sdk/go/keepclient/support.go

   1 // Copyright (C) The Arvados Authors. All rights reserved.
   2 //
   3 // SPDX-License-Identifier: Apache-2.0
   4
   5 package keepclient
   6
   7 import (
   8         "crypto/md5"
   9         "errors"
  10         "fmt"
  11         "io"
  12         "io/ioutil"
  13         "log"
  14         "net/http"
  15         "os"
  16         "strings"
  17
  18         "git.arvados.org/arvados.git/sdk/go/arvadosclient"
  19 )
  20
  21 // Function used to emit debug messages. The easiest way to enable
  22 // keepclient debug messages in your application is to assign
  23 // log.Printf to DebugPrintf.
  24 var DebugPrintf = func(string, ...interface{}) {}
  25
  26 func init() {
  27         if arvadosclient.StringBool(os.Getenv("ARVADOS_DEBUG")) {
  28                 DebugPrintf = log.Printf
  29         }
  30 }
  31
  32 type keepService struct {
  33         Uuid     string `json:"uuid"`
  34         Hostname string `json:"service_host"`
  35         Port     int    `json:"service_port"`
  36         SSL      bool   `json:"service_ssl_flag"`
  37         SvcType  string `json:"service_type"`
  38         ReadOnly bool   `json:"read_only"`
  39 }
  40
  41 // Md5String returns md5 hash for the bytes in the given string
  42 func Md5String(s string) string {
  43         return fmt.Sprintf("%x", md5.Sum([]byte(s)))
  44 }
  45
  46 type svcList struct {
  47         Items []keepService `json:"items"`
  48 }
  49
  50 type uploadStatus struct {
  51         err             error
  52         url             string
  53         statusCode      int
  54         replicas_stored int
  55         response        string
  56 }
  57
  58 func (this *KeepClient) uploadToKeepServer(host string, hash string, body io.Reader,
  59         upload_status chan<- uploadStatus, expectedLength int64, reqid string) {
  60
  61         var req *http.Request
  62         var err error
  63         var url = fmt.Sprintf("%s/%s", host, hash)
  64         if req, err = http.NewRequest("PUT", url, nil); err != nil {
  65                 DebugPrintf("DEBUG: [%s] Error creating request PUT %v error: %v", reqid, url, err.Error())
  66                 upload_status <- uploadStatus{err, url, 0, 0, ""}
  67                 return
  68         }
  69
  70         req.ContentLength = expectedLength
  71         if expectedLength > 0 {
  72                 req.Body = ioutil.NopCloser(body)
  73         } else {
  74                 // "For client requests, a value of 0 means unknown if
  75                 // Body is not nil."  In this case we do want the body
  76                 // to be empty, so don't set req.Body.
  77         }
  78
  79         req.Header.Add("X-Request-Id", reqid)
  80         req.Header.Add("Authorization", "OAuth2 "+this.Arvados.ApiToken)
  81         req.Header.Add("Content-Type", "application/octet-stream")
  82         req.Header.Add(X_Keep_Desired_Replicas, fmt.Sprint(this.Want_replicas))
  83         if len(this.StorageClasses) > 0 {
  84                 req.Header.Add("X-Keep-Storage-Classes", strings.Join(this.StorageClasses, ", "))
  85         }
  86
  87         var resp *http.Response
  88         if resp, err = this.httpClient().Do(req); err != nil {
  89                 DebugPrintf("DEBUG: [%s] Upload failed %v error: %v", reqid, url, err.Error())
  90                 upload_status <- uploadStatus{err, url, 0, 0, err.Error()}
  91                 return
  92         }
  93
  94         rep := 1
  95         if xr := resp.Header.Get(X_Keep_Replicas_Stored); xr != "" {
  96                 fmt.Sscanf(xr, "%d", &rep)
  97         }
  98
  99         defer resp.Body.Close()
 100         defer io.Copy(ioutil.Discard, resp.Body)
 101
 102         respbody, err2 := ioutil.ReadAll(&io.LimitedReader{R: resp.Body, N: 4096})
 103         response := strings.TrimSpace(string(respbody))
 104         if err2 != nil && err2 != io.EOF {
 105                 DebugPrintf("DEBUG: [%s] Upload %v error: %v response: %v", reqid, url, err2.Error(), response)
 106                 upload_status <- uploadStatus{err2, url, resp.StatusCode, rep, response}
 107         } else if resp.StatusCode == http.StatusOK {
 108                 DebugPrintf("DEBUG: [%s] Upload %v success", reqid, url)
 109                 upload_status <- uploadStatus{nil, url, resp.StatusCode, rep, response}
 110         } else {
 111                 if resp.StatusCode >= 300 && response == "" {
 112                         response = resp.Status
 113                 }
 114                 DebugPrintf("DEBUG: [%s] Upload %v error: %v response: %v", reqid, url, resp.StatusCode, response)
 115                 upload_status <- uploadStatus{errors.New(resp.Status), url, resp.StatusCode, rep, response}
 116         }
 117 }
 118
 119 func (this *KeepClient) putReplicas(
 120         hash string,
 121         getReader func() io.Reader,
 122         expectedLength int64) (locator string, replicas int, err error) {
 123
 124         reqid := this.getRequestID()
 125
 126         // Calculate the ordering for uploading to servers
 127         sv := NewRootSorter(this.WritableLocalRoots(), hash).GetSortedRoots()
 128
 129         // The next server to try contacting
 130         nextServer := 0
 131
 132         // The number of active writers
 133         active := 0
 134
 135         // Used to communicate status from the upload goroutines
 136         upload_status := make(chan uploadStatus)
 137         defer func() {
 138                 // Wait for any abandoned uploads (e.g., we started
 139                 // two uploads and the first replied with replicas=2)
 140                 // to finish before closing the status channel.
