Skip to content

fix: stop sending DeleteTailnetPeer when coordinator is unhealthy #12925

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Apr 10, 2024
Merged

fix: stop sending DeleteTailnetPeer when coordinator is unhealthy #12925

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
24 changes: 23 additions & 1 deletion enterprise/tailnet/pgcoord.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -231,6 +231,17 @@ func (c *pgCoord) Coordinate(
logger := c.logger.With(slog.F("peer_id", id))
reqs := make(chan *proto.CoordinateRequest, agpl.RequestBufferSize)
resps := make(chan *proto.CoordinateResponse, agpl.ResponseBufferSize)
if !c.querier.isHealthy() {
// If the coordinator is unhealthy, we don't want to hook this Coordinate call up to the
// binder, as that can cause an unnecessary call to DeleteTailnetPeer when the connIO is
// closed. Instead, we just close the response channel and bail out.
// c.f. https://github.com/coder/coder/issues/12923
c.logger.Info(ctx, "closed incoming coordinate call while unhealthy",
slog.F("peer_id", id),
)
close(resps)
return reqs, resps
}
cIO := newConnIO(c.ctx, ctx, logger, c.bindings, c.tunnelerCh, reqs, resps, id, name, a)
err := agpl.SendCtx(c.ctx, c.newConnections, cIO)
if err != nil {
Expand Down Expand Up @@ -842,7 +853,12 @@ func (q *querier) newConn(c *connIO) {
defer q.mu.Unlock()
if !q.healthy {
err := c.Close()
q.logger.Info(q.ctx, "closed incoming connection while unhealthy",
// This can only happen during a narrow window where we were healthy
// when pgCoord checked before accepting the connection, but now are
// unhealthy now that we get around to processing it. Seeing a small
// number of these logs is not worrying, but a large number probably
// indicates something is amiss.
q.logger.Warn(q.ctx, "closed incoming connection while unhealthy",
slog.Error(err),
slog.F("peer_id", c.UniqueID()),
)
Expand All @@ -865,6 +881,12 @@ func (q *querier) newConn(c *connIO) {
})
}

func (q *querier) isHealthy() bool {
q.mu.Lock()
defer q.mu.Unlock()
return q.healthy
}

func (q *querier) cleanupConn(c *connIO) {
logger := q.logger.With(slog.F("peer_id", c.UniqueID()))
q.mu.Lock()
Expand Down
51 changes: 51 additions & 0 deletions enterprise/tailnet/pgcoord_internal_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@ import (
"github.com/google/uuid"
"github.com/stretchr/testify/require"
"go.uber.org/mock/gomock"
"golang.org/x/xerrors"
gProto "google.golang.org/protobuf/proto"

"cdr.dev/slog"
Expand All @@ -21,6 +22,8 @@ import (
"github.com/coder/coder/v2/coderd/database"
"github.com/coder/coder/v2/coderd/database/dbmock"
"github.com/coder/coder/v2/coderd/database/dbtestutil"
"github.com/coder/coder/v2/coderd/database/pubsub"
agpl "github.com/coder/coder/v2/tailnet"
"github.com/coder/coder/v2/tailnet/proto"
"github.com/coder/coder/v2/testutil"
)
Expand Down Expand Up @@ -291,3 +294,51 @@ func TestGetDebug(t *testing.T) {
require.Equal(t, peerID, debug.Tunnels[0].SrcID)
require.Equal(t, dstID, debug.Tunnels[0].DstID)
}

// TestPGCoordinatorUnhealthy tests that when the coordinator fails to send heartbeats and is
// unhealthy it disconnects any peers and does not send any extraneous database queries.
func TestPGCoordinatorUnhealthy(t *testing.T) {
t.Parallel()
ctx := testutil.Context(t, testutil.WaitShort)
logger := slogtest.Make(t, &slogtest.Options{IgnoreErrors: true}).Leveled(slog.LevelDebug)

ctrl := gomock.NewController(t)
mStore := dbmock.NewMockStore(ctrl)
ps := pubsub.NewInMemory()

// after 3 failed heartbeats, the coordinator is unhealthy
mStore.EXPECT().
UpsertTailnetCoordinator(gomock.Any(), gomock.Any()).
MinTimes(3).
Return(database.TailnetCoordinator{}, xerrors.New("badness"))
mStore.EXPECT().
DeleteCoordinator(gomock.Any(), gomock.Any()).
Times(1).
Return(nil)
// But, in particular we DO NOT want the coordinator to call DeleteTailnetPeer, as this is
// unnecessary and can spam the database. c.f. https://github.com/coder/coder/issues/12923

// these cleanup queries run, but we don't care for this test
mStore.EXPECT().CleanTailnetCoordinators(gomock.Any()).AnyTimes().Return(nil)
mStore.EXPECT().CleanTailnetLostPeers(gomock.Any()).AnyTimes().Return(nil)
mStore.EXPECT().CleanTailnetTunnels(gomock.Any()).AnyTimes().Return(nil)

coordinator, err := newPGCoordInternal(ctx, logger, ps, mStore)
require.NoError(t, err)

require.Eventually(t, func() bool {
return !coordinator.querier.isHealthy()
}, testutil.WaitShort, testutil.IntervalFast)

pID := uuid.UUID{5}
_, resps := coordinator.Coordinate(ctx, pID, "test", agpl.AgentCoordinateeAuth{ID: pID})
resp := testutil.RequireRecvCtx(ctx, t, resps)
require.Nil(t, resp, "channel should be closed")

// give the coordinator some time to process any pending work. We are
// testing here that a database call is absent, so we don't want to race to
// shut down the test.
time.Sleep(testutil.IntervalMedium)
_ = coordinator.Close()
require.Eventually(t, ctrl.Satisfied, testutil.WaitShort, testutil.IntervalFast)
}
Loading