frostfs-node/pkg/local_object_storage/writecache/flush.go
Anton Nikiforov 3195142d67 [#959] writecache: Avoid manipulation with cache in DEGRADED mode
Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>
2024-03-11 18:35:41 +00:00

373 lines
8.3 KiB
Go

package writecache
import (
"bytes"
"context"
"errors"
"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/shard/mode"
"git.frostfs.info/TrueCloudLab/frostfs-observability/tracing"
objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
"github.com/mr-tron/base58"
"go.etcd.io/bbolt"
"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
)
var errIterationCompleted = errors.New("iteration completed")
// runFlushLoop starts background workers which periodically flush objects to the blobstor.
func (c *cache) runFlushLoop(ctx context.Context) {
if c.disableBackgroundFlush {
return
}
for i := 0; i < c.workersCount; i++ {
c.wg.Add(1)
go c.workerFlushSmall(ctx)
}
c.wg.Add(1)
go func() {
c.workerFlushBig(ctx)
c.wg.Done()
}()
c.wg.Add(1)
go func() {
defer c.wg.Done()
tt := time.NewTimer(defaultFlushInterval)
defer tt.Stop()
for {
select {
case <-tt.C:
c.flushSmallObjects(ctx)
tt.Reset(defaultFlushInterval)
c.estimateCacheSize()
case <-ctx.Done():
return
}
}
}()
}
func (c *cache) flushSmallObjects(ctx context.Context) {
var lastKey []byte
for {
select {
case <-ctx.Done():
return
default:
}
var m []objectInfo
c.modeMtx.RLock()
if c.readOnly() {
c.modeMtx.RUnlock()
time.Sleep(time.Second)
continue
}
// We put objects in batches of fixed size to not interfere with main put cycle a lot.
_ = c.db.View(func(tx *bbolt.Tx) error {
b := tx.Bucket(defaultBucket)
cs := b.Cursor()
var k, v []byte
if len(lastKey) == 0 {
k, v = cs.First()
} else {
k, v = cs.Seek(lastKey)
if bytes.Equal(k, lastKey) {
k, v = cs.Next()
}
}
for ; k != nil && len(m) < flushBatchSize; k, v = cs.Next() {
if len(lastKey) == len(k) {
copy(lastKey, k)
} else {
lastKey = bytes.Clone(k)
}
m = append(m, objectInfo{
addr: string(k),
data: bytes.Clone(v),
})
}
return nil
})
var count int
for i := range m {
obj := objectSDK.New()
if err := obj.Unmarshal(m[i].data); err != nil {
continue
}
m[i].obj = obj
count++
select {
case c.flushCh <- m[i]:
case <-ctx.Done():
c.modeMtx.RUnlock()
return
}
}
c.modeMtx.RUnlock()
if count == 0 {
break
}
c.log.Debug(logs.WritecacheTriedToFlushItemsFromWritecache,
zap.Int("count", count),
zap.String("start", base58.Encode(lastKey)))
}
}
func (c *cache) workerFlushBig(ctx context.Context) {
tick := time.NewTicker(defaultFlushInterval * 10)
for {
select {
case <-tick.C:
c.modeMtx.RLock()
if c.readOnly() || c.noMetabase() {
c.modeMtx.RUnlock()
break
}
_ = c.flushFSTree(ctx, true)
c.modeMtx.RUnlock()
case <-ctx.Done():
return
}
}
}
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))
}
}
func (c *cache) flushFSTree(ctx context.Context, ignoreErrors bool) error {
var prm common.IteratePrm
prm.IgnoreErrors = ignoreErrors
prm.Handler = func(e common.IterationElement) error {
sAddr := e.Address.EncodeToString()
var obj objectSDK.Object
err := obj.Unmarshal(e.ObjectData)
if err != nil {
c.reportFlushError(logs.FSTreeCantUnmarshalObject, sAddr, metaerr.Wrap(err))
if ignoreErrors {
return nil
}
return err
}
err = c.flushObject(ctx, &obj, e.ObjectData, StorageTypeFSTree)
if err != nil {
if ignoreErrors {
return nil
}
return err
}
c.deleteFromDisk(ctx, e.Address)
return nil
}
_, err := c.fsTree.Iterate(ctx, prm)
return err
}
// workerFlushSmall writes small objects to the main storage.
