Thread pooling
To this point in the book, whenever we have needed a thread, we've simply called thread::spawn. This is not necessarily a safe thing to do. Let's inspect two projects that suffer from a common defect—potential over-consumption of OS threads. The first will be obviously deficient, the second less so.
Slowloris – attacking thread-per-connection servers
The thread-per-connection architecture is a networking architecture that allocates one OS thread per inbound connection. This works well for servers that will receive a total number of connections relatively similar to the number of CPUs available to the server. Depending on the operating system, this architecture tends to reduce time-to-response latency of network transactions, as a nice bonus. The major defect with thread-per-connection systems has to do with slowloris attacks. In this style of attack, a malicious user opens a connection to the server–a relatively cheap operation, requiring only a single file-handler and simply...
