make misc_node process exec more robust based on stress testing.
make misc_node process exec more robust based on stress testing.

tscholl2/smc,sagemathinc/smc,sagemathinc/smc,tscholl2/smc,sagemathinc/smc,DrXyzzy/smc,tscholl2/smc,DrXyzzy/smc,DrXyzzy/smc,sagemathinc/smc,DrXyzzy/smc,tscholl2/smc,tscholl2/smc