Reviewed 3 of 3 files at r1, 1 of 1 files at r2, all commit messages.
Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @knz and @rauchenstein)

pkg/rpc/context.go, line 1198 at r2 (raw file):

					if err != nil && !grpcutil.IsClosedConnection(err) &&
						!grpcutil.IsConnectionRejected(err) {
						log.Health.Errorf(masterCtx, "removing connection to %s due to error: %v", target, err)

Wait, this makes a difference? What am I missing? https://go.dev/play/p/wbpx20tXsAu

pkg/rpc/heartbeat_test.go, line 161 at r1 (raw file):

	log.SetExitFunc(false, func(_ exit.Code) {
		if hasExited.Get() {
			t.Fatalf("multiple log.Fatal calls encountered")

t.Errorf? Or is this called from the main goroutine? If so a comment might be helpful.

Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @rauchenstein and @tbg)

pkg/rpc/context.go, line 1198 at r2 (raw file):

no it doesn't make a difference in this case because err is not nil

however, we've been pretty consistent throughout the code base recommending %v for errors instead of %s and I'm pushing it here now for consistency.

pkg/rpc/heartbeat_test.go, line 161 at r1 (raw file):

t.Errorf is right, good call. It happens to be called from the main goroutine but we shouldn't rely on it.
Added a comment to explain the purpose too.