bisync: Graceful Shutdown, --recover from interruptions without --resync - fixes #7470

Before this change, bisync had no mechanism to gracefully cancel a sync early
and exit in a clean state. Additionally, there was no way to recover on the
next run -- any interruption at all would cause bisync to require a --resync,
which made  bisync more difficult to use as a scheduled background process.

This change introduces a "Graceful Shutdown" mode and --recover flag to
robustly recover from even un-graceful shutdowns.

If --recover is set, in the event of a sudden interruption or other un-graceful
shutdown, bisync will attempt to automatically recover on the next run, instead
of requiring --resync. Bisync is able to recover robustly by keeping one
"backup" listing at all times, representing the state of both paths after the
last known successful sync. Bisync can then compare the current state with this
snapshot to determine which changes it needs to retry. Changes that were synced
after this snapshot (during the run that was later interrupted) will appear to
bisync as if they are "new or changed on both sides", but in most cases this is
not a problem, as bisync will simply do its usual "equality check" and learn
that no action needs to be taken on these files, since they are already
identical on both sides.

In the rare event that a file is synced successfully during a run that later
aborts, and then that same file changes AGAIN before the next run, bisync will
think it is a sync conflict, and handle it accordingly. (From bisync's
perspective, the file has changed on both sides since the last trusted sync,
and the files on either side are not currently identical.) Therefore, --recover
carries with it a slightly increased chance of having conflicts -- though in
practice this is pretty rare, as the conditions required to cause it are quite
specific. This risk can be reduced by using bisync's "Graceful Shutdown" mode
(triggered by sending SIGINT or Ctrl+C), when you have the choice, instead of
forcing a sudden termination.

--recover and --resilient are similar, but distinct -- the main difference is
that --resilient is about _retrying_, while --recover is about _recovering_.
Most users will probably want both. --resilient allows retrying when bisync has
chosen to abort itself due to safety features such as failing --check-access or
detecting a filter change. --resilient does not cover external interruptions
such as a user shutting down their computer in the middle of a sync -- that is
what --recover is for.

"Graceful Shutdown" mode is activated by sending SIGINT or pressing Ctrl+C
during a run. Once triggered, bisync will use best efforts to exit cleanly
before the timer runs out. If bisync is in the middle of transferring files, it
will attempt to cleanly empty its queue by finishing what it has started but
not taking more. If it cannot do so within 30 seconds, it will cancel the
in-progress transfers at that point and then give itself a maximum of 60
seconds to wrap up, save its state for next time, and exit. With the -vP flags
you will see constant status updates and a final confirmation of whether or not
the graceful shutdown was successful.

At any point during the "Graceful Shutdown" sequence, a second SIGINT or Ctrl+C
will trigger an immediate, un-graceful exit, which will leave things in a
messier state. Usually a robust recovery will still be possible if using
--recover mode, otherwise you will need to do a --resync.

If you plan to use Graceful Shutdown mode, it is recommended to use --resilient
and --recover, and it is important to NOT use --inplace, otherwise you risk
leaving partially-written files on one side, which may be confused for real
files on the next run. Note also that in the event of an abrupt interruption, a
lock file will be left behind to block concurrent runs. You will need to delete
it before you can proceed with the next run (or wait for it to expire on its
own, if using --max-lock.)
This commit is contained in:
nielash 2023-12-03 00:38:18 -05:00
parent b4216648e4
commit 4025f42bd9
7 changed files with 394 additions and 54 deletions

View File

@ -48,10 +48,12 @@ type Options struct {
SaveQueues bool // save extra debugging files (test only flag)
IgnoreListingChecksum bool
Resilient bool
Recover bool
TestFn TestFunc // test-only option, for mocking errors
Retries int
Compare CompareOpt
CompareFlag string
DebugName string
}
// Default values
@ -125,10 +127,12 @@ func init() {
flags.StringVarP(cmdFlags, &Opt.Workdir, "workdir", "", Opt.Workdir, makeHelp("Use custom working dir - useful for testing. (default: {WORKDIR})"), "")
flags.StringVarP(cmdFlags, &Opt.BackupDir1, "backup-dir1", "", Opt.BackupDir1, "--backup-dir for Path1. Must be a non-overlapping path on the same remote.", "")
flags.StringVarP(cmdFlags, &Opt.BackupDir2, "backup-dir2", "", Opt.BackupDir2, "--backup-dir for Path2. Must be a non-overlapping path on the same remote.", "")
flags.StringVarP(cmdFlags, &Opt.DebugName, "debugname", "", Opt.DebugName, "Debug by tracking one file at various points throughout a bisync run (when -v or -vv)", "")
flags.BoolVarP(cmdFlags, &tzLocal, "localtime", "", tzLocal, "Use local time in listings (default: UTC)", "")
flags.BoolVarP(cmdFlags, &Opt.NoCleanup, "no-cleanup", "", Opt.NoCleanup, "Retain working files (useful for troubleshooting and testing).", "")
flags.BoolVarP(cmdFlags, &Opt.IgnoreListingChecksum, "ignore-listing-checksum", "", Opt.IgnoreListingChecksum, "Do not use checksums for listings (add --ignore-checksum to additionally skip post-copy checksum checks)", "")
flags.BoolVarP(cmdFlags, &Opt.Resilient, "resilient", "", Opt.Resilient, "Allow future runs to retry after certain less-serious errors, instead of requiring --resync. Use at your own risk!", "")
flags.BoolVarP(cmdFlags, &Opt.Recover, "recover", "", Opt.Recover, "Automatically recover from interruptions without requiring --resync.", "")
flags.IntVarP(cmdFlags, &Opt.Retries, "retries", "", Opt.Retries, "Retry operations this many times if they fail", "")
flags.StringVarP(cmdFlags, &Opt.CompareFlag, "compare", "", Opt.CompareFlag, "Comma-separated list of bisync-specific compare options ex. 'size,modtime,checksum' (default: 'size,modtime')", "")
flags.BoolVarP(cmdFlags, &Opt.Compare.NoSlowHash, "no-slow-hash", "", Opt.Compare.NoSlowHash, "Ignore listing checksums only on backends where they are slow", "")

View File

@ -387,9 +387,12 @@ func (b *bisyncRun) applyDeltas(ctx context.Context, ds1, ds2 *deltaSet) (change
//if files are identical, leave them alone instead of renaming
if (dirs1.has(file) || dirs1.has(alias)) && (dirs2.has(file) || dirs2.has(alias)) {
fs.Debugf(nil, "This is a directory, not a file. Skipping equality check and will not rename: %s", file)
fs.Infof(nil, "This is a directory, not a file. Skipping equality check and will not rename: %s", file)
ls1.getPut(file, skippedDirs1)
ls2.getPut(file, skippedDirs2)
b.debugFn(file, func() {
b.debug(file, fmt.Sprintf("deltas dir: %s, ls1 has name?: %v, ls2 has name?: %v", file, ls1.has(b.DebugName), ls2.has(b.DebugName)))
})
} else {
equal := matches.Has(file)
if !equal {
@ -499,7 +502,7 @@ func (b *bisyncRun) applyDeltas(ctx context.Context, ds1, ds2 *deltaSet) (change
}
// Do the batch operation
if copy2to1.NotEmpty() {
if copy2to1.NotEmpty() && !b.InGracefulShutdown {
changes1 = true
b.indent("Path2", "Path1", "Do queued copies to")
ctx = b.setBackupDir(ctx, 1)
@ -508,7 +511,7 @@ func (b *bisyncRun) applyDeltas(ctx context.Context, ds1, ds2 *deltaSet) (change
// retries, if any
results2to1, err = b.retryFastCopy(ctx, b.fs2, b.fs1, copy2to1, "copy2to1", results2to1, err)
if err != nil {
if !b.InGracefulShutdown && err != nil {
return
}
@ -516,7 +519,7 @@ func (b *bisyncRun) applyDeltas(ctx context.Context, ds1, ds2 *deltaSet) (change
b.syncEmptyDirs(ctx, b.fs1, copy2to1, dirs2, &results2to1, "make")
}
if copy1to2.NotEmpty() {
if copy1to2.NotEmpty() && !b.InGracefulShutdown {
changes2 = true
b.indent("Path1", "Path2", "Do queued copies to")
ctx = b.setBackupDir(ctx, 2)
@ -525,7 +528,7 @@ func (b *bisyncRun) applyDeltas(ctx context.Context, ds1, ds2 *deltaSet) (change
// retries, if any
results1to2, err = b.retryFastCopy(ctx, b.fs1, b.fs2, copy1to2, "copy1to2", results1to2, err)
if err != nil {
if !b.InGracefulShutdown && err != nil {
return
}
@ -533,7 +536,7 @@ func (b *bisyncRun) applyDeltas(ctx context.Context, ds1, ds2 *deltaSet) (change
b.syncEmptyDirs(ctx, b.fs2, copy1to2, dirs1, &results1to2, "make")
}
if delete1.NotEmpty() {
if delete1.NotEmpty() && !b.InGracefulShutdown {
if err = b.saveQueue(delete1, "delete1"); err != nil {
return
}
@ -541,7 +544,7 @@ func (b *bisyncRun) applyDeltas(ctx context.Context, ds1, ds2 *deltaSet) (change
b.syncEmptyDirs(ctx, b.fs1, delete1, dirs1, &results2to1, "remove")
}
if delete2.NotEmpty() {
if delete2.NotEmpty() && !b.InGracefulShutdown {
if err = b.saveQueue(delete2, "delete2"); err != nil {
return
}

View File

@ -17,6 +17,7 @@ import (
"github.com/rclone/rclone/cmd/bisync/bilib"
"github.com/rclone/rclone/fs"
"github.com/rclone/rclone/fs/accounting"
"github.com/rclone/rclone/fs/filter"
"github.com/rclone/rclone/fs/hash"
"github.com/rclone/rclone/fs/operations"
@ -368,6 +369,12 @@ func (b *bisyncRun) replaceCurrentListings() {
b.handleErr(b.newListing2, "error replacing Path2 listing", bilib.CopyFileIfExists(b.newListing2, b.listing2), true, true)
}
// revertToOldListings reverts to the most recent successful listing
func (b *bisyncRun) revertToOldListings() {
b.handleErr(b.listing1, "error reverting to old Path1 listing", bilib.CopyFileIfExists(b.listing1+"-old", b.listing1), true, true)
b.handleErr(b.listing2, "error reverting to old Path2 listing", bilib.CopyFileIfExists(b.listing2+"-old", b.listing2), true, true)
}
func parseHash(str string) (string, string, error) {
if str == "-" {
return "", "", nil
@ -498,6 +505,12 @@ func (b *bisyncRun) modifyListing(ctx context.Context, src fs.Fs, dst fs.Fs, res
}
}
b.debugFn(b.DebugName, func() {
var rs ResultsSlice = results
b.debug(b.DebugName, fmt.Sprintf("modifyListing direction: %s, results has name?: %v", direction, rs.has(b.DebugName)))
b.debug(b.DebugName, fmt.Sprintf("modifyListing direction: %s, srcList has name?: %v, dstList has name?: %v", direction, srcList.has(b.DebugName), dstList.has(b.DebugName)))
})
srcWinners := newFileList()
dstWinners := newFileList()
errors := newFileList()
@ -657,6 +670,55 @@ func (b *bisyncRun) modifyListing(ctx context.Context, src fs.Fs, dst fs.Fs, res
b.recheck(ctxRecheck, src, dst, srcList, dstList, is1to2)
}
if b.InGracefulShutdown {
var toKeep []string
var toRollback []string
fs.Debugf(direction, "stats for %s", direction)
trs := accounting.Stats(ctx).Transferred()
for _, tr := range trs {
b.debugFn(tr.Name, func() {
prettyprint(tr, tr.Name, fs.LogLevelInfo)
})
if tr.Error == nil && tr.Bytes > 0 || tr.Size <= 0 {
prettyprint(tr, "keeping: "+tr.Name, fs.LogLevelDebug)
toKeep = append(toKeep, tr.Name)
}
}
// Dirs (for the unlikely event that the shutdown was triggered post-sync during syncEmptyDirs)
for _, r := range results {
if r.Origin == "syncEmptyDirs" {
if srcWinners.has(r.Name) || dstWinners.has(r.Name) {
toKeep = append(toKeep, r.Name)
fs.Infof(r.Name, "keeping empty dir")
}
}
}
oldSrc, oldDst := b.getOldLists(is1to2)
prettyprint(oldSrc.list, "oldSrc", fs.LogLevelDebug)
prettyprint(oldDst.list, "oldDst", fs.LogLevelDebug)
prettyprint(srcList.list, "srcList", fs.LogLevelDebug)
prettyprint(dstList.list, "dstList", fs.LogLevelDebug)
combinedList := Concat(oldSrc.list, oldDst.list, srcList.list, dstList.list)
for _, f := range combinedList {
if !slices.Contains(toKeep, f) && !slices.Contains(toKeep, b.aliases.Alias(f)) && !b.opt.DryRun {
toRollback = append(toRollback, f)
}
}
b.prepareRollback(toRollback, srcList, dstList, is1to2)
prettyprint(oldSrc.list, "oldSrc", fs.LogLevelDebug)
prettyprint(oldDst.list, "oldDst", fs.LogLevelDebug)
prettyprint(srcList.list, "srcList", fs.LogLevelDebug)
prettyprint(dstList.list, "dstList", fs.LogLevelDebug)
// clear stats so we only do this once
accounting.MaxCompletedTransfers = 0
accounting.Stats(ctx).PruneTransfers()
}
if b.DebugName != "" {
