copr: Fix bug that mpp node availability detect does not work in some corner cases (#28201)
copr: Fix bug that mpp node availability detect does not work in some corner cases (#28201)

 
kyle-wang/tidb,c4pt0r/tidb,ngaut/tidb,ngaut/tidb,kyle-wang/tidb,ngaut/tidb,coocood/tidb,c4pt0r/tidb,pingcap/tidb,kyle-wang/tidb,kyle-wang/tidb,kyle-wang/tidb,c4pt0r/tidb,pingcap/tidb,c4pt0r/tidb,c4pt0r/tidb,pingcap/tidb,ngaut/tidb,coocood/tidb,ngaut/tidb,ngaut/tidb,kyle-wang/tidb,pingcap/tidb,pingcap/tidb,c4pt0r/tidb,pingcap/tidb