Lab guidance

Hardness of assignments

Each task indicates how difficult it is:

Easy: A few hours.
Moderate: ~ 6 hours (per week).
Hard: More than 6 hours (per week). If you start late, your solution is unlikely to pass all tests.

These times are rough estimates of our expectations.

The tasks in general require not many lines of code (a few hundred lines), but the code is conceptually complicated and often details matter a lot. Some of the tests are difficult to pass.

Don't start a lab the night before it is due; it much more time efficient to do the labs in several sessions spread over multiple days. Tracking down bugs in distributed system code is difficult, because of concurrency, crashes, and an unreliable network. It requires thought and careful debugging to understand and fix.

Development/Debugging tips

Learn Go. Do Online Go tutorial and consult How to write Go code. See Editors to set up your editor for Go.
Use Go's race detector, with go build -race and go run -race. Fix any races it reports.
Read guide for Raft specific advice.
Advice on locking in labs.
Advice on structuring lab software.
A good way to debug your code is to insert print statements when a peer sends or receives a message, and collect the output in a file with go test -race > out. Then, by studying the trace of messages in the out file, you can identify where your implementation deviates from the desired protocol.
You might want to structure your debug message in a specific format so that you can use grep to search easily for specific lines in out.
You might find DPrintf useful instead of calling log.Printf directly to turn printing on and off as you debug different problems.
To learn more about git, look at the Pro Git book or the git user's manual.

It is well worth the time to follow these tips.