From d1028fd621438d92d5748db4e853b2fa5aac6684 Mon Sep 17 00:00:00 2001
From: chenxiaobin <1025221611@qq.com>
Date: Sun, 25 Apr 2021 10:15:03 +0800
Subject: [PATCH] fixbug: divided by zero

---
 src/gausskernel/storage/replication/walsender.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/gausskernel/storage/replication/walsender.cpp b/src/gausskernel/storage/replication/walsender.cpp
index 13bc3992f..181a938da 100644
--- a/src/gausskernel/storage/replication/walsender.cpp
+++ b/src/gausskernel/storage/replication/walsender.cpp
@@ -5493,7 +5493,8 @@ static void CalCatchupRate() {
         SpinLockRelease(&walsnd->mutex);
         return;
     }
-    if (TimestampDifferenceExceeds(walsnd->lastCalTime, now, CALCULATE_CATCHUP_RATE_TIME)) {
+    if (TimestampDifferenceExceeds(walsnd->lastCalTime, now, CALCULATE_CATCHUP_RATE_TIME) &&
+        XLByteLT(walsnd->lastCalWrite, write)) {
         double tempRate = (double)(now - walsnd->lastCalTime) /
                           (double)XLByteDifference(write, walsnd->lastCalWrite);
         walsnd->catchupRate = walsnd->catchupRate == 0 ? tempRate : (walsnd->catchupRate + tempRate) / 2;