highlander

README

A tiny mutex over the network

It might be useful when several distributed components have to organise access around one shared resource.

Build

go build -o highlander main.go

Example

./highlander 127.0.0.1:9000 10

The first call to "take_lock" will receive the lock name.

$ curl -s http://127.0.0.1:9000/take_lock
hrcBMnQa

Further attempts within the maximum expiry time (given as the second parameter, here: 10 seconds) will just give "busy".

$ curl -s http://127.0.0.1:9000/take_lock
busy

With the name, the lock can be released earlier.

$ curl -s http://127.0.0.1:9000/release_lock/hrcBMnQa
ok

So a new lock can be taken.

$ curl -s http://127.0.0.1:9000/take_lock
CLQxYaoc

A restart of the server process will also clear the lock, as everything happens simply in the process memory.