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SAP Note 746138 - Analyzing lock table overflows

Note Language: English Version: 10 Validity: Valid Since 03.09.2009

Summary

SymptomThe lock table has overflowed (syslog GEG "Lock table overflow").

Other termsenque, enqueue, lock table overflow, ENQ_OVERFLOW, 16, EnquServerException

Reason and PrerequisitesThe maximum number of locks in the lock table is subject to an upper limitthat is set by the profile parameter enque/table_size. The profileparameter enque/table_size determines the size of the lock table in KBs.You can use transaction SM12 -> "Extras" -> "Statistics" to determine boththe maximum number and current number of entries.The lock table may overflow if:

o the lock table configuration is too small

o an application sets lots of locks

o the update hangs and, as a result, numerous locks inherited by theupdate task exist

Up to now, subsequent analysis could not be performed to determine whichlock types and which lock owners mainly contributed to the lock tableoverflow.

SolutionThe kernel patch described here saves information about the cause of a locktable overflow. This information can be read retrospectively.The kernel patch concerns kernel releases 4.6D, 6.40 and higher.

The following information is saved for the last ten lock table overflows:

o the three lock owners with the most locks

o the three lock arguments with the most locks

Use transaction SM12 to obtain the raw information and particular selectiondata:

o Table: "#01_002"

o Argument: "#01_002"

o Client: "#01"

o User name: "#01_002"

In addition, this information is stored in the file ENQHISOVR in DIR_HOMEon the enqueue server.

The overflow information is written as of the following kernel patchlevels:

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SAP Note 746138 - Analyzing lock table overflows

4.6D: 18566.40: 21

For all higher releases, the overflow information is written as of patchlevel 0.

Header Data

Release Status: Released for CustomerReleased on: 08.09.2009 12:06:14Master Language: GermanPriority: Correction with medium priorityCategory: Help for error analysisPrimary Component: BC-CST-EQ Enqueue

The Note is release-independent

Related Notes

Number Short Text

1081259 EP 7.10: Enqueue overflow during Portal Content Deployment

1012446 Mass transactions: Error message MC603, Lock table overflow

896024 ALPHA: Lock table overflow and endless loop

780077 Locking problem in /FRE/MASS_TRPROD, /F

746373 CST patch collection 26 2004

SP Patch Level

Software Component Version Support Package SP PatchLevel

SAP KERNEL 6.40 32-BIT UNICODE SP224 000224

SAP KERNEL 7.00 32-BIT SP150 000150

SAP KERNEL 7.00 32-BIT UNICODE SP150 000150

SAP KERNEL 7.00 64-BIT SP150 000150

SAP KERNEL 7.00 64-BIT UNICODE SP150 000150

SAP KERNEL 6.40 32-BIT SP224 000224

SAP KERNEL 4.6D_EXT 32-BIT SP2381 002381

SAP KERNEL 4.6D_EXT 64-BIT SP2381 002381

SAP KERNEL 4.6D_EX2 32-BIT SP2381 002381

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SAP Note 746138 - Analyzing lock table overflows

Software Component Version Support Package SP PatchLevel

SAP KERNEL 4.6D_EX2 64-BIT SP2381 002381