frostfs-node/pkg/local_object_storage/writecache/writecachebadger/flush.go
Anton Nikiforov 4dff9555f1 [#568] writecache: Improve flushing scheme for badger
Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>
2023-08-30 17:22:28 +00:00

282 lines
7.2 KiB
Go

package writecachebadger
import (
"bytes"
"context"
"encoding/hex"
"errors"
"fmt"
"time"
"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
objectCore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor"
"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/internal/metaerr"
meta "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/metabase"
"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
"git.frostfs.info/TrueCloudLab/frostfs-observability/tracing"
objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
"github.com/dgraph-io/badger/v4"
"github.com/dgraph-io/ristretto/z"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/trace"
"go.uber.org/zap"
)
const (
// flushBatchSize is amount of keys which will be read from cache to be flushed
// to the main storage. It is used to reduce contention between cache put
// and cache persist.
flushBatchSize = 512
// defaultFlushWorkersCount is number of workers for putting objects in main storage.
defaultFlushWorkersCount = 20
// defaultFlushInterval is default time interval between successive flushes.
defaultFlushInterval = time.Second
)
type collector struct {
cache *cache
scheduled int
processed int
cancel func()
}
func (c *collector) Send(buf *z.Buffer) error {
list, err := badger.BufferToKVList(buf)
if err != nil {
return err
}
for _, kv := range list.Kv {
select {
case <-c.cache.closeCh:
c.cancel()
return nil
default:
}
if kv.StreamDone {
return nil
}
if c.scheduled >= flushBatchSize {
c.cancel()
return nil
}
if got, want := len(kv.Key), len(internalKey{}); got != want {
c.cache.log.Debug(
fmt.Sprintf("not expected db key len: got %d, want %d", got, want))
continue
}
c.processed++
obj := objectSDK.New()
val := bytes.Clone(kv.Value)
if err = obj.Unmarshal(val); err != nil {
continue
}
addr := objectCore.AddressOf(obj)
c.cache.scheduled4FlushMtx.RLock()
_, ok := c.cache.scheduled4Flush[addr]
c.cache.scheduled4FlushMtx.RUnlock()
if ok {
c.cache.log.Debug(logs.WritecacheBadgerObjAlreadyScheduled, zap.Stringer("obj", addr))
continue
}
c.cache.scheduled4FlushMtx.Lock()
c.cache.scheduled4Flush[addr] = struct{}{}
c.cache.scheduled4FlushMtx.Unlock()
c.scheduled++
select {
case c.cache.flushCh <- obj:
case <-c.cache.closeCh:
c.cancel()
return nil
}
}
return nil
}
// runFlushLoop starts background workers which periodically flush objects to the blobstor.
func (c *cache) runFlushLoop() {
for i := 0; i < c.workersCount; i++ {
c.wg.Add(1)
go c.workerFlushSmall()
}
c.wg.Add(1)
go func() {
defer c.wg.Done()
tt := time.NewTimer(defaultFlushInterval)
defer tt.Stop()
for {
select {
case <-tt.C:
c.flushSmallObjects()
tt.Reset(defaultFlushInterval)
case <-c.closeCh:
return
}
}
}()
}
func (c *cache) flushSmallObjects() {
for {
select {
case <-c.closeCh:
return
default:
}
c.modeMtx.RLock()
if c.readOnly() {
c.modeMtx.RUnlock()
time.Sleep(time.Second)
continue
}
// Using the db after Close will panic and badger won't wait for outstanding txs,
// so we need to check manually.
