Fix roster fallback bug causing PID mapping corruption after pmm-agen…

managed/services/agents/handler.go

@@ -180,6 +180,9 @@ func (h *Handler) stateChanged(ctx context.Context, req *agentv1.StateChangedReq
 		req.AgentId = strings.TrimPrefix(req.AgentId, "/agent_id/")
 		PMMAgentID, agentIDs, err = h.r.roster.get(req.AgentId)
 		if err != nil {
+			// Roster entry missing - trigger state refresh to rebuild roster
+			logger.Get(ctx).Warnf("Roster entry not found for %s, triggering state refresh: %v", req.AgentId, err)
+			h.state.RequestStateUpdate(ctx, PMMAgentID)
 			return err
 		}
 

managed/services/agents/roster.go

@@ -20,6 +20,7 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"gopkg.in/reform.v1"
 
@@ -84,17 +85,7 @@ func (r *roster) get(groupID string) (string, []string, error) {
 		if !ok {
 			agentIDs = []string{PMMAgentID}
 		} else {
-			rdsExporterType := models.RDSExporterType
-			awsAccessKey := strings.TrimPrefix(parts[1], rdsPrefix)
-			filters := models.AgentFilters{PMMAgentID: PMMAgentID, AgentType: &rdsExporterType, AWSAccessKey: awsAccessKey}
-			agents, err := models.FindAgents(r.db.Querier, filters)
-			if err != nil {
-				return "", nil, err
-			}
-			agentIDs = make([]string, 0, len(agents))
-			for _, agent := range agents {
-				agentIDs = append(agentIDs, agent.AgentID)
-			}
+			return "", nil, errors.Errorf("roster entry not found for groupID: %s", groupID)
 		}
 	}
 

managed/services/agents/roster_test.go

@@ -79,9 +79,10 @@ func TestRoster(t *testing.T) {
 		const groupID = "pmm-server:rds/AWSAccessKey"
 
 		PMMAgentID, agentIDs, err := r.get(groupID)
-		require.NoError(t, err)
-		assert.Equal(t, "pmm-server", PMMAgentID)
-		assert.Equal(t, []string{}, agentIDs)
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "roster entry not found")
+		assert.Equal(t, "", PMMAgentID)
+		assert.Nil(t, agentIDs)
 	})
 
 	t.Run("Clear", func(t *testing.T) {
@@ -110,8 +111,9 @@ func TestRoster(t *testing.T) {
 		r.clear(PMMAgentID)
 		PMMAgentID, agentIDs, err := r.get(groupID)
 
-		require.NoError(t, err)
-		assert.Equal(t, "pmm-server", PMMAgentID)
-		assert.Equal(t, []string{}, agentIDs)
+		require.Error(t, err)
+		assert.Contains(t, err.Error(), "roster entry not found")
+		assert.Equal(t, "", PMMAgentID)
+		assert.Nil(t, agentIDs)
 	})
 }