Is this a BUG REPORT or FEATURE REQUEST?:

Uncomment only one, leave it on its own line:

• bug

What happened:
备节点使用gs_basebackup备份失败，提示could not fetch mot checkpoint info: , status:7

What you expected to happen:

How to reproduce it (as minimally and precisely as possible):
一主两备, 仅发生一次，无法复现
1.备节点执行备份指令
gs_basebackup -D xxx -h xxx -p xxx -v -t 3600
2.备节点执行备份的同时停止主节点
gs_ctl stop -D xxx
3.检查备份结果
备份异常打印：
keepalive message is received
transaction log end point:76/B3000370
gs_basebackup: fetching MOT checkpoint
gs_basebackup: could not fetch mot checkpoint info:, status:7

Anything else we need to know?:

Environment:

• Version:
• OS (e.g. from /etc/os-release):
• Kernel (e.g. uname -a):
• Install tools:
• Others: