APAR status
Closed as program error.
Error description
Error Message: none . Stack Trace: . Sample for the concurrent kickoff and exclusive access events in verbose GC logs:<concurrent-kickoff id="3073" timestamp="2013-10-22T00:04:07.656"><kickoff reason="threshold reached" targetBytes="640090591" thresholdFreeBytes="88578344" /></concurrent-kickoff><exclusive-start id="3074" timestamp="2013-10-22T00:04:07.682" intervalms="5898.568"><response-info timems="0.256" idlems="0.093" threads="6" lastid="0000000001DAC300" lastname="Thread-40" /></exclusive-start><cycle-start id="3075" type="global" contextid="0" timestamp="2013-10-22T00:04:07.682" intervalms="392863.183" /><exclusive-end id="3076" timestamp="2013-10-22T00:04:07.682" durationms="0.164" /><exclusive-start id="3077" timestamp="2013-10-22T00:04:07.682" intervalms="0.179"><response-info timems="0.001" idlems="0.001" threads="0" lastid="0000000001709B00" lastname="Thread-18" /></exclusive-start><exclusive-end id="3078" timestamp="2013-10-22T00:04:07.682" durationms="0.016" /><exclusive-start id="3079" timestamp="2013-10-22T00:04:07.683" intervalms="0.032"><response-info timems="0.001" idlems="0.001" threads="0" lastid="00000000016D3500" lastname="Thread-43" /></exclusive-start><exclusive-end id="3080" timestamp="2013-10-22T00:04:07.683" durationms="0.030" />... many additional exclusive events ...<exclusive-start id="3153" timestamp="2013-10-22T00:04:07.806" intervalms="122.347"><response-info timems="0.329" idlems="0.161" threads="39" lastid="0000000001E22200" lastname="Thread-16" /></exclusive-start><concurrent-collection-start id="3154" timestamp="2013-10-22T00:04:07.807" intervalms="392851.710" />
Local fix
Problem summary
In some workloads multiple application threads may simultaneously detect that a concurrent GC should be triggered, and each will attempt to acquire exclusive VM access to perform the concurrent kickoff. The first thread to acquire exclusive access will perform the necessary actions; subsequent threads will each acquire exclusive VM access, determine that no action is required, and release.Each time a thread acquires exclusive VM access, an event is written to the GC verbose log. In the situation described this results in extra log entries. This can be a particular problem when rotating logs are used, since the additional entries reduce the number of informative entries that appear in each log file.
Problem conclusion
This APAR will be fixed in the following Java Releases: 7 SR7 FP1 (7.0.7.1) 7 R1 SR1 FP1 (7.1.1.1) 6 R1 SR8 FP1 (6.1.8.1) . Triggering concurrent GC has been serialized so a single exclusive VM access event will be reported for concurrent kickoff.
Temporary fix
Comments
APAR Information
APAR number
IV59885
Reported component name
J9 COMMON CODE
Reported component ID
620700127
Reported release
260
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2014-04-29
Closed date
2014-05-30
Last modified date
2014-07-15
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
J9 COMMON CODE
Fixed component ID
620700127
Applicable component levels
R260 PSY
UP
R270 PSY
UP
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Document Information
Modified date:
21 February 2022