In an excerpt of the AWR report below, I'm seeing several wait events with "Cluster" as the wait class in a RAC environment with 5 nodes and whose version is 11gR2. How will I know which sessions are causing these wait events?
Top 10 Foreground Events by Total Wait Time
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Tota Wait % DB
Event Waits Time Avg(ms) time Wait Class
------------------------------ ------------ ---- ------- ------ ----------
DB CPU 20.1 29.9
gc cr multi block request 690,708 18.3 27 27.3 Cluster
gc cr grant 2-way 1,357,057 8315 6 12.4 Cluster
gc cr grant congested 78,942 5275 67 7.9 Cluster
db file sequential read 2,193,186 2698 1 4.0 User I/O
db file scattered read 850,137 2693 3 4.0 User I/O
external table write 707,925 2657 4 4.0 User I/O
gc current block congested 25,452 1690 66 2.5 Cluster
gc current block 2-way 185,282 1429 8 2.1 Cluster
cursor: pin S wait on X 2,090 1273 609 1.9 Concurrenc