What the option does is close the connection between the proxy and the backend so that HAProxy will analyse further requests instead of just forwarding to the already established connection.
To be fair, I don't know what nginx does - whether connections are kept open or shut down - so I'm not sure that it'd be a fair comparison.
Also interesting are the HAProxy built in SSL times. I'm surprised they're so slow. Perhaps the cipher is also the culprit. The cipher can also be specified in HAProxy.
What the option does is close the connection between the proxy and the backend so that HAProxy will analyse further requests instead of just forwarding to the already established connection.
To be fair, I don't know what nginx does - whether connections are kept open or shut down - so I'm not sure that it'd be a fair comparison.
Also interesting are the HAProxy built in SSL times. I'm surprised they're so slow. Perhaps the cipher is also the culprit. The cipher can also be specified in HAProxy.