b.debug(b.DebugName, fmt.Sprintf("%s pre-save srcList has it?: %v", direction, srcList.has(b.DebugName)))
b.debug(b.DebugName, fmt.Sprintf("%s pre-save dstList has it?: %v", direction, dstList.has(b.DebugName)))
}
// update files
err = srcList.save(ctx, srcListing)
b.handleErr(srcList, "error saving srcList from modifyListing", err, true, true)
@ -737,8 +799,8 @@ func (b *bisyncRun) recheck(ctxRecheck context.Context, src, dst fs.Fs, srcList,
}
for _, item := range toRollback {
rollback(item, oldSrc, srcList)
rollback(item, oldDst, dstList)
b.rollback(item, oldSrc, srcList)
b.rollback(item, oldDst, dstList)
}
}
}
@ -750,10 +812,72 @@ func (b *bisyncRun) getListingNames(is1to2 bool) (srcListing string, dstListing
return b.listing2, b.listing1
}
func rollback(item string, oldList, newList *fileList) {
func (b *bisyncRun) rollback(item string, oldList, newList *fileList) {
alias := b.aliases.Alias(item)
if oldList.has(item) {
oldList.getPut(item, newList)
fs.Debugf(nil, "adding to newlist: %s", item)
} else if oldList.has(alias) {
oldList.getPut(alias, newList)
fs.Debugf(nil, "adding to newlist: %s", alias)
} else {
fs.Debugf(nil, "removing from newlist: %s (has it?: %v)", item, newList.has(item))
prettyprint(newList.list, "newList", fs.LogLevelDebug)
newList.remove(item)
newList.remove(alias)
}
}
func (b *bisyncRun) prepareRollback(toRollback []string, srcList, dstList *fileList, is1to2 bool) {
if len(toRollback) > 0 {
oldSrc, oldDst := b.getOldLists(is1to2)
if b.critical {
return
}
fs.Debugf("new lists", "src: (%v), dest: (%v)", len(srcList.list), len(dstList.list))
for _, item := range toRollback {
b.debugFn(item, func() {
b.debug(item, fmt.Sprintf("pre-rollback oldSrc has it?: %v", oldSrc.has(item)))
b.debug(item, fmt.Sprintf("pre-rollback oldDst has it?: %v", oldDst.has(item)))
b.debug(item, fmt.Sprintf("pre-rollback srcList has it?: %v", srcList.has(item)))
b.debug(item, fmt.Sprintf("pre-rollback dstList has it?: %v", dstList.has(item)))
})
b.rollback(item, oldSrc, srcList)
b.rollback(item, oldDst, dstList)
b.debugFn(item, func() {
b.debug(item, fmt.Sprintf("post-rollback oldSrc has it?: %v", oldSrc.has(item)))
b.debug(item, fmt.Sprintf("post-rollback oldDst has it?: %v", oldDst.has(item)))
b.debug(item, fmt.Sprintf("post-rollback srcList has it?: %v", srcList.has(item)))
b.debug(item, fmt.Sprintf("post-rollback dstList has it?: %v", dstList.has(item)))
})
}
}
}
func (b *bisyncRun) getOldLists(is1to2 bool) (*fileList, *fileList) {
srcListing, dstListing := b.getListingNames(is1to2)
oldSrc, err := b.loadListing(srcListing + "-old")
b.handleErr(oldSrc, "error loading old src listing", err, true, true)
oldDst, err := b.loadListing(dstListing + "-old")
b.handleErr(oldDst, "error loading old dst listing", err, true, true)
fs.Debugf("get old lists", "is1to2: %v, oldsrc: %s (%v), olddest: %s (%v)", is1to2, srcListing+"-old", len(oldSrc.list), dstListing+"-old", len(oldDst.list))
return oldSrc, oldDst
}
// Concat returns a new slice concatenating the passed in slices.
func Concat[S ~[]E, E any](ss ...S) S {
size := 0
for _, s := range ss {
size += len(s)
if size < 0 {
panic("len out of range")
}
}
newslice := slices.Grow[S](nil, size)
for _, s := range ss {
newslice = append(newslice, s...)
}
return newslice
}

