plugeth/core/rawdb/chain_freezer.go
Martin Holst Swende 0b53b29078
core/rawdb: fix cornercase shutdown behaviour in freezer (#26485)
This PR does a few things. 
It fixes a shutdown-order flaw in the chainfreezer. Previously, the chain-freezer would shutdown the freezer backend first, and then signal for the loop to exit. This can lead to a scenario where the freezer tries to fsync closed files, which is an error-conditon that could lead to exit via log.Crit. 

It also makes the printout more detailed when truncating 'dangling' items, by showing the exact number instead of approximate MB.

This PR also adds calls to fsync files before closing them, and also makes the `db inspect` command slightly more robust.
2023-01-16 03:57:27 -05:00

306 lines
9.8 KiB
Go

// Copyright 2022 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package rawdb
import (
"fmt"
"sync"
"sync/atomic"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/params"
)
const (
// freezerRecheckInterval is the frequency to check the key-value database for
// chain progression that might permit new blocks to be frozen into immutable
// storage.
freezerRecheckInterval = time.Minute
// freezerBatchLimit is the maximum number of blocks to freeze in one batch
// before doing an fsync and deleting it from the key-value store.
freezerBatchLimit = 30000
)
// chainFreezer is a wrapper of freezer with additional chain freezing feature.
// The background thread will keep moving ancient chain segments from key-value
// database to flat files for saving space on live database.
type chainFreezer struct {
// WARNING: The `threshold` field is accessed atomically. On 32 bit platforms, only
// 64-bit aligned fields can be atomic. The struct is guaranteed to be so aligned,
// so take advantage of that (https://golang.org/pkg/sync/atomic/#pkg-note-BUG).
threshold uint64 // Number of recent blocks not to freeze (params.FullImmutabilityThreshold apart from tests)
*Freezer
quit chan struct{}
wg sync.WaitGroup
trigger chan chan struct{} // Manual blocking freeze trigger, test determinism
}
// newChainFreezer initializes the freezer for ancient chain data.
func newChainFreezer(datadir string, namespace string, readonly bool, maxTableSize uint32, tables map[string]bool) (*chainFreezer, error) {
freezer, err := NewFreezer(datadir, namespace, readonly, maxTableSize, tables)
if err != nil {
return nil, err
}
return &chainFreezer{
Freezer: freezer,
threshold: params.FullImmutabilityThreshold,
quit: make(chan struct{}),
trigger: make(chan chan struct{}),
}, nil
}
// Close closes the chain freezer instance and terminates the background thread.
func (f *chainFreezer) Close() error {
select {
case <-f.quit:
default:
close(f.quit)
}
f.wg.Wait()
return f.Freezer.Close()
}
// freeze is a background thread that periodically checks the blockchain for any
// import progress and moves ancient data from the fast database into the freezer.
//
// This functionality is deliberately broken off from block importing to avoid
// incurring additional data shuffling delays on block propagation.
func (f *chainFreezer) freeze(db ethdb.KeyValueStore) {
var (
backoff bool
triggered chan struct{} // Used in tests
nfdb = &nofreezedb{KeyValueStore: db}
)
timer := time.NewTimer(freezerRecheckInterval)
defer timer.Stop()
for {
select {
case <-f.quit:
log.Info("Freezer shutting down")
return
default:
}
if backoff {
// If we were doing a manual trigger, notify it
if triggered != nil {
triggered <- struct{}{}
triggered = nil
}
select {
case <-timer.C:
backoff = false
timer.Reset(freezerRecheckInterval)
case triggered = <-f.trigger:
backoff = false
case <-f.quit:
return
}
}
// Retrieve the freezing threshold.
hash := ReadHeadBlockHash(nfdb)
if hash == (common.Hash{}) {
log.Debug("Current full block hash unavailable") // new chain, empty database
backoff = true
continue
}
number := ReadHeaderNumber(nfdb, hash)
threshold := atomic.LoadUint64(&f.threshold)
frozen := atomic.LoadUint64(&f.frozen)
switch {
case number == nil:
log.Error("Current full block number unavailable", "hash", hash)
backoff = true
continue
case *number < threshold:
log.Debug("Current full block not old enough", "number", *number, "hash", hash, "delay", threshold)
backoff = true
continue
case *number-threshold <= frozen:
log.Debug("Ancient blocks frozen already", "number", *number, "hash", hash, "frozen", frozen)
backoff = true
continue
}
head := ReadHeader(nfdb, hash, *number)
if head == nil {
log.Error("Current full block unavailable", "number", *number, "hash", hash)
backoff = true
continue
}
// Seems we have data ready to be frozen, process in usable batches
var (
