Our system used to work on RHEL5.3 And the socket receive buffer size is 64k. And that works fine. We can get message size up to 64k on UDP socket.
But after system upgrade, it is running on RHEL6.3 the buffer size is not enough. We can only get message whose size is less than 35k. Enlarged the receive buffer size to 256k, then all came back to normal. Although issue is fixed, I cannot figure out why.
Do you guys have any hint? Appreciate for your input.