[BUG]: Badger expired data is still there(using txn.Get(k) ). after a restart or several days running.
Author: winjegCreated Dec 18, 2024Updated Jul 27, 2026
Labelskind/bugStale
What version of Badger are you using?
github.com/dgraph-io/badger/v4 v4.2.0
What version of Go are you using?
go 1.22.0 toolchain go1.22.4
Have you tried reproducing the issue with the latest release?
No
What is the hardware spec (RAM, CPU, OS)?
16Core CPU. 64GB Ram , Linux
What steps will reproduce the bug?
I am not completely sure about how to reproduce the bug. It will appear after I run several hours or days badger operation. After a restart, some of the expired keys is still there when I scan the related keys or get the key directly.
Can someone give me a bit of advice or guidance? Thanks.
Pseudocode：
func writeData(k1, k2, k3[]byte) {
txn := tu.db.NewTransaction(true)
defer txn.Discard()
k1DataV1 := txn.Get(k1)
k1DataV2 := processK1(k1DataV1)
txn.set(k1, k1DataV2)
k2DataV1 := txn.Get(k2)
k2DataV2 := processK1(k2DataV1)
txn.set(k2, k2DataV2)
k3DataV1 := txn.Get(k3)
k3DataV2 := processK1(k3DataV1)
txn.set(k3, k3DataV2)
txn.setWithTTL(k2, k2DataV3, time.Second * 300)
}Expected behavior and actual result.
Expired data should not be accessable via the basic get or scan APIs of badgerdb.
Should return key not found like errors.
Additional information
shutdown is called when the program caught kill signal.
The sync error log didn't appear.
The Server exiting end --- log appeared.
shutdown code
func BadgerClose() {
for _, v := range defaultMgr.instances {
if v != nil {
if syncErr := v.Sync(); syncErr != nil {
logger.Errorf("sync error:%+v\n", syncErr)
}
err := v.Close()
if err != nil {
logger.Errorln(err.Error())
}
}
}
}
func shutdown() {
BadgerClose()
logger.Info("Server exiting end ---------------- ")
}
badger options
opts := badger.DefaultOptions(getPath(badgerCfg.BasePath, key))
opts = opts.WithLogger(logger)
opts = opts.WithMetricsEnabled(true)
opts = opts.WithNumMemtables(badgerCfg.MemTableNum)
opts = opts.WithMemTableSize(badgerCfg.MemTableSize << 20)
opts = opts.WithNumLevelZeroTables(8)
opts = opts.WithNumCompactors(4)
opts = opts.WithValueLogFileSize(128 << 20)
opts = opts.WithCompactL0OnClose(true)
db, err := badger.Open(opts)
Source: dgraph-io/badger