From 4b452d8a3ade0a65994a0020b22d11899a009503 Mon Sep 17 00:00:00 2001
From: Jaynti Kanani <jdkanani@gmail.com>
Date: Tue, 3 Dec 2019 16:47:28 +0530
Subject: [PATCH] retry span and states in bor

---
 consensus/bor/bor.go  |  6 ++---
 consensus/bor/rest.go | 56 +++++++++++++++++++++++++++++++++----------
 2 files changed, 46 insertions(+), 16 deletions(-)

diff --git a/consensus/bor/bor.go b/consensus/bor/bor.go
index dd7cee90ea..a622f0d7d0 100644
--- a/consensus/bor/bor.go
+++ b/consensus/bor/bor.go
@@ -17,7 +17,7 @@ import (
 	"sync"
 	"time"
 
-	"github.com/maticnetwork/bor"
+	ethereum "github.com/maticnetwork/bor"
 	"github.com/maticnetwork/bor/accounts"
 	"github.com/maticnetwork/bor/accounts/abi"
 	"github.com/maticnetwork/bor/common"
@@ -1038,7 +1038,7 @@ func (c *Bor) commitSpan(
 	header *types.Header,
 	chain core.ChainContext,
 ) error {
-	response, err := FetchFromHeimdall(c.httpClient, c.chainConfig.Bor.Heimdall, "bor", "span", strconv.FormatUint(span.ID+1, 10))
+	response, err := FetchFromHeimdallWithRetry(c.httpClient, c.chainConfig.Bor.Heimdall, "bor", "span", strconv.FormatUint(span.ID+1, 10))
 	if err != nil {
 		return err
 	}
@@ -1158,7 +1158,7 @@ func (c *Bor) CommitStates(
 	// itereate through state ids
 	for _, stateID := range stateIds {
 		// fetch from heimdall
-		response, err := FetchFromHeimdall(c.httpClient, c.chainConfig.Bor.Heimdall, "clerk", "event-record", strconv.FormatUint(stateID.Uint64(), 10))
+		response, err := FetchFromHeimdallWithRetry(c.httpClient, c.chainConfig.Bor.Heimdall, "clerk", "event-record", strconv.FormatUint(stateID.Uint64(), 10))
 		if err != nil {
 			return err
 		}
diff --git a/consensus/bor/rest.go b/consensus/bor/rest.go
index f855adc992..d68c70304e 100644
--- a/consensus/bor/rest.go
+++ b/consensus/bor/rest.go
@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"net/url"
 	"path"
+	"time"
 )
 
 // ResponseWithHeight defines a response object type that wraps an original
@@ -16,19 +17,8 @@ type ResponseWithHeight struct {
 	Result json.RawMessage `json:"result"`
 }
 
-// FetchFromHeimdall returns data from heimdall
-func FetchFromHeimdall(client http.Client, urlString string, paths ...string) (*ResponseWithHeight, error) {
-	u, err := url.Parse(urlString)
-	if err != nil {
-		return nil, err
-	}
-
-	for _, e := range paths {
-		if e != "" {
-			u.Path = path.Join(u.Path, e)
-		}
-	}
-
+// internal fetch method
+func internalFetch(client http.Client, u *url.URL) (*ResponseWithHeight, error) {
 	res, err := client.Get(u.String())
 	if err != nil {
 		return nil, err
@@ -54,3 +44,43 @@ func FetchFromHeimdall(client http.Client, urlString string, paths ...string) (*
 
 	return &response, nil
 }
+
+// FetchFromHeimdallWithRetry returns data from heimdall with retry
+func FetchFromHeimdallWithRetry(client http.Client, urlString string, paths ...string) (*ResponseWithHeight, error) {
+	u, err := url.Parse(urlString)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, e := range paths {
+		if e != "" {
+			u.Path = path.Join(u.Path, e)
+		}
+	}
+
+	for {
+		res, err := internalFetch(client, u)
+		if err == nil && res != nil {
+			return res, nil
+		}
+		fmt.Println("Retrying again in 5 seconds", u.String())
+		time.Sleep(5 * time.Second)
+
+	}
+}
+
+// FetchFromHeimdall returns data from heimdall
+func FetchFromHeimdall(client http.Client, urlString string, paths ...string) (*ResponseWithHeight, error) {
+	u, err := url.Parse(urlString)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, e := range paths {
+		if e != "" {
+			u.Path = path.Join(u.Path, e)
+		}
+	}
+
+	return internalFetch(client, u)
+}