CODEWITHSUNDEEP
erlangerlang-supervisor
legoscia
legoscia

Reputation: 41648

supervisor:start_child vs rest_for_one

If a supervisor uses the rest_for_one restart strategy, and a child is added to it using supervisor:start_child, is the new child considered to be "before" or "after" the existing children?

Or put in another way, if the existing child is A and the new child is B, would B die if A died, or would A die if B died? I presume the former, but the documentation doesn't explicitly state it.

Upvotes: 2

Views: 247

Answers (1)

Vincenzo Maggio
Vincenzo Maggio

Reputation: 3869

From Erlang Documentation

rest_for_one - if one child process terminates and should be 
 restarted, the 'rest' of the child processes -- i.e. the child processes after 
 the terminated child process in the start order -- are terminated. Then the 
 terminated child process and all child processes after it are restarted.

So if you add a child, it will be restarted if any existing child dies but the new child cannot kill any other existing child, the order here is the start order.

Upvotes: 1

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