 141                 go func() {
 142                         for active > 0 {
 143                                 <-upload_status
 144                         }
 145                         close(upload_status)
 146                 }()
 147         }()
 148
 149         replicasDone := 0
 150         replicasTodo := this.Want_replicas
 151
 152         replicasPerThread := this.replicasPerService
 153         if replicasPerThread < 1 {
 154                 // unlimited or unknown
 155                 replicasPerThread = replicasTodo
 156         }
 157
 158         retriesRemaining := 1 + this.Retries
 159         var retryServers []string
 160
 161         lastError := make(map[string]string)
 162
 163         for retriesRemaining > 0 {
 164                 retriesRemaining -= 1
 165                 nextServer = 0
 166                 retryServers = []string{}
 167                 for replicasTodo > 0 {
 168                         for active*replicasPerThread < replicasTodo {
 169                                 // Start some upload requests
 170                                 if nextServer < len(sv) {
 171                                         DebugPrintf("DEBUG: [%s] Begin upload %s to %s", reqid, hash, sv[nextServer])
 172                                         go this.uploadToKeepServer(sv[nextServer], hash, getReader(), upload_status, expectedLength, reqid)
 173                                         nextServer += 1
 174                                         active += 1
 175                                 } else {
 176                                         if active == 0 && retriesRemaining == 0 {
 177                                                 msg := "Could not write sufficient replicas: "
 178                                                 for _, resp := range lastError {
 179                                                         msg += resp + "; "
 180                                                 }
 181                                                 msg = msg[:len(msg)-2]
 182                                                 return locator, replicasDone, InsufficientReplicasError(errors.New(msg))
 183                                         }
 184                                         break
 185                                 }
 186                         }
 187                         DebugPrintf("DEBUG: [%s] Replicas remaining to write: %v active uploads: %v",
 188                                 reqid, replicasTodo, active)
 189
 190                         // Now wait for something to happen.
 191                         if active > 0 {
 192                                 status := <-upload_status
 193                                 active -= 1
 194
 195                                 if status.statusCode == 200 {
 196                                         // good news!
 197                                         replicasDone += status.replicas_stored
 198                                         replicasTodo -= status.replicas_stored
 199                                         locator = status.response
 200                                         delete(lastError, status.url)
 201                                 } else {
 202                                         msg := fmt.Sprintf("[%d] %s", status.statusCode, status.response)
 203                                         if len(msg) > 100 {
 204                                                 msg = msg[:100]
 205                                         }
 206                                         lastError[status.url] = msg
 207                                 }
 208
 209                                 if status.statusCode == 0 || status.statusCode == 408 || status.statusCode == 429 ||
 210                                         (status.statusCode >= 500 && status.statusCode != 503) {
 211                                         // Timeout, too many requests, or other server side failure
 212                                         // Do not retry when status code is 503, which means the keep server is full
 213                                         retryServers = append(retryServers, status.url[0:strings.LastIndex(status.url, "/")])
 214                                 }
 215                         } else {
 216                                 break
 217                         }
 218                 }
 219
 220                 sv = retryServers
 221         }
 222
 223         return locator, replicasDone, nil
 224 }