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
