Starting in SGOS 18.104.22.168 and later, the SGOS has an overload bypass feature which, when enabled, allows new connections to the ProxySG to be bypassed. Once the extreme traffic load subsides or is eliminated, new connections will then be intercepted. However, any existing connections that are bypassed will continue to be bypassed until those connections are closed. By default the ProxySG is configured to drop new connections when resources are scarce.
IMPORTANT NOTE: When the ProxySG is in overload bypass mode (as described below) and new connections are being bypassed, all policy, including bandwidth management, content filtering, ICAP (virus) scanning, and so forth will not be applied to these connections. Please closely monitor any proxy that is susceptible to overloading. Blue Coat recommends that any ProxySG that is susceptible to overload should have the configuration reviewed to make sure poorly implemented policy is not causing the issue. Please see the the Policy Best Practices Technical Brief found at https://bto.bluecoat.com/doc/5181 for more information. If the proxy is continually running in overload mode and the device is properly configured, the device may simply be underpowered for the amount of work it is configured to do. Please contact your reseller or Blue Coat Sales at http://www.bluecoat.com/salesrep/search to see if the ProxySG you have is adequately sized.
Here are the steps necessary in order to enable "resource-overflow-action bypass" for your ProxySG:
Enter configuration commands, one per line. End with CTRL-Z.
ProxySG#(config general)resource-overflow-action bypass