What are the implications of changing socket buffer sizes?

We will discuss What are the implications of changing the values of the following parameters 

/proc/sys/net/core/rmem_default = 524288
/proc/sys/net/core/rmem_max = 524288
/proc/sys/net/core/wmem_default = 52428
/proc/sys/net/core/wmem_max = 524288

• Increasing the rmem/wmem will increase the buffer size allocated to every socket opened on the system. These values need to be tuned as per your environment and requirements. A higher value may increase throughput to some extent, but will affect latency. So, you need to determine which is important for you, and a value can only be arrived by repetitive testing.

• When buffering is enabled, a packet received is not immediately processed by the receiving application. With a large buffer this delay gets increased, as the packet has to wait for the buffer backlog to be emptied before it gets it's turn for processing.

• Buffering is good to increase throughput, because by keeping the buffer full, the receiving application will always have data to process. But, this affects latency, as packets have to wait longer in the buffer before being processed. For more information on this also visit: Bufferbloat: http://en.wikipedia.org/wiki/Bufferbloat