Asymmetric networking using Linux
The idea is simple, two subnets (separate networks) and then route packets from one to the other. The environment, however, is not symmetric. We wanted to contact a node on the other subnet and we could see the packets travelling over the switch to the router back through another switch to the node, but the node itself refused to reply.
Each node has two NICs and each NIC is connected to a separate network. If you try to connect or ping one node from another, Linux is smart enough to go directly over the NIC with the right network. If a NIC should ever fail, the failover is that the packets are then routed up one network to the router then over to the other network.
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threading.Thread vs. multiprocessing.Process
The Feather or the Anvil? 
First a bit of background: I was tasked with created a high level tester for my company’s system. The idea is create 1 or more monkeys to pound away at the company’s product for a very long time. A concurrent parallel programming project with the requirement that it needed to be compatible with 2.6.2 version of Python.
With threading, you get real posix threads (pthread) which works pretty well. They implicitly share state with the parent thread and do not use IPC or messaging. They have low latency and low overall resource footprint.
However there are drawbacks that made further development using threads a real problem. that is the use of signals. Such as threads not handling signals, working with the global interpreter lock (GIL, only one thread allowed to run at a time), and more. Read more
