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         "math/rand"
  15         "net/http"
  16         "os"
  17         "strings"
  18
  19         "git.curoverse.com/arvados.git/sdk/go/arvadosclient"
  20 )
  21
  22 // Function used to emit debug messages. The easiest way to enable
  23 // keepclient debug messages in your application is to assign
  24 // log.Printf to DebugPrintf.
  25 var DebugPrintf = func(string, ...interface{}) {}
  26
  27 func init() {
  28         if arvadosclient.StringBool(os.Getenv("ARVADOS_DEBUG")) {
  29                 DebugPrintf = log.Printf
  30         }
  31 }
  32
  33 type keepService struct {
  34         Uuid     string `json:"uuid"`
  35         Hostname string `json:"service_host"`
  36         Port     int    `json:"service_port"`
  37         SSL      bool   `json:"service_ssl_flag"`
  38         SvcType  string `json:"service_type"`
  39         ReadOnly bool   `json:"read_only"`
  40 }
  41
  42 // Md5String returns md5 hash for the bytes in the given string
  43 func Md5String(s string) string {
  44         return fmt.Sprintf("%x", md5.Sum([]byte(s)))
  45 }
  46
  47 type svcList struct {
  48         Items []keepService `json:"