handle edge condition on recoonect - repeated network errors while parsing same long transaction (go-mysql-org#438)

gleonid · siddontang · commit fba9c9655f7c · 2019-10-19T10:59:32.000+08:00
diff --git a/replication/binlogsyncer.go b/replication/binlogsyncer.go
@@ -761,7 +761,10 @@ func (b *BinlogSyncer) parseEvent(s *BinlogStreamer, data []byte) error {
 		prev := b.currGset.Clone()
 		err := b.currGset.Update(gtid)
 		if err == nil {
-			b.prevGset = prev
+			// right after reconnect we will see same gtid as we saw before, thus currGset will not get changed
+			if !b.currGset.Equal(prev) {
+				b.prevGset = prev
+			}
 		}
 		return err
 	}

Original file line number	Diff line number	Diff line change
`@@ -761,7 +761,10 @@ func (b BinlogSyncer) parseEvent(s BinlogStreamer, data []byte) error {`
`761`	`761`	`prev := b.currGset.Clone()`
`762`	`762`	`err := b.currGset.Update(gtid)`
`763`	`763`	`if err == nil {`
`764`		`- b.prevGset = prev`
	`764`	`+ // right after reconnect we will see same gtid as we saw before, thus currGset will not get changed`
	`765`	`+ if !b.currGset.Equal(prev) {`
	`766`	`+ b.prevGset = prev`
	`767`	`+ }`
`765`	`768`	`}`
`766`	`769`	`return err`
`767`	`770`	`}`