View File

@ -48,6 +48,7 @@ func (b *bisyncRun) makeMarchListing(ctx context.Context) (*fileList, *fileList,
if err != nil {
b.handleErr("march", "error during march", err, true, true)
b.abort = true
return ls1, ls2, err
}
// save files
@ -160,7 +161,7 @@ func (b *bisyncRun) ForObject(o fs.Object, isPath1 bool) {
if b.opt.Compare.Modtime {
modtime = o.ModTime(marchCtx).In(TZ)
}
id := "" // TODO
id := "" // TODO: ID(o)
flags := "-" // "-" for a file and "d" for a directory
marchLsLock.Lock()
ls.put(o.Remote(), o.Size(), modtime, hashVal, id, flags)
@ -235,3 +236,12 @@ func (b *bisyncRun) findCheckFiles(ctx context.Context) (*fileList, *fileList, e
return ls1, ls2, err
}
// ID returns the ID of the Object if known, or "" if not
func ID(o fs.Object) string {
do, ok := o.(fs.IDer)
if !ok {
return ""
}
return do.ID()
}

View File

@ -10,10 +10,13 @@ import (
"os"
"path/filepath"
"strconv"
"strings"
gosync "sync"
"time"
"github.com/rclone/rclone/cmd/bisync/bilib"
"github.com/rclone/rclone/fs"
"github.com/rclone/rclone/fs/accounting"
"github.com/rclone/rclone/fs/filter"
"github.com/rclone/rclone/fs/operations"
"github.com/rclone/rclone/lib/atexit"
@ -40,6 +43,11 @@ type bisyncRun struct {
opt *Options
octx context.Context
fctx context.Context
InGracefulShutdown bool
CleanupCompleted bool
SyncCI *fs.ConfigInfo
CancelSync context.CancelFunc
DebugName string
}
type queues struct {
@ -61,6 +69,7 @@ func Bisync(ctx context.Context, fs1, fs2 fs.Fs, optArg *Options) (err error) {
fs1: fs1,
fs2: fs2,
opt: &opt,
DebugName: opt.DebugName,
}
if opt.CheckFilename == "" {
@ -119,12 +128,53 @@ func Bisync(ctx context.Context, fs1, fs2 fs.Fs, optArg *Options) (err error) {
_ = os.Rename(file, failFile)
}
}
// waitFor runs fn() until it returns true or the timeout expires
waitFor := func(msg string, totalWait time.Duration, fn func() bool) (ok bool) {
const individualWait = 1 * time.Second
for i := 0; i < int(totalWait/individualWait); i++ {
ok = fn()
if ok {
return ok
}
fs.Infof(nil, Color(terminal.YellowFg, "%s: %v"), msg, int(totalWait/individualWait)-i)
time.Sleep(individualWait)
}
return false
}
finalise := func() {
finaliseOnce.Do(func() {
if atexit.Signalled() {
fs.Logf(nil, "Bisync interrupted. Must run --resync to recover.")
if b.opt.Resync {
fs.Logf(nil, Color(terminal.GreenFg, "No need to gracefully shutdown during --resync (just run it again.)"))
} else {
fs.Logf(nil, Color(terminal.YellowFg, "Attempting to gracefully shutdown. (Send exit signal again for immediate un-graceful shutdown.)"))
b.InGracefulShutdown = true
if b.SyncCI != nil {
fs.Infof(nil, Color(terminal.YellowFg, "Telling Sync to wrap up early."))
b.SyncCI.MaxTransfer = 1
b.SyncCI.MaxDuration = 1 * time.Second
b.SyncCI.CutoffMode = fs.CutoffModeSoft
gracePeriod := 30 * time.Second // TODO: flag to customize this?
if !waitFor("Canceling Sync if not done in", gracePeriod, func() bool { return b.CleanupCompleted }) {
fs.Logf(nil, Color(terminal.YellowFg, "Canceling sync and cleaning up"))
b.CancelSync()
waitFor("Aborting Bisync if not done in", 60*time.Second, func() bool { return b.CleanupCompleted })
}
} else {
// we haven't started to sync yet, so we're good.
// no need to worry about the listing files, as we haven't overwritten them yet.
b.CleanupCompleted = true
fs.Logf(nil, Color(terminal.GreenFg, "Graceful shutdown completed successfully."))
}
}
if !b.CleanupCompleted {
if !b.opt.Resync {
fs.Logf(nil, Color(terminal.HiRedFg, "Graceful shutdown failed."))
fs.Logf(nil, Color(terminal.RedFg, "Bisync interrupted. Must run --resync to recover."))
}
markFailed(b.listing1)
markFailed(b.listing2)
}
_ = os.Remove(lockFile)
}
})
@ -146,6 +196,17 @@ func Bisync(ctx context.Context, fs1, fs2 fs.Fs, optArg *Options) (err error) {
}
}
b.CleanupCompleted = true
if b.InGracefulShutdown {
if err == context.Canceled || err == accounting.ErrorMaxTransferLimitReachedGraceful {
err = nil
b.critical = false
}
if err == nil {
fs.Logf(nil, Color(terminal.GreenFg, "Graceful shutdown completed successfully."))
}
}
if b.critical {
if b.retryable && b.opt.Resilient {
fs.Errorf(nil, Color(terminal.RedFg, "Bisync critical error: %v"), err)
@ -162,7 +223,7 @@ func Bisync(ctx context.Context, fs1, fs2 fs.Fs, optArg *Options) (err error) {
}
return ErrBisyncAborted
}
if b.abort {
if b.abort && !b.InGracefulShutdown {
fs.Logf(nil, Color(terminal.RedFg, "Bisync aborted. Please try again."))
}
if err == nil {