if c.db.IsClosed() {
c.modeMtx.RUnlock()
return
}
ctx, cancel := context.WithCancel(context.TODO())
coll := collector{
cache: c,
cancel: cancel,
}
stream := c.db.NewStream()
// All calls to Send are done by a single goroutine
stream.Send = coll.Send
if err := stream.Orchestrate(ctx); err != nil {
c.log.Debug(fmt.Sprintf(
"error during flushing object from wc: %s", err))
}
c.modeMtx.RUnlock()
if coll.scheduled == 0 {
break
}
c.log.Debug(logs.WritecacheTriedToFlushItemsFromWritecache,
zap.Int("scheduled", coll.scheduled), zap.Int("processed", coll.processed))
}
}
func (c *cache) reportFlushError(msg string, addr string, err error) {
if c.reportError != nil {
c.reportError(msg, err)
} else {
c.log.Error(msg,
zap.String("address", addr),
zap.Error(err))
}
}
// workerFlushSmall writes small objects to the main storage.
func (c *cache) workerFlushSmall() {
defer c.wg.Done()
var obj *objectSDK.Object
for {
// Give priority to direct put.
select {
case obj = <-c.flushCh:
case <-c.closeCh:
return
}
addr := objectCore.AddressOf(obj)
err := c.flushObject(context.TODO(), obj, nil, writecache.StorageTypeDB)
if err == nil {
c.deleteFromDB([]internalKey{addr2key(addr)})
}
c.scheduled4FlushMtx.Lock()
delete(c.scheduled4Flush, addr)
c.scheduled4FlushMtx.Unlock()
}
}
// flushObject is used to write object directly to the main storage.
func (c *cache) flushObject(ctx context.Context, obj *objectSDK.Object, data []byte, st writecache.StorageType) error {
var err error
defer func() {
c.metrics.Flush(err == nil, st)
}()
addr := objectCore.AddressOf(obj)
var prm common.PutPrm
prm.Object = obj
prm.RawData = data
res, err := c.blobstor.Put(ctx, prm)
if err != nil {
if !errors.Is(err, common.ErrNoSpace) && !errors.Is(err, common.ErrReadOnly) &&
!errors.Is(err, blobstor.ErrNoPlaceFound) {
c.reportFlushError(logs.FrostFSNodeCantFlushObjectToBlobstor,
addr.EncodeToString(), err)
}
return err
}
var updPrm meta.UpdateStorageIDPrm
updPrm.SetAddress(addr)
updPrm.SetStorageID(res.StorageID)
_, err = c.metabase.UpdateStorageID(updPrm)
if err != nil {
c.reportFlushError(logs.FrostFSNodeCantUpdateObjectStorageID,
addr.EncodeToString(), err)
}
return err
}
// Flush flushes all objects from the write-cache to the main storage.
// Write-cache must be in readonly mode to ensure correctness of an operation and
// to prevent interference with background flush workers.
func (c *cache) Flush(ctx context.Context, ignoreErrors bool) error {
ctx, span := tracing.StartSpanFromContext(ctx, "writecache.Flush",
trace.WithAttributes(
attribute.Bool("ignore_errors", ignoreErrors),
))
defer span.End()
c.modeMtx.RLock()
defer c.modeMtx.RUnlock()
return c.flush(ctx, ignoreErrors)
}
func (c *cache) flush(ctx context.Context, ignoreErrors bool) error {
return c.db.View(func(tx *badger.Txn) error {
it := tx.NewIterator(badger.DefaultIteratorOptions)
defer it.Close()
var key internalKey
for it.Rewind(); it.Valid(); it.Next() {
if got, want := int(it.Item().KeySize()), len(key); got != want {
err := fmt.Errorf("invalid db key len: got %d, want %d", got, want)
c.reportFlushError(logs.FrostFSNodeCantDecodeObjectAddressFromDB, hex.EncodeToString(it.Item().Key()), metaerr.Wrap(err))
if ignoreErrors {
continue
}
return err
}
if err := it.Item().Value(func(data []byte) error {
var obj objectSDK.Object
if err := obj.Unmarshal(data); err != nil {
copy(key[:], it.Item().Key())
c.reportFlushError(logs.FrostFSNodeCantUnmarshalObjectFromDB, key.address().EncodeToString(), metaerr.Wrap(err))
if ignoreErrors {
return nil
}
return err
}
return c.flushObject(ctx, &obj, data, writecache.StorageTypeDB)
}); err != nil {
return err
}
}
return nil
})
}