X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/d81ed360051af98d7c0fba3afb07a4b5a815ee41..f69d2824c997c53caa11d30ba816768bad52e12b:/services/keepstore/handlers.go diff --git a/services/keepstore/handlers.go b/services/keepstore/handlers.go index f120f05dc4..9e178fbfdb 100644 --- a/services/keepstore/handlers.go +++ b/services/keepstore/handlers.go @@ -8,7 +8,6 @@ package main // StatusHandler (GET /status.json) import ( - "bufio" "bytes" "container/list" "crypto/md5" @@ -83,38 +82,6 @@ func BadRequestHandler(w http.ResponseWriter, r *http.Request) { http.Error(w, BadRequestError.Error(), BadRequestError.HTTPCode) } -// FindKeepVolumes scans all mounted volumes on the system for Keep -// volumes, and returns a list of matching paths. -// -// A device is assumed to be a Keep volume if it is a normal or tmpfs -// volume and has a "/keep" directory directly underneath the mount -// point. -// -func FindKeepVolumes() []string { - vols := make([]string, 0) - - if f, err := os.Open(PROC_MOUNTS); err != nil { - log.Fatalf("opening %s: %s\n", PROC_MOUNTS, err) - } else { - scanner := bufio.NewScanner(f) - for scanner.Scan() { - args := strings.Fields(scanner.Text()) - dev, mount := args[0], args[1] - if mount != "/" && - (dev == "tmpfs" || strings.HasPrefix(dev, "/dev/")) { - keep := mount + "/keep" - if st, err := os.Stat(keep); err == nil && st.IsDir() { - vols = append(vols, keep) - } - } - } - if err := scanner.Err(); err != nil { - log.Fatal(err) - } - } - return vols -} - func GetBlockHandler(resp http.ResponseWriter, req *http.Request) { hash := mux.Vars(req)["hash"] @@ -235,7 +202,7 @@ func IndexHandler(resp http.ResponseWriter, req *http.Request) { prefix := mux.Vars(req)["prefix"] var index string - for _, vol := range KeepVM.Volumes() { + for _, vol := range KeepVM.AllReadable() { index = index + vol.Index(prefix) } resp.Write([]byte(index)) @@ -282,8 +249,8 @@ func StatusHandler(resp http.ResponseWriter, req *http.Request) { func GetNodeStatus() *NodeStatus { st := new(NodeStatus) - st.Volumes = make([]*VolumeStatus, len(KeepVM.Volumes())) - for i, vol := range KeepVM.Volumes() { + st.Volumes = make([]*VolumeStatus, len(KeepVM.AllReadable())) + for i, vol := range KeepVM.AllReadable() { st.Volumes[i] = vol.Status() } return st @@ -358,14 +325,14 @@ func DeleteHandler(resp http.ResponseWriter, req *http.Request) { return } - // Delete copies of this block from all available volumes. Report - // how many blocks were successfully and unsuccessfully - // deleted. + // Delete copies of this block from all available volumes. + // Report how many blocks were successfully deleted, and how + // many were found on writable volumes but not deleted. var result struct { Deleted int `json:"copies_deleted"` Failed int `json:"copies_failed"` } - for _, vol := range KeepVM.Volumes() { + for _, vol := range KeepVM.AllWritable() { if err := vol.Delete(hash); err == nil { result.Deleted++ } else if os.IsNotExist(err) { @@ -528,52 +495,54 @@ func GetBlock(hash string, update_timestamp bool) ([]byte, error) { // Attempt to read the requested hash from a keep volume. error_to_caller := NotFoundError - for _, vol := range KeepVM.Volumes() { - if buf, err := vol.Get(hash); err != nil { - // IsNotExist is an expected error and may be ignored. - // (If all volumes report IsNotExist, we return a NotFoundError) - // All other errors should be logged but we continue trying to - // read. - switch { - case os.IsNotExist(err): - continue - default: + var vols []Volume + if update_timestamp { + // Pointless to find the block on an unwritable volume + // because Touch() will fail -- this is as good as + // "not found" for purposes of callers who need to + // update_timestamp. + vols = KeepVM.AllWritable() + } else { + vols = KeepVM.AllReadable() + } + + for _, vol := range vols { + buf, err := vol.Get(hash) + if err != nil { + // IsNotExist is an expected error and may be + // ignored. All other errors are logged. In + // any case we continue trying to read other + // volumes. If all volumes report IsNotExist, + // we return a NotFoundError. + if !os.IsNotExist(err) { log.Printf("GetBlock: reading %s: %s\n", hash, err) } - } else { - // Double check the file checksum. - // - filehash := fmt.Sprintf("%x", md5.Sum(buf)) - if filehash != hash { - // TODO(twp): this condition probably represents a bad disk and - // should raise major alarm bells for an administrator: e.g. - // they should be sent directly to an event manager at high - // priority or logged as urgent problems. - // - log.Printf("%s: checksum mismatch for request %s (actual %s)\n", - vol, hash, filehash) - error_to_caller = DiskHashError - } else { - // Success! - if error_to_caller != NotFoundError { - log.Printf("%s: checksum mismatch for request %s but a good copy was found on another volume and returned\n", - vol, hash) - } - // Update the timestamp if the caller requested. - // If we could not update the timestamp, continue looking on - // other volumes. - if update_timestamp { - if vol.Touch(hash) != nil { - continue - } - } - return buf, nil + continue + } + // Check the file checksum. + // + filehash := fmt.Sprintf("%x", md5.Sum(buf)) + if filehash != hash { + // TODO: Try harder to tell a sysadmin about + // this. + log.Printf("%s: checksum mismatch for request %s (actual %s)\n", + vol, hash, filehash) + error_to_caller = DiskHashError + continue + } + if error_to_caller == DiskHashError { + log.Printf("%s: checksum mismatch for request %s but a good copy was found on another volume and returned", + vol, hash) + } + if update_timestamp { + if err := vol.Touch(hash); err != nil { + error_to_caller = GenericError + log.Printf("%s: Touch %s failed: %s", + vol, hash, error_to_caller) + continue } } - } - - if error_to_caller != NotFoundError { - log.Printf("%s: checksum mismatch, no good copy found\n", hash) + return buf, nil } return nil, error_to_caller } @@ -630,31 +599,39 @@ func PutBlock(block []byte, hash string) error { // Choose a Keep volume to write to. // If this volume fails, try all of the volumes in order. - vol := KeepVM.Choose() - if err := vol.Put(hash, block); err == nil { - return nil // success! - } else { - allFull := true - for _, vol := range KeepVM.Volumes() { - err := vol.Put(hash, block) - if err == nil { - return nil // success! - } - if err != FullError { - // The volume is not full but the write did not succeed. - // Report the error and continue trying. - allFull = false - log.Printf("%s: Write(%s): %s\n", vol, hash, err) - } + if vol := KeepVM.NextWritable(); vol != nil { + if err := vol.Put(hash, block); err == nil { + return nil // success! } + } - if allFull { - log.Printf("all Keep volumes full") - return FullError - } else { - log.Printf("all Keep volumes failed") - return GenericError + writables := KeepVM.AllWritable() + if len(writables) == 0 { + log.Print("No writable volumes.") + return FullError + } + + allFull := true + for _, vol := range writables { + err := vol.Put(hash, block) + if err == nil { + return nil // success! } + if err != FullError { + // The volume is not full but the + // write did not succeed. Report the + // error and continue trying. + allFull = false + log.Printf("%s: Write(%s): %s\n", vol, hash, err) + } + } + + if allFull { + log.Print("All volumes are full.") + return FullError + } else { + // Already logged the non-full errors. + return GenericError } }