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Check RowsAffected when applying DML events to get more accurate statistics #844

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Merged
timvaillancourt merged 5 commits into from
Jul 14, 2021
Merged

Check RowsAffected when applying DML events to get more accurate statistics #844

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0670246
Check RowsAffected when applying DML events to get more accurate stat…
May 10, 2020
b8593a6
Merge branch 'master' into dml_rowcounts
timvaillancourt Jul 4, 2021
c02832b
Fix import
timvaillancourt Jul 4, 2021
80597ce
update wording to warning log message
ajm188 Jul 12, 2021
bfda007
Merge branch 'master' into dml_rowcounts
timvaillancourt Jul 14, 2021
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18 changes: 14 additions & 4 deletions go/logic/applier.go
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Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
Copyright 2016 GitHub Inc.
Copyright 2021 GitHub Inc.
See https://github.com/github/gh-ost/blob/master/LICENSE
*/

Expand All @@ -8,6 +8,7 @@ package logic
import (
gosql "database/sql"
"fmt"
"sync"
"sync/atomic"
"time"

Expand All @@ -16,8 +17,8 @@ import (
"github.com/github/gh-ost/go/mysql"
"github.com/github/gh-ost/go/sql"

"github.com/openark/golib/log"
"github.com/openark/golib/sqlutils"
"sync"
)

const (
Expand Down Expand Up @@ -1043,11 +1044,20 @@ func (this *Applier) ApplyDMLEventQueries(dmlEvents [](*binlog.BinlogDMLEvent))
if buildResult.err != nil {
return rollback(buildResult.err)
}
if _, err := tx.Exec(buildResult.query, buildResult.args...); err != nil {
result, err := tx.Exec(buildResult.query, buildResult.args...)
if err != nil {
err = fmt.Errorf("%s; query=%s; args=%+v", err.Error(), buildResult.query, buildResult.args)
return rollback(err)
}
totalDelta += buildResult.rowsDelta

rowsAffected, err := result.RowsAffected()
if err != nil {
log.Warningf("error getting rows affected from DML event query: %s. i'm going to assume that the DML affected a single row, but this may result in inaccurate statistics", err)
rowsAffected = 1
}
// each DML is either a single insert (delta +1), update (delta +0) or delete (delta -1).
// multiplying by the rows actually affected (either 0 or 1) will give an accurate row delta for this DML event
totalDelta += buildResult.rowsDelta * rowsAffected
}
}
if err := tx.Commit(); err != nil {
Expand Down