X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/b2bcd45082d2df2b5a17645eb60473cc17c76e88..8db0d3197f659a4099e481b464cb9a877b943d3c:/services/keepstore/azure_blob_volume.go diff --git a/services/keepstore/azure_blob_volume.go b/services/keepstore/azure_blob_volume.go index 35b1dc79bf..48cb02647c 100644 --- a/services/keepstore/azure_blob_volume.go +++ b/services/keepstore/azure_blob_volume.go @@ -1,6 +1,7 @@ package main import ( + "bytes" "errors" "flag" "fmt" @@ -8,15 +9,22 @@ import ( "io/ioutil" "log" "os" + "regexp" + "strconv" "strings" + "sync" "time" - "github.com/Azure/azure-sdk-for-go/storage" + "github.com/curoverse/azure-sdk-for-go/storage" ) var ( + azureMaxGetBytes int azureStorageAccountName string azureStorageAccountKeyFile string + azureStorageReplication int + azureWriteRaceInterval = 15 * time.Second + azureWriteRacePollTime = time.Second ) func readKeyFromFile(file string) (string, error) { @@ -36,9 +44,16 @@ type azureVolumeAdder struct { } func (s *azureVolumeAdder) Set(containerName string) error { + if trashLifetime != 0 { + return ErrNotImplemented + } + if containerName == "" { return errors.New("no container name given") } + if azureStorageAccountName == "" || azureStorageAccountKeyFile == "" { + return errors.New("-azure-storage-account-name and -azure-storage-account-key-file arguments must given before -azure-storage-container-volume") + } accountKey, err := readKeyFromFile(azureStorageAccountKeyFile) if err != nil { return err @@ -50,7 +65,7 @@ func (s *azureVolumeAdder) Set(containerName string) error { if flagSerializeIO { log.Print("Notice: -serialize is not supported by azure-blob-container volumes.") } - v := NewAzureBlobVolume(azClient, containerName, flagReadonly) + v := NewAzureBlobVolume(azClient, containerName, flagReadonly, azureStorageReplication) if err := v.Check(); err != nil { return err } @@ -72,6 +87,16 @@ func init() { "azure-storage-account-key-file", "", "File containing the account key used for subsequent --azure-storage-container-volume arguments.") + flag.IntVar( + &azureStorageReplication, + "azure-storage-replication", + 3, + "Replication level to report to clients when data is stored in an Azure container.") + flag.IntVar( + &azureMaxGetBytes, + "azure-max-get-bytes", + BlockSize, + fmt.Sprintf("Maximum bytes to request in a single GET request. If smaller than %d, use multiple concurrent range requests to retrieve a block.", BlockSize)) } // An AzureBlobVolume stores and retrieves blocks in an Azure Blob @@ -81,14 +106,19 @@ type AzureBlobVolume struct { bsClient storage.BlobStorageClient containerName string readonly bool + replication int } -func NewAzureBlobVolume(client storage.Client, containerName string, readonly bool) *AzureBlobVolume { +// NewAzureBlobVolume returns a new AzureBlobVolume using the given +// client and container name. The replication argument specifies the +// replication level to report when writing data. +func NewAzureBlobVolume(client storage.Client, containerName string, readonly bool, replication int) *AzureBlobVolume { return &AzureBlobVolume{ - azClient: client, - bsClient: client.GetBlobService(), + azClient: client, + bsClient: client.GetBlobService(), containerName: containerName, - readonly: readonly, + readonly: readonly, + replication: replication, } } @@ -104,69 +134,183 @@ func (v *AzureBlobVolume) Check() error { return nil } -func (v *AzureBlobVolume) Get(loc string) ([]byte, error) { - rdr, err := v.bsClient.GetBlob(v.containerName, loc) +// Return true if expires_at metadata attribute is found on the block +func (v *AzureBlobVolume) checkTrashed(loc string) (bool, map[string]string, error) { + metadata, err := v.bsClient.GetBlobMetadata(v.containerName, loc) + if err != nil { + return false, metadata, v.translateError(err) + } + if metadata["expires_at"] != "" { + return true, metadata, nil + } + return false, metadata, nil +} + +// Get reads a Keep block that has been stored as a block blob in the +// container. +// +// If the block is younger than azureWriteRaceInterval and is +// unexpectedly empty, assume a PutBlob operation is in progress, and +// wait for it to finish writing. +func (v *AzureBlobVolume) Get(loc string, buf []byte) (int, error) { + trashed, _, err := v.checkTrashed(loc) if err != nil { - if strings.Contains(err.Error(), "404 Not Found") { - // "storage: service returned without a response body (404 Not Found)" - return nil, os.ErrNotExist + return 0, err + } + if trashed { + return 0, os.ErrNotExist + } + var deadline time.Time + haveDeadline := false + size, err := v.get(loc, buf) + for err == nil && size == 0 && loc != "d41d8cd98f00b204e9800998ecf8427e" { + // Seeing a brand new empty block probably means we're + // in a race with CreateBlob, which under the hood + // (apparently) does "CreateEmpty" and "CommitData" + // with no additional transaction locking. + if !haveDeadline { + t, err := v.Mtime(loc) + if err != nil { + log.Print("Got empty block (possible race) but Mtime failed: ", err) + break + } + deadline = t.Add(azureWriteRaceInterval) + if time.Now().After(deadline) { + break + } + log.Printf("Race? Block %s is 0 bytes, %s old. Polling until %s", loc, time.Since(t), deadline) + haveDeadline = true + } else if time.Now().After(deadline) { + break } - return nil, err + time.Sleep(azureWriteRacePollTime) + size, err = v.get(loc, buf) } - switch err := err.(type) { - case nil: - default: - log.Printf("ERROR IN Get(): %T %#v", err, err) - return nil, err + if haveDeadline { + log.Printf("Race ended with size==%d", size) } - defer rdr.Close() - buf := bufs.Get(BlockSize) - n, err := io.ReadFull(rdr, buf) - switch err { - case io.EOF, io.ErrUnexpectedEOF: - return buf[:n], nil - default: - bufs.Put(buf) - return nil, err + return size, err +} + +func (v *AzureBlobVolume) get(loc string, buf []byte) (int, error) { + expectSize := len(buf) + if azureMaxGetBytes < BlockSize { + // Unfortunately the handler doesn't tell us how long the blob + // is expected to be, so we have to ask Azure. + props, err := v.bsClient.GetBlobProperties(v.containerName, loc) + if err != nil { + return 0, v.translateError(err) + } + if props.ContentLength > int64(BlockSize) || props.ContentLength < 0 { + return 0, fmt.Errorf("block %s invalid size %d (max %d)", loc, props.ContentLength, BlockSize) + } + expectSize = int(props.ContentLength) + } + + if expectSize == 0 { + return 0, nil } + + // We'll update this actualSize if/when we get the last piece. + actualSize := -1 + pieces := (expectSize + azureMaxGetBytes - 1) / azureMaxGetBytes + errors := make([]error, pieces) + var wg sync.WaitGroup + wg.Add(pieces) + for p := 0; p < pieces; p++ { + go func(p int) { + defer wg.Done() + startPos := p * azureMaxGetBytes + endPos := startPos + azureMaxGetBytes + if endPos > expectSize { + endPos = expectSize + } + var rdr io.ReadCloser + var err error + if startPos == 0 && endPos == expectSize { + rdr, err = v.bsClient.GetBlob(v.containerName, loc) + } else { + rdr, err = v.bsClient.GetBlobRange(v.containerName, loc, fmt.Sprintf("%d-%d", startPos, endPos-1), nil) + } + if err != nil { + errors[p] = err + return + } + defer rdr.Close() + n, err := io.ReadFull(rdr, buf[startPos:endPos]) + if pieces == 1 && (err == io.ErrUnexpectedEOF || err == io.EOF) { + // If we don't know the actual size, + // and just tried reading 64 MiB, it's + // normal to encounter EOF. + } else if err != nil { + errors[p] = err + } + if p == pieces-1 { + actualSize = startPos + n + } + }(p) + } + wg.Wait() + for _, err := range errors { + if err != nil { + return 0, v.translateError(err) + } + } + return actualSize, nil } +// Compare the given data with existing stored data. func (v *AzureBlobVolume) Compare(loc string, expect []byte) error { - rdr, err := v.bsClient.GetBlob(v.containerName, loc) + trashed, _, err := v.checkTrashed(loc) if err != nil { return err } + if trashed { + return os.ErrNotExist + } + rdr, err := v.bsClient.GetBlob(v.containerName, loc) + if err != nil { + return v.translateError(err) + } defer rdr.Close() return compareReaderWithBuf(rdr, expect, loc[:32]) } +// Put stores a Keep block as a block blob in the container. func (v *AzureBlobVolume) Put(loc string, block []byte) error { if v.readonly { return MethodDisabledError } - if err := v.bsClient.CreateBlockBlob(v.containerName, loc); err != nil { - return err - } - // We use the same block ID, base64("0")=="MA==", for everything. - if err := v.bsClient.PutBlock(v.containerName, loc, "MA==", block); err != nil { - return err - } - return v.bsClient.PutBlockList(v.containerName, loc, []storage.Block{{"MA==", storage.BlockStatusUncommitted}}) + return v.bsClient.CreateBlockBlobFromReader(v.containerName, loc, uint64(len(block)), bytes.NewReader(block), nil) } +// Touch updates the last-modified property of a block blob. func (v *AzureBlobVolume) Touch(loc string) error { if v.readonly { return MethodDisabledError } - if exists, err := v.bsClient.BlobExists(v.containerName, loc); err != nil { + trashed, metadata, err := v.checkTrashed(loc) + if err != nil { return err - } else if !exists { + } + if trashed { return os.ErrNotExist } - return v.bsClient.PutBlockList(v.containerName, loc, []storage.Block{{"MA==", storage.BlockStatusCommitted}}) + + metadata["touch"] = fmt.Sprintf("%d", time.Now()) + return v.bsClient.SetBlobMetadata(v.containerName, loc, metadata, nil) } +// Mtime returns the last-modified property of a block blob. func (v *AzureBlobVolume) Mtime(loc string) (time.Time, error) { + trashed, _, err := v.checkTrashed(loc) + if err != nil { + return time.Time{}, err + } + if trashed { + return time.Time{}, os.ErrNotExist + } + props, err := v.bsClient.GetBlobProperties(v.containerName, loc) if err != nil { return time.Time{}, err @@ -174,9 +318,12 @@ func (v *AzureBlobVolume) Mtime(loc string) (time.Time, error) { return time.Parse(time.RFC1123, props.LastModified) } +// IndexTo writes a list of Keep blocks that are stored in the +// container. func (v *AzureBlobVolume) IndexTo(prefix string, writer io.Writer) error { params := storage.ListBlobsParameters{ - Prefix: prefix, + Prefix: prefix, + Include: "metadata", } for { resp, err := v.bsClient.ListBlobs(v.containerName, params) @@ -188,7 +335,22 @@ func (v *AzureBlobVolume) IndexTo(prefix string, writer io.Writer) error { if err != nil { return err } - fmt.Fprintf(writer, "%s+%d %d\n", b.Name, b.Properties.ContentLength, t.Unix()) + if !v.isKeepBlock(b.Name) { + continue + } + if b.Properties.ContentLength == 0 && t.Add(azureWriteRaceInterval).After(time.Now()) { + // A new zero-length blob is probably + // just a new non-empty blob that + // hasn't committed its data yet (see + // Get()), and in any case has no + // value. + continue + } + if b.Metadata["expires_at"] != "" { + // Trashed blob; exclude it from response + continue + } + fmt.Fprintf(writer, "%s+%d %d\n", b.Name, b.Properties.ContentLength, t.UnixNano()) } if resp.NextMarker == "" { return nil @@ -197,19 +359,61 @@ func (v *AzureBlobVolume) IndexTo(prefix string, writer io.Writer) error { } } -func (v *AzureBlobVolume) Delete(loc string) error { - // TODO: Use leases to handle races with Touch and Put. +// Trash a Keep block. +func (v *AzureBlobVolume) Trash(loc string) error { if v.readonly { return MethodDisabledError } + + // Ideally we would use If-Unmodified-Since, but that + // particular condition seems to be ignored by Azure. Instead, + // we get the Etag before checking Mtime, and use If-Match to + // ensure we don't delete data if Put() or Touch() happens + // between our calls to Mtime() and DeleteBlob(). + props, err := v.bsClient.GetBlobProperties(v.containerName, loc) + if