func (m *mfileBlock) WriteBuf(_ context.Context, s torus.BlockRef) ([]byte, error) {
m.mut.Lock()
defer m.mut.Unlock()
if m.closed {
promBlockWritesFailed.WithLabelValues(m.name).Inc()
return nil, torus.ErrClosed
}
index := m.findEmpty()
if index == -1 {
clog.Error("mfile: out of space")
promBlockWritesFailed.WithLabelValues(m.name).Inc()
return nil, torus.ErrOutOfSpace
}
clog.Tracef("mfile: writing block at index %d", index)
buf := m.dataFile.GetBlock(uint64(index))
err := m.refFile.WriteBlock(uint64(index), s.ToBytes())
if err != nil {
promBlockWritesFailed.WithLabelValues(m.name).Inc()
return nil, err
}
if v := m.findIndex(s); v != -1 {
// we already have it
clog.Debug("mfile: block already exists", s)
// Not an error, if we already have it
return nil, torus.ErrExists
}
promBlocks.WithLabelValues(m.name).Inc()
m.refIndex[s] = index
promBlocksWritten.WithLabelValues(m.name).Inc()
return buf, nil
}
func (k *ketama) GetPeers(key torus.BlockRef) (torus.PeerPermutation, error) {
s, ok := k.ring.GetNodes(string(key.ToBytes()), len(k.peers))
if !ok {
if len(s) == 0 {
return torus.PeerPermutation{}, errors.New("couldn't get any nodes")
}
for _, x := range k.peers {
has := false
for _, y := range s {
if y == x.UUID {
has = true
break
}
}
if !has {
s = append(s, x.UUID)
}
}
}
if len(s) != len(k.peers) {
return torus.PeerPermutation{}, errors.New("couldn't get sufficient nodes")
}
rep := k.rep
if len(k.peers) < k.rep {
rep = len(k.peers)
}
return torus.PeerPermutation{
Peers: s,
Replication: rep,
}, nil
}
func (d *Distributor) readFromPeer(ctx context.Context, i torus.BlockRef, peer string) ([]byte, error) {
blk, err := d.client.GetBlock(ctx, peer, i)
// If we're successful, store that.
if err == nil {
d.readCache.Put(string(i.ToBytes()), blk)
promDistBlockPeerHits.WithLabelValues(peer).Inc()
return blk, nil
}
return nil, err
}
func (m *mod) GetPeers(key torus.BlockRef) (torus.PeerPermutation, error) {
permute := make([]string, len(m.peerlist))
crc := crc32.ChecksumIEEE(key.ToBytes())
sum := int(crc) % len(m.peers)
copy(permute, m.peerlist[sum:])
copy(permute[len(m.peerlist)-sum:], m.peerlist[:sum])
return torus.PeerPermutation{
Peers: permute,
Replication: m.rep,
}, nil
}
func (d *Distributor) GetBlock(ctx context.Context, i torus.BlockRef) ([]byte, error) {
d.mut.RLock()
defer d.mut.RUnlock()
promDistBlockRequests.Inc()
bcache, ok := d.readCache.Get(string(i.ToBytes()))
if ok {
promDistBlockCacheHits.Inc()
return bcache.([]byte), nil
}
peers, err := d.ring.GetPeers(i)
if err != nil {
promDistBlockFailures.Inc()
return nil, err
}
if len(peers.Peers) == 0 {
promDistBlockFailures.Inc()
return nil, ErrNoPeersBlock
}
writeLevel := d.getWriteFromServer()
for _, p := range peers.Peers[:peers.Replication] {
if p == d.UUID() || writeLevel == torus.WriteLocal {
b, err := d.blocks.GetBlock(ctx, i)
if err == nil {
promDistBlockLocalHits.Inc()
return b, nil
}
promDistBlockLocalFailures.Inc()
break
}
}
var blk []byte
readLevel := d.getReadFromServer()
switch readLevel {
case torus.ReadBlock:
blk, err = d.readWithBackoff(ctx, i, peers)
case torus.ReadSequential:
blk, err = d.readSequential(ctx, i, peers, clientTimeout)
case torus.ReadSpread:
blk, err = d.readSpread(ctx, i, peers)
default:
panic("unhandled read level")
}
if err != nil {
// We completely failed!