@ -221,6 +282,22 @@ func (b *bisyncRun) runLocked(octx context.Context) (err error) {
// Check for existence of prior Path1 and Path2 listings
if !bilib.FileExists(b.listing1) || !bilib.FileExists(b.listing2) {
if b.opt.Recover && bilib.FileExists(b.listing1+"-old") && bilib.FileExists(b.listing2+"-old") {
errTip := fmt.Sprintf(Color(terminal.CyanFg, "Path1: %s\n"), Color(terminal.HiBlueFg, b.listing1))
errTip += fmt.Sprintf(Color(terminal.CyanFg, "Path2: %s"), Color(terminal.HiBlueFg, b.listing2))
fs.Logf(nil, Color(terminal.YellowFg, "Listings not found. Reverting to prior backup as --recover is set. \n")+errTip)
if opt.CheckSync != CheckSyncFalse {
// Run CheckSync to ensure old listing is valid (garbage in, garbage out!)
fs.Infof(nil, "Validating backup listings for Path1 %s vs Path2 %s", quotePath(path1), quotePath(path2))
if err = b.checkSync(b.listing1+"-old", b.listing2+"-old"); err != nil {
b.critical = true
b.retryable = true
return err
}
fs.Infof(nil, Color(terminal.GreenFg, "Backup listing is valid."))
}
b.revertToOldListings()
} else {
// On prior critical error abort, the prior listings are renamed to .lst-err to lock out further runs
b.critical = true
b.retryable = true
@ -232,10 +309,14 @@ func (b *bisyncRun) runLocked(octx context.Context) (err error) {
return errors.New("cannot find prior Path1 or Path2 listings, likely due to critical error on prior run \n" + errTip)
}
}
fs.Infof(nil, "Building Path1 and Path2 listings")
ls1, ls2, err = b.makeMarchListing(fctx)
if err != nil {
if err != nil || accounting.Stats(fctx).Errored() {
fs.Errorf(nil, Color(terminal.RedFg, "There were errors while building listings. Aborting as it is too dangerous to continue."))
b.critical = true
b.retryable = true
return err
}
@ -306,31 +387,50 @@ func (b *bisyncRun) runLocked(octx context.Context) (err error) {
fs.Infof(nil, "Applying changes")
changes1, changes2, results2to1, results1to2, queues, err = b.applyDeltas(octx, ds1, ds2)
if err != nil {
if b.InGracefulShutdown && (err == context.Canceled || err == accounting.ErrorMaxTransferLimitReachedGraceful || strings.Contains(err.Error(), "context canceled")) {
fs.Infof(nil, "Ignoring sync error due to Graceful Shutdown: %v", err)
} else {
b.critical = true
// b.retryable = true // not sure about this one
return err
}
}
}
// Clean up and check listings integrity
fs.Infof(nil, "Updating listings")
var err1, err2 error
if b.DebugName != "" {
l1, _ := b.loadListing(b.listing1)
l2, _ := b.loadListing(b.listing2)
newl1, _ := b.loadListing(b.newListing1)
newl2, _ := b.loadListing(b.newListing2)
b.debug(b.DebugName, fmt.Sprintf("pre-saveOldListings, ls1 has name?: %v, ls2 has name?: %v", l1.has(b.DebugName), l2.has(b.DebugName)))
b.debug(b.DebugName, fmt.Sprintf("pre-saveOldListings, newls1 has name?: %v, newls2 has name?: %v", newl1.has(b.DebugName), newl2.has(b.DebugName)))
}
b.saveOldListings()
// save new listings
// NOTE: "changes" in this case does not mean this run vs. last run, it means start of this run vs. end of this run.
// i.e. whether we can use the March lst-new as this side's lst without modifying it.
if noChanges {
b.replaceCurrentListings()
} else {
if changes1 { // 2to1
if changes1 || b.InGracefulShutdown { // 2to1
err1 = b.modifyListing(fctx, b.fs2, b.fs1, results2to1, queues, false)
} else {
err1 = bilib.CopyFileIfExists(b.newListing1, b.listing1)
}
if changes2 { // 1to2
if changes2 || b.InGracefulShutdown { // 1to2
err2 = b.modifyListing(fctx, b.fs1, b.fs2, results1to2, queues, true)
} else {
err2 = bilib.CopyFileIfExists(b.newListing2, b.listing2)
}
}
if b.DebugName != "" {
l1, _ := b.loadListing(b.listing1)
l2, _ := b.loadListing(b.listing2)
b.debug(b.DebugName, fmt.Sprintf("post-modifyListing, ls1 has name?: %v, ls2 has name?: %v", l1.has(b.DebugName), l2.has(b.DebugName)))
}
err = err1
if err == nil {
err = err2
@ -609,6 +709,18 @@ func (b *bisyncRun) setBackupDir(ctx context.Context, destPath int) context.Cont
return ctx
}
func (b *bisyncRun) debug(nametocheck, msgiftrue string) {
if b.DebugName != "" && b.DebugName == nametocheck {
fs.Infof(Color(terminal.MagentaBg, "DEBUGNAME "+b.DebugName), Color(terminal.MagentaBg, msgiftrue))
}
}
func (b *bisyncRun) debugFn(nametocheck string, fn func()) {
if b.DebugName != "" && b.DebugName == nametocheck {
fn()
}
}
// mainly to make sure tests don't interfere with each other when running more than one
func resetGlobals() {
downloadHash = false

