open-consul/agent/cache
R.B. Boyer 9f41cc4a25
cache: prevent goroutine leak in agent cache (#14908)
There is a bug in the error handling code for the Agent cache subsystem discovered:

1. NotifyCallback calls notifyBlockingQuery which calls getWithIndex in
   a loop (which backs off on-error up to 1 minute)

2. getWithIndex calls fetch if there’s no valid entry in the cache

3. fetch starts a goroutine which calls Fetch on the cache-type, waits
   for a while (again with backoff up to 1 minute for errors) and then
   calls fetch to trigger a refresh

The end result being that every 1 minute notifyBlockingQuery spawns an
ancestry of goroutines that essentially lives forever.

This PR ensures that the goroutine started by `fetch` cancels any prior
goroutine spawned by the same line for the same key.

In isolated testing where a cache type was tweaked to indefinitely
error, this patch prevented goroutine counts from skyrocketing.
2022-10-17 14:38:10 -05:00
..
cache.go cache: prevent goroutine leak in agent cache (#14908) 2022-10-17 14:38:10 -05:00
cache_test.go cache: prevent goroutine leak in agent cache (#14908) 2022-10-17 14:38:10 -05:00
entry.go
mock_Request.go
mock_Type.go
request.go
testing.go
type.go
watch.go
watch_test.go