Keep Alive Query Max Sleep Time specifies the maximum time (in milliseconds) to wait that after polling keep alive connections for further requests. If your system has extra CPU cycles, keep incrementally increasing this parameter and monitor performance after each incremental increase. When performance saturates (stops improving), then stop increasing the settings.
Set this parameter with asadmin or in the Admin Console HTTP Service page, by choosing Add Property and specifying:
Name: keep-alive-query-max-sleep-time
Value: number of milliseconds