mirror of https://github.com/status-im/consul.git
b014c0f91b
see: https://github.com/hashicorp/consul/issues/1173 #1173 Reasoning: somewhere during consul development Pause()/Resume() and PauseSync()/ResumeSync() were added to protect larger changes to agent's localState. A few of the places that it tries to protect are: - (a *Agent) AddService(...) # part of the method - (c *Command) handleReload(...) # almost the whole method - (l *localState) antiEntropy(...)# isPaused() prevents syncChanges() The main problem is, that in the middle of handleReload(...)'s critical section it indirectly (loadServices()) calls AddService(...). AddService() in turn calls Pause() to protect itself against syncChanges(). At the end of AddService() a defered call to Resume() is made. With the current implementation, this releases isPaused() "lock" in the middle of handleReload() allowing antiEntropy to kick in while configuration reload is still in progress. Specifically almost all services and probably all check are unloaded when syncChanges() is allowed to run. This in turn can causes massive service/check de-/re-registration, and since checks are by default registered in the critical state, a majority of services on a node can be marked as failing. It's made worse with automation, often calling `consul reload` in close proximity on many nodes in the cluster. This change basically turns Pause()/Resume() into P()/V() of a garden-variety semaphore. Allowing Pause() to be called multiple times, and releasing isPaused() only after all matching/defered Resumes() are called as well. TODO/NOTE: as with many semaphore implementations, it might be reasonable to panic() if l.paused ever becomes negative. |
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| .. | ||
| agent | ||
| configtest.go | ||
| configtest_test.go | ||
| event.go | ||
| event_test.go | ||
| exec.go | ||
| exec_test.go | ||
| force_leave.go | ||
| force_leave_test.go | ||
| info.go | ||
| info_test.go | ||
| join.go | ||
| join_test.go | ||
| keygen.go | ||
| keygen_test.go | ||
| keyring.go | ||
| keyring_test.go | ||
| leave.go | ||
| leave_test.go | ||
| lock.go | ||
| lock_test.go | ||
| maint.go | ||
| maint_test.go | ||
| members.go | ||
| members_test.go | ||
| monitor.go | ||
| reload.go | ||
| reload_test.go | ||
| rpc.go | ||
| rpc_test.go | ||
| util_test.go | ||
| util_unix.go | ||
| util_windows.go | ||
| version.go | ||
| version_test.go | ||
| watch.go | ||
| watch_test.go | ||