import (
"bufio"
"bytes"
+ "container/list"
"crypto/md5"
"encoding/json"
"fmt"
`/index/{prefix:[0-9a-f]{0,32}}`, IndexHandler).Methods("GET", "HEAD")
rest.HandleFunc(`/status.json`, StatusHandler).Methods("GET", "HEAD")
+ // The PullHandler processes "PUT /pull" commands from Data Manager.
+ // It parses the JSON list of pull requests in the request body, and
+ // delivers them to the pull list manager for replication.
+ rest.HandleFunc(`/pull`, PullHandler).Methods("PUT")
+
// Any request which does not match any of these routes gets
// 400 Bad Request.
rest.NotFoundHandler = http.HandlerFunc(BadRequestHandler)
}
}
- block, err := GetBlock(hash)
+ block, err := GetBlock(hash, false)
// Garbage collect after each GET. Fixes #2865.
// TODO(twp): review Keep memory usage and see if there's
}
}
-func GetBlock(hash string) ([]byte, error) {
+/* PullHandler processes "PUT /pull" requests for the data manager.
+ The request body is a JSON message containing a list of pull
+ requests in the following format:
+
+ [
+ {
+ "locator":"e4d909c290d0fb1ca068ffaddf22cbd0+4985",
+ "servers":[
+ "keep0.qr1hi.arvadosapi.com:25107",
+ "keep1.qr1hi.arvadosapi.com:25108"
+ ]
+ },
+ {
+ "locator":"55ae4d45d2db0793d53f03e805f656e5+658395",
+ "servers":[
+ "10.0.1.5:25107",
+ "10.0.1.6:25107",
+ "10.0.1.7:25108"
+ ]
+ },
+ ...
+ ]
+
+ Each pull request in the list consists of a block locator string
+ and an ordered list of servers. Keepstore should try to fetch the
+ block from each server in turn.
+
+ If the request has not been sent by the Data Manager, return 401
+ Unauthorized.
+
+ If the JSON unmarshalling fails, return 400 Bad Request.
+*/
+
+type PullRequest struct {
+ Locator string `json:"locator"`
+ Servers []string `json:"servers"`
+}
+
+func PullHandler(resp http.ResponseWriter, req *http.Request) {
+ // Reject unauthorized requests.
+ api_token := GetApiToken(req)
+ if !IsDataManagerToken(api_token) {
+ http.Error(resp, UnauthorizedError.Error(), UnauthorizedError.HTTPCode)
+ log.Printf("%s %s: %s\n", req.Method, req.URL, UnauthorizedError.Error())
+ return
+ }
+
+ // Parse the request body.
+ var pr []PullRequest
+ r := json.NewDecoder(req.Body)
+ if err := r.Decode(&pr); err != nil {
+ http.Error(resp, BadRequestError.Error(), BadRequestError.HTTPCode)
+ log.Printf("%s %s: %s\n", req.Method, req.URL, err.Error())
+ return
+ }
+
+ // We have a properly formatted pull list sent from the data
+ // manager. Report success and send the list to the pull list
+ // manager for further handling.
+ log.Printf("%s %s: received %v\n", req.Method, req.URL, pr)
+ resp.WriteHeader(http.StatusOK)
+ resp.Write([]byte(
+ fmt.Sprintf("Received %d pull requests\n", len(pr))))
+
+ plist := list.New()
+ for _, p := range pr {
+ plist.PushBack(p)
+ }
+
+ if pullmgr == nil {
+ pullmgr = NewBlockWorkList()
+ }
+ pullmgr.ReplaceList(plist)
+}
+
+// ==============================
+// GetBlock and PutBlock implement lower-level code for handling
+// blocks by rooting through volumes connected to the local machine.
+// Once the handler has determined that system policy permits the
+// request, it calls these methods to perform the actual operation.
+//
+// TODO(twp): this code would probably be better located in the
+// VolumeManager interface. As an abstraction, the VolumeManager
+// should be the only part of the code that cares about which volume a
+// block is stored on, so it should be responsible for figuring out
+// which volume to check for fetching blocks, storing blocks, etc.
+
+// ==============================
+// GetBlock fetches and returns the block identified by "hash". If
+// the update_timestamp argument is true, GetBlock also updates the
+// block's file modification time (for the sake of PutBlock, which
+// must update the file's timestamp when the block already exists).
+//
+// On success, GetBlock returns a byte slice with the block data, and
+// a nil error.
+//
+// If the block cannot be found on any volume, returns NotFoundError.
+//
+// If the block found does not have the correct MD5 hash, returns
+// DiskHashError.
+//
+
+func GetBlock(hash string, update_timestamp bool) ([]byte, error) {
// Attempt to read the requested hash from a keep volume.
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
}
}
}
// If we already have a block on disk under this identifier, return
- // success (but check for MD5 collisions).
+ // success (but check for MD5 collisions). While fetching the block,
+ // update its timestamp.
// The only errors that GetBlock can return are DiskHashError and NotFoundError.
// In either case, we want to write our new (good) block to disk,
// so there is nothing special to do if err != nil.
- if oldblock, err := GetBlock(hash); err == nil {
+ //
+ if oldblock, err := GetBlock(hash, true); err == nil {
if bytes.Compare(block, oldblock) == 0 {
+ // The block already exists; return success.
return nil
} else {
return CollisionError
}
// Blocks may be deleted only when Keep has been configured with a
// data manager.
- if data_manager_token == "" {
- return false
- }
- if api_token == data_manager_token {
+ if IsDataManagerToken(api_token) {
return true
}
// TODO(twp): look up api_token with the API server
// has unlimited scope
return false
}
+
+// IsDataManagerToken returns true if api_token represents the data
+// manager's token.
+func IsDataManagerToken(api_token string) bool {
+ return data_manager_token != "" && api_token == data_manager_token
+}
projects / arvados.git / blobdiff