func (c *cache) workerFlushSmall(ctx context.Context) {
defer c.wg.Done()
var objInfo objectInfo
for {
// Give priority to direct put.
select {
case objInfo = <-c.flushCh:
case <-ctx.Done():
return
}
err := c.flushObject(ctx, objInfo.obj, objInfo.data, StorageTypeDB)
if err != nil {
// Error is handled in flushObject.
continue
}
c.deleteFromDB(objInfo.addr, true)
}
}
// flushObject is used to write object directly to the main storage.
func (c *cache) flushObject(ctx context.Context, obj *objectSDK.Object, data []byte, st 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.FSTreeCantFushObjectBlobstor,
addr.EncodeToString(), err)
}
return err
}
var updPrm meta.UpdateStorageIDPrm
updPrm.SetAddress(addr)
updPrm.SetStorageID(res.StorageID)
_, err = c.metabase.UpdateStorageID(ctx, updPrm)
if err != nil {
c.reportFlushError(logs.FSTreeCantUpdateID,
addr.EncodeToString(), err)
}
return err
}
// Flush flushes all objects from the write-cache to the main storage.
func (c *cache) Flush(ctx context.Context, ignoreErrors, seal bool) error {
ctx, span := tracing.StartSpanFromContext(ctx, "writecache.Flush",
trace.WithAttributes(
attribute.Bool("ignore_errors", ignoreErrors),
attribute.Bool("seal", seal),
))
defer span.End()
c.modeMtx.Lock() // exclusive lock to not to conflict with background flush
defer c.modeMtx.Unlock()
if c.noMetabase() {
return ErrDegraded
}
if err := c.flush(ctx, ignoreErrors); err != nil {
return err
}
if seal {
m := c.mode | mode.ReadOnly
if err := c.setMode(ctx, m, ignoreErrors); err != nil {
return err
}
c.metrics.SetMode(m)
}
return nil
}
func (c *cache) flush(ctx context.Context, ignoreErrors bool) error {
if err := c.flushFSTree(ctx, ignoreErrors); err != nil {
return err
}
var last string
for {
batch, err := c.readNextDBBatch(ignoreErrors, last)
if err != nil {
return err
}
if len(batch) == 0 {
break
}
for _, item := range batch {
var obj objectSDK.Object
if err := obj.Unmarshal(item.data); err != nil {
c.reportFlushError(logs.FSTreeCantDecodeDBObjectAddress, item.address, metaerr.Wrap(err))
if ignoreErrors {
continue
}
return err
}
if err := c.flushObject(ctx, &obj, item.data, StorageTypeDB); err != nil {
return err
}
c.deleteFromDB(item.address, false)
}
last = batch[len(batch)-1].address
}
return nil
}
type batchItem struct {
data []byte
address string
}
func (c *cache) readNextDBBatch(ignoreErrors bool, last string) ([]batchItem, error) {
const batchSize = 100
var batch []batchItem
err := c.db.View(func(tx *bbolt.Tx) error {
var addr oid.Address
b := tx.Bucket(defaultBucket)
cs := b.Cursor()
for k, data := cs.Seek([]byte(last)); k != nil; k, data = cs.Next() {
sa := string(k)
if sa == last {
continue
}
if err := addr.DecodeString(sa); err != nil {
c.reportFlushError(logs.FSTreeCantDecodeDBObjectAddress, sa, metaerr.Wrap(err))
if ignoreErrors {
continue
}
return err
}
batch = append(batch, batchItem{data: bytes.Clone(data), address: sa})
if len(batch) == batchSize {
return errIterationCompleted
}
}
return nil
})
if err == nil || errors.Is(err, errIterationCompleted) {
return batch, nil
}
return nil, err
}