promDistBlockFailures.Inc()
clog.Errorf("no peers for block %s", i)
}
return blk, err
}
func (m *mfileBlock) WriteBlock(_ context.Context, s torus.BlockRef, data []byte) error {
m.mut.Lock()
defer m.mut.Unlock()
if m.closed {
promBlockWritesFailed.WithLabelValues(m.name).Inc()
return torus.ErrClosed
}
index := m.findEmpty()
if index == -1 {
clog.Error("mfile: out of space")
promBlockWritesFailed.WithLabelValues(m.name).Inc()
return torus.ErrOutOfSpace
}
clog.Tracef("mfile: writing block at index %d", index)
err := m.dataFile.WriteBlock(uint64(index), data)
if err != nil {
promBlockWritesFailed.WithLabelValues(m.name).Inc()
return err
}
err = m.refFile.WriteBlock(uint64(index), s.ToBytes())
if err != nil {
promBlockWritesFailed.WithLabelValues(m.name).Inc()
return err
}
if v := m.findIndex(s); v != -1 {
// we already have it
clog.Debug("mfile: block already exists", s)
olddata := m.dataFile.GetBlock(uint64(v))
if !bytes.Equal(olddata, data) {
clog.Error("getting wrong data for block", s)
clog.Errorf("%s, %s", olddata[:10], data[:10])
return torus.ErrExists
}
// Not an error, if we already have it
return nil
}
promBlocks.WithLabelValues(m.name).Inc()
m.refIndex[s] = index
promBlocksWritten.WithLabelValues(m.name).Inc()
return nil
}
func (m *mod) GetPeers(key torus.BlockRef) (torus.PeerPermutation, error) {
peerlist := sort.StringSlice([]string(m.peers.PeerList()))
if len(peerlist) == 0 {
return torus.PeerPermutation{}, fmt.Errorf("couldn't get any nodes")
}
if len(peerlist) != len(m.peers) {
return torus.PeerPermutation{}, fmt.Errorf("couldn't get sufficient nodes")
}
permute := make([]string, len(peerlist))
crc := crc32.ChecksumIEEE(key.ToBytes())
sum := int(crc) % len(m.peers)
copy(permute, peerlist[sum:])
copy(permute[len(peerlist)-sum:], peerlist[:sum])
rep := m.rep
if len(m.peers) < m.rep {
rep = len(m.peers)
}
return torus.PeerPermutation{
Peers: permute,
Replication: rep,
}, nil
}
func (d *Distributor) WriteBlock(ctx context.Context, i torus.BlockRef, data []byte) error {
d.mut.RLock()
defer d.mut.RUnlock()
peers, err := d.ring.GetPeers(i)
if err != nil {
return err
}
if len(peers.Peers) == 0 {
return torus.ErrOutOfSpace
}
d.readCache.Put(string(i.ToBytes()), data)
switch d.getWriteFromServer() {
case torus.WriteLocal:
err = d.blocks.WriteBlock(ctx, i, data)
if err == nil {
return nil
}
clog.Tracef("Couldn't write locally; writing to cluster")
fallthrough
case torus.WriteOne:
for _, p := range peers.Peers[:peers.Replication] {
// If we're one of the desired peers, we count, write here first.
if p == d.UUID() {
err = d.blocks.WriteBlock(ctx, i, data)
if err != nil {
clog.Noticef("WriteOne error, local: %s", err)
} else {
return nil
}
}
}
for _, p := range peers.Peers {
err = d.client.PutBlock(ctx, p, i, data)
if err == nil {
return nil
}
clog.Noticef("WriteOne error, remote: %s", err)
}
return torus.ErrNoPeer
case torus.WriteAll:
toWrite := peers.Replication
for _, p := range peers.Peers {
var err error
if p == d.UUID() {
err = d.blocks.WriteBlock(ctx, i, data)
} else {
err = d.client.PutBlock(ctx, p, i, data)
}
if err != nil {
clog.Noticef("error WriteAll to peer %s: %s", p, err)
} else {
toWrite--
}
if toWrite == 0 {
return nil
}
}
if toWrite == peers.Replication {
clog.Noticef("error WriteAll to all peers")
return torus.ErrNoPeer
}
clog.Warningf("only wrote block to %d/%d peers", toWrite, peers.Replication)
}
return nil
}