GCS/GES Messages Received - number of messages received from remote instances over the hardware interconnect. This statistics generally represents overhead caused by functioning of RAC services. This is statistic is a sum of another two statistics:
GCS/GES messages received = gcs msgs received + ges msgs received
gcs msgs received - number of message received by GCS (Global Cache Service). This statistics is derived from v$ges_statistics.VALUE 'gcs msgs received'.
ges msgs received - number of message received by GES (Global Enqueue Service). This statistics is derived from v$ges_statistics.VALUE 'ges msgs received'.