View File

@ -11,6 +11,7 @@ import (
"github.com/rclone/rclone/cmd/bisync/bilib"
"github.com/rclone/rclone/fs"
"github.com/rclone/rclone/fs/accounting"
"github.com/rclone/rclone/fs/filter"
"github.com/rclone/rclone/fs/hash"
"github.com/rclone/rclone/fs/operations"
@ -35,6 +36,19 @@ type Results struct {
IsWinner bool
IsSrc bool
IsDst bool
Origin string
}
// ResultsSlice is a slice of Results (obviously)
type ResultsSlice []Results
func (rs *ResultsSlice) has(name string) bool {
for _, r := range *rs {
if r.Name == name {
return true
}
}
return false
}
var logger = operations.NewLoggerOpt()
@ -100,6 +114,7 @@ func WriteResults(ctx context.Context, sigil operations.Sigil, src, dst fs.DirEn
Src: FsPathIfAny(src),
Dst: FsPathIfAny(dst),
Err: err,
Origin: "sync",
}
result.Winner = operations.WinningSide(ctx, sigil, src, dst, err)
@ -202,6 +217,9 @@ func (b *bisyncRun) preCopy(ctx context.Context) context.Context {
}
func (b *bisyncRun) fastCopy(ctx context.Context, fsrc, fdst fs.Fs, files bilib.Names, queueName string) ([]Results, error) {
if b.InGracefulShutdown {
return nil, nil
}
ctx = b.preCopy(ctx)
if err := b.saveQueue(files, queueName); err != nil {
return nil, err
@ -220,6 +238,9 @@ func (b *bisyncRun) fastCopy(ctx context.Context, fsrc, fdst fs.Fs, files bilib.
}
}
b.SyncCI = fs.GetConfig(ctxCopy) // allows us to request graceful shutdown
accounting.MaxCompletedTransfers = -1 // we need a complete list in the event of graceful shutdown
ctxCopy, b.CancelSync = context.WithCancel(ctxCopy)
b.testFn()
err := sync.Sync(ctxCopy, fdst, fsrc, b.opt.CreateEmptySrcDirs)
prettyprint(logger, "logger", fs.LogLevelDebug)
@ -236,7 +257,7 @@ func (b *bisyncRun) fastCopy(ctx context.Context, fsrc, fdst fs.Fs, files bilib.
}
func (b *bisyncRun) retryFastCopy(ctx context.Context, fsrc, fdst fs.Fs, files bilib.Names, queueName string, results []Results, err error) ([]Results, error) {
if err != nil && b.opt.Resilient && b.opt.Retries > 1 {
if err != nil && b.opt.Resilient && !b.InGracefulShutdown && b.opt.Retries > 1 {
for tries := 1; tries <= b.opt.Retries; tries++ {
fs.Logf(queueName, Color(terminal.YellowFg, "Received error: %v - retrying as --resilient is set. Retry %d/%d"), err, tries, b.opt.Retries)
results, err = b.fastCopy(ctx, fsrc, fdst, files, queueName)
@ -259,6 +280,10 @@ func (b *bisyncRun) resyncDir(ctx context.Context, fsrc, fdst fs.Fs) ([]Results,
// operation should be "make" or "remove"
func (b *bisyncRun) syncEmptyDirs(ctx context.Context, dst fs.Fs, candidates bilib.Names, dirsList *fileList, results *[]Results, operation string) {
if b.InGracefulShutdown {
return
}
fs.Debugf(nil, "syncing empty dirs")
if b.opt.CreateEmptySrcDirs && (!b.opt.Resync || operation == "make") {
candidatesList := candidates.ToList()
@ -272,10 +297,11 @@ func (b *bisyncRun) syncEmptyDirs(ctx context.Context, dst fs.Fs, candidates bil
if dirsList.has(s) { //make sure it's a dir, not a file
r := Results{}
r.Name = s
r.Size = 0
r.Size = -1
r.Modtime = dirsList.getTime(s).In(time.UTC)
r.Flags = "d"
r.Err = nil
r.Origin = "syncEmptyDirs"
r.Winner = operations.Winner{ // note: Obj not set
Side: "src",
Err: nil,

View File

@ -507,6 +507,40 @@ Certain more serious errors will still enforce a `--resync` lockout, even in `--
Behavior of `--resilient` may change in a future version.
### --recover
If `--recover` is set, in the event of a sudden interruption or other
un-graceful shutdown, bisync will attempt to automatically recover on the next
run, instead of requiring `--resync`. Bisync is able to recover robustly by
keeping one "backup" listing at all times, representing the state of both paths
after the last known successful sync. Bisync can then compare the current state
with this snapshot to determine which changes it needs to retry. Changes that
were synced after this snapshot (during the run that was later interrupted)
will appear to bisync as if they are "new or changed on both sides", but in
most cases this is not a problem, as bisync will simply do its usual "equality
check" and learn that no action needs to be taken on these files, since they
are already identical on both sides.
In the rare event that a file is synced successfully during a run that later
aborts, and then that same file changes AGAIN before the next run, bisync will
think it is a sync conflict, and handle it accordingly. (From bisync's
perspective, the file has changed on both sides since the last trusted sync,
and the files on either side are not currently identical.) Therefore,
`--recover` carries with it a slightly increased chance of having conflicts --
though in practice this is pretty rare, as the conditions required to cause it
are quite specific. This risk can be reduced by using bisync's ["Graceful
Shutdown"](#graceful-shutdown) mode (triggered by sending `SIGINT` or
`Ctrl+C`), when you have the choice, instead of forcing a sudden termination.
`--recover` and `--resilient` are similar, but distinct -- the main difference
is that `--resilient` is about _retrying_, while `--recover` is about
_recovering_. Most users will probably want both. `--resilient` allows retrying
when bisync has chosen to abort itself due to safety features such as failing
`--check-access` or detecting a filter change. `--resilient` does not cover
external interruptions such as a user shutting down their computer in the
middle of a sync -- that is what `--recover` is for.
### --backup-dir1 and --backup-dir2
As of `v1.66`, [`--backup-dir`](/docs/#backup-dir-dir) is supported in bisync.
@ -670,6 +704,31 @@ lest there be replicated files, deleted files and general mayhem.
- `1` for a non-critical failing run (a rerun may be successful),
- `2` for a critically aborted run (requires a `--resync` to recover).
### Graceful Shutdown
Bisync has a "Graceful Shutdown" mode which is activated by sending `SIGINT` or
pressing `Ctrl+C` during a run. Once triggered, bisync will use best efforts to
exit cleanly before the timer runs out. If bisync is in the middle of
transferring files, it will attempt to cleanly empty its queue by finishing
what it has started but not taking more. If it cannot do so within 30 seconds,
it will cancel the in-progress transfers at that point and then give itself a
maximum of 60 seconds to wrap up, save its state for next time, and exit. With
the `-vP` flags you will see constant status updates and a final confirmation
of whether or not the graceful shutdown was successful.
At any point during the "Graceful Shutdown" sequence, a second `SIGINT` or
`Ctrl+C` will trigger an immediate, un-graceful exit, which will leave things
in a messier state. Usually a robust recovery will still be possible if using
[`--recover`](#recover) mode, otherwise you will need to do a `--resync`.
If you plan to use Graceful Shutdown mode, it is recommended to use
[`--resilient`](#resilient) and [`--recover`](#recover), and it is important to
NOT use [`--inplace`](/docs/#inplace), otherwise you risk leaving
partially-written files on one side, which may be confused for real files on
the next run. Note also that in the event of an abrupt interruption, a [lock
file](#lock-file) will be left behind to block concurrent runs. You will need
to delete it before you can proceed with the next run.
## Limitations
### Supported backends
@ -1498,6 +1557,8 @@ for performance improvements and less [risk of error](https://forum.rclone.org/t
instead of of `--size-only`, when `check` is not available.
* Bisync no longer fails to find the correct listing file when configs are overridden with backend-specific flags.
* Bisync now fully supports comparing based on any combination of size, modtime, and checksum, lifting the prior restriction on backends without modtime support.
* Bisync now supports a "Graceful Shutdown" mode to cleanly cancel a run early without requiring `--resync`.
* New `--recover` flag allows robust recovery in the event of interruptions, without requiring `--resync`.
### `v1.64`
* Fixed an [issue](https://forum.rclone.org/t/bisync-bugs-and-feature-requests/37636#:~:text=1.%20Dry%20runs%20are%20not%20completely%20dry)