err != nil { + return err + } if t, err := v.Mtime(loc); err != nil { return err } else if time.Since(t) < blobSignatureTTL { return nil } - return v.bsClient.DeleteBlob(v.containerName, loc) + + // If trashLifetime == 0, just delete it + if trashLifetime == 0 { + return v.bsClient.DeleteBlob(v.containerName, loc, map[string]string{ + "If-Match": props.Etag, + }) + } + + // Otherwise, mark as trash + return v.bsClient.SetBlobMetadata(v.containerName, loc, map[string]string{ + "expires_at": fmt.Sprintf("%d", time.Now().Add(trashLifetime).Unix()), + }, map[string]string{ + "If-Match": props.Etag, + }) } +// Untrash a Keep block. +// Delete the expires_at metadata attribute +func (v *AzureBlobVolume) Untrash(loc string) error { + // if expires_at does not exist, return NotFoundError + metadata, err := v.bsClient.GetBlobMetadata(v.containerName, loc) + if err != nil { + return v.translateError(err) + } + if metadata["expires_at"] == "" { + return os.ErrNotExist + } + + // reset expires_at metadata attribute + metadata["expires_at"] = "" + err = v.bsClient.SetBlobMetadata(v.containerName, loc, metadata, nil) + return v.translateError(err) +} + +// Status returns a VolumeStatus struct with placeholder data. func (v *AzureBlobVolume) Status() *VolumeStatus { return &VolumeStatus{ DeviceNum: 1, @@ -218,10 +422,90 @@ func (v *AzureBlobVolume) Status() *VolumeStatus { } } +// String returns a volume label, including the container name. func (v *AzureBlobVolume) String() string { return fmt.Sprintf("azure-storage-container:%+q", v.containerName) } +// Writable returns true, unless the -readonly flag was on when the +// volume was added. func (v *AzureBlobVolume) Writable() bool { return !v.readonly } + +// Replication returns the replication level of the container, as +// specified by the -azure-storage-replication argument. +func (v *AzureBlobVolume) Replication() int { + return v.replication +} + +// If possible, translate an Azure SDK error to a recognizable error +// like os.ErrNotExist. +func (v *AzureBlobVolume) translateError(err error) error { + switch { + case err == nil: + return err + case strings.Contains(err.Error(), "Not Found"): + // "storage: service returned without a response body (404 Not Found)" + return os.ErrNotExist + default: + return err + } +} + +var keepBlockRegexp = regexp.MustCompile(`^[0-9a-f]{32}$`) + +func (v *AzureBlobVolume) isKeepBlock(s string) bool { + return keepBlockRegexp.MatchString(s) +} + +// EmptyTrash looks for trashed blocks that exceeded trashLifetime +// and deletes them from the volume. +func (v *AzureBlobVolume) EmptyTrash() { + var bytesDeleted, bytesInTrash int64 + var blocksDeleted, blocksInTrash int + params := storage.ListBlobsParameters{Include: "metadata"} + + for { + resp, err := v.bsClient.ListBlobs(v.containerName, params) + if err != nil { + log.Printf("EmptyTrash: ListBlobs: %v", err) + break + } + for _, b := range resp.Blobs { + // Check if the block is expired + if b.Metadata["expires_at"] == "" { + continue + } + + blocksInTrash++ + bytesInTrash += b.Properties.ContentLength + + expiresAt, err := strconv.ParseInt(b.Metadata["expires_at"], 10, 64) + if err != nil { + log.Printf("EmptyTrash: ParseInt(%v): %v", b.Metadata["expires_at"], err) + continue + } + + if expiresAt > time.Now().Unix() { + continue + } + + err = v.bsClient.DeleteBlob(v.containerName, b.Name, map[string]string{ + "If-Match": b.Properties.Etag, + }) + if err != nil { + log.Printf("EmptyTrash: DeleteBlob(%v): %v", b.Name, err) + continue + } + blocksDeleted++ + bytesDeleted += b.Properties.ContentLength + } + if resp.NextMarker == "" { + break + } + params.Marker = resp.NextMarker + } + + log.Printf("EmptyTrash stats for %v: Deleted %v bytes in %v blocks. Remaining in trash: %v bytes in %v blocks.", v.String(), bytesDeleted, blocksDeleted, bytesInTrash-bytesDeleted, blocksInTrash-blocksDeleted) +}