minResolvedTS: Provide an API to fetch the store resolved_ts (#6413)

server/api/min_resolved_ts.go

@@ -16,7 +16,9 @@ package api
 
 import (
 	"net/http"
+	"strconv"
 
+	"github.com/gorilla/mux"
 	"github.com/tikv/pd/pkg/typeutil"
 	"github.com/tikv/pd/server"
 	"github.com/unrolled/render"
@@ -41,6 +43,30 @@ type minResolvedTS struct {
 	PersistInterval typeutil.Duration `json:"persist_interval,omitempty"`
 }
 
+// @Tags     min_store_resolved_ts
+// @Summary  Get store-level min resolved ts.
+// @Produce  json
+// @Success  200  {array}   minResolvedTS
+// @Failure  400  {string}  string  "The input is invalid."
+// @Failure  500  {string}  string  "PD server failed to proceed the request."
+// @Router   /min-resolved-ts/{store_id} [get]
+func (h *minResolvedTSHandler) GetStoreMinResolvedTS(w http.ResponseWriter, r *http.Request) {
+	c := h.svr.GetRaftCluster()
+	idStr := mux.Vars(r)["store_id"]
+	storeID, err := strconv.ParseUint(idStr, 10, 64)
+	if err != nil {
+		h.rd.JSON(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	value := c.GetStoreMinResolvedTS(storeID)
+	persistInterval := c.GetOpts().GetPDServerConfig().MinResolvedTSPersistenceInterval
+	h.rd.JSON(w, http.StatusOK, minResolvedTS{
+		MinResolvedTS:   value,
+		PersistInterval: persistInterval,
+		IsRealTime:      persistInterval.Duration != 0,
+	})
+}
+
 // @Tags     min_resolved_ts
 // @Summary  Get cluster-level min resolved ts.
 // @Produce  json

server/api/router.go

@@ -351,6 +351,7 @@ func createRouter(prefix string, svr *server.Server) *mux.Router {
 	// min resolved ts API
 	minResolvedTSHandler := newMinResolvedTSHandler(svr, rd)
 	registerFunc(clusterRouter, "/min-resolved-ts", minResolvedTSHandler.GetMinResolvedTS, setMethods(http.MethodGet), setAuditBackend(prometheus))
+	registerFunc(clusterRouter, "/min-resolved-ts/{store_id}", minResolvedTSHandler.GetStoreMinResolvedTS, setMethods(http.MethodGet), setAuditBackend(prometheus))
 
 	// unsafe admin operation API
 	unsafeOperationHandler := newUnsafeOperationHandler(svr, rd)

server/cluster/cluster.go

@@ -2308,6 +2308,16 @@ func (c *RaftCluster) GetMinResolvedTS() uint64 {
 	return c.minResolvedTS
 }
 
+// GetStoreMinResolvedTS returns the min resolved ts of the store.
+func (c *RaftCluster) GetStoreMinResolvedTS(storeID uint64) uint64 {
+	c.RLock()
+	defer c.RUnlock()
+	if !c.isInitialized() || !core.IsAvailableForMinResolvedTS(c.GetStore(storeID)) {
+		return math.MaxUint64
+	}
+	return c.GetStore(storeID).GetMinResolvedTS()
+}
+
 // GetExternalTS returns the external timestamp.
 func (c *RaftCluster) GetExternalTS() uint64 {
 	c.RLock()