Understanding GC logs.

Hello Experts.

We are getting outofMemory error while routing a large document to TN.
we have implemented large document handling for TN.

Its giving me error like

08-02-04 18:42:16 GMT [ISU.0000.9999W] An exception occurred invoking a processing service for document 51ss1k002ufqcr9a000
002ot. The processing service was lfa.LFA_UKC_CI61CostReportingOutbound.ChartOfAccounts.source.eOne.process:processChartOfAcc
ountsFileReply, and the original error message was: java.lang.OutOfMemoryError: Java heap space. [TRNSERV.000014.000027]
2008-02-04 18:42:16 GMT [ISU.0000.9999W] java.lang.OutOfMemoryError: Java heap space

What does this indicate ??

Min and Max heap is 2048MB on HP Unix jvm .
I enabled GC verbose , but I am not able to interrupt the logs.

1630.161: [GC [PSYoungGen: 627925K->2446K(661696K)] 1055352K->431209K(2059840K), 0.0283509 secs]
2239.419: [GC [PSYoungGen: 629582K->5344K(622848K)] 1058345K->434168K(2020992K), 0.0547284 secs]
12.282: [GC [PSYoungGen: 315077K->15418K(611648K)] 315077K->15418K(2009792K), 0.0995875 secs]

12.382: [Full GC [PSYoungGen: 15418K->0K(611648K)] [PSOldGen: 0K->15280K(1398144K)] 15418K->15280K(2009792K) [PSPermGen: 1897
8K->18978K(262144K)], 0.2541048 secs]

GC time is exceeding GCTimeLimit of 98%

My understanding from the above log in blue is

[PSYoungGen: 15418K->0K(611648K)] - Total size of young generation is 611MB. Before GC it was 0KB and after GC it was 15418KB.So it GC routine freed 15418KB of memory

[PSOldGen: 0K->15280K(1398144K)] - Total size of old generation is 1.39GB. Before GC it was 0KB and after GC it is 15280KB. So GC routing freed 15280KB of memory.

Please correct my understanding if I am wrong. Also what does “GC time is exceeding GCTimeLimit of 98%” indicates ??

Thanks a Lot.
Any comments would be highly appreciated.