compress=yes;
C: Client;
S: Server;
B: Backend;
background.color="blue+90";
->C: Hit;
C=>S: Request;
S>>B: Query;
S<<B: Response;
C<=S: Reply;
background.color=none;
...:\iSome time elapses;
background.color="green+90";
->C: Hit [compress=no];
C=>S: Request;
S>>B: Query;
S<<B: Error [color=red];
C<=S: Error [color=red];