start = time.Now()
first, _ = f.Ancients()
limit = *number - threshold
)
if limit-first > freezerBatchLimit {
limit = first + freezerBatchLimit
}
ancients, err := f.freezeRange(nfdb, first, limit)
if err != nil {
log.Error("Error in block freeze operation", "err", err)
backoff = true
continue
}
// Batch of blocks have been frozen, flush them before wiping from leveldb
if err := f.Sync(); err != nil {
log.Crit("Failed to flush frozen tables", "err", err)
}
// Wipe out all data from the active database
batch := db.NewBatch()
for i := 0; i < len(ancients); i++ {
// Always keep the genesis block in active database
if first+uint64(i) != 0 {
DeleteBlockWithoutNumber(batch, ancients[i], first+uint64(i))
DeleteCanonicalHash(batch, first+uint64(i))
}
}
if err := batch.Write(); err != nil {
log.Crit("Failed to delete frozen canonical blocks", "err", err)
}
batch.Reset()
// Wipe out side chains also and track dangling side chains
var dangling []common.Hash
frozen = atomic.LoadUint64(&f.frozen) // Needs reload after during freezeRange
for number := first; number < frozen; number++ {
// Always keep the genesis block in active database
if number != 0 {
dangling = ReadAllHashes(db, number)
for _, hash := range dangling {
log.Trace("Deleting side chain", "number", number, "hash", hash)
DeleteBlock(batch, hash, number)
}
}
}
if err := batch.Write(); err != nil {
log.Crit("Failed to delete frozen side blocks", "err", err)
}
batch.Reset()
// Step into the future and delete and dangling side chains
if frozen > 0 {
tip := frozen
for len(dangling) > 0 {
drop := make(map[common.Hash]struct{})
for _, hash := range dangling {
log.Debug("Dangling parent from Freezer", "number", tip-1, "hash", hash)
drop[hash] = struct{}{}
}
children := ReadAllHashes(db, tip)
for i := 0; i < len(children); i++ {
// Dig up the child and ensure it's dangling
child := ReadHeader(nfdb, children[i], tip)
if child == nil {
log.Error("Missing dangling header", "number", tip, "hash", children[i])
continue
}
if _, ok := drop[child.ParentHash]; !ok {
children = append(children[:i], children[i+1:]...)
i--
continue
}
// Delete all block data associated with the child
log.Debug("Deleting dangling block", "number", tip, "hash", children[i], "parent", child.ParentHash)
DeleteBlock(batch, children[i], tip)
}
dangling = children
tip++
}
if err := batch.Write(); err != nil {
log.Crit("Failed to delete dangling side blocks", "err", err)
}
}
// Log something friendly for the user
context := []interface{}{
"blocks", frozen - first, "elapsed", common.PrettyDuration(time.Since(start)), "number", frozen - 1,
}
if n := len(ancients); n > 0 {
context = append(context, []interface{}{"hash", ancients[n-1]}...)
}
log.Debug("Deep froze chain segment", context...)
// Avoid database thrashing with tiny writes
if frozen-first < freezerBatchLimit {
backoff = true
}
}
}
func (f *chainFreezer) freezeRange(nfdb *nofreezedb, number, limit uint64) (hashes []common.Hash, err error) {
hashes = make([]common.Hash, 0, limit-number)
_, err = f.ModifyAncients(func(op ethdb.AncientWriteOp) error {
for ; number <= limit; number++ {
// Retrieve all the components of the canonical block.
hash := ReadCanonicalHash(nfdb, number)
if hash == (common.Hash{}) {
return fmt.Errorf("canonical hash missing, can't freeze block %d", number)
}
header := ReadHeaderRLP(nfdb, hash, number)
if len(header) == 0 {
return fmt.Errorf("block header missing, can't freeze block %d", number)
}
body := ReadBodyRLP(nfdb, hash, number)
if len(body) == 0 {
return fmt.Errorf("block body missing, can't freeze block %d", number)
}
receipts := ReadReceiptsRLP(nfdb, hash, number)
if len(receipts) == 0 {
return fmt.Errorf("block receipts missing, can't freeze block %d", number)
}
td := ReadTdRLP(nfdb, hash, number)
if len(td) == 0 {
return fmt.Errorf("total difficulty missing, can't freeze block %d", number)
}
// Write to the batch.
if err := op.AppendRaw(chainFreezerHashTable, number, hash[:]); err != nil {
return fmt.Errorf("can't write hash to Freezer: %v", err)
}
if err := op.AppendRaw(chainFreezerHeaderTable, number, header); err != nil {
return fmt.Errorf("can't write header to Freezer: %v", err)
}
if err := op.AppendRaw(chainFreezerBodiesTable, number, body); err != nil {
return fmt.Errorf("can't write body to Freezer: %v", err)
}
if err := op.AppendRaw(chainFreezerReceiptTable, number, receipts); err != nil {
return fmt.Errorf("can't write receipts to Freezer: %v", err)
}
if err := op.AppendRaw(chainFreezerDifficultyTable, number, td); err != nil {
return fmt.Errorf("can't write td to Freezer: %v", err)
}
hashes = append(hashes, hash)
}
return nil
})
return hashes, err
}