msc=rose;
C: Client;
S: Server;
B: Backend;
->C: Hit [strong];
box C==C: Generate\nrequest;
C=>S: Request;
box S--S: Check cache;
box S--B: cache miss [tag="Alt\#1"]
{
    S->B: Query;
    S<-B: Response;
}
..: cache hit [tag="Alt\#2"]
{
    S->S: Read\ncache [weak];
};
C<=S: Reply;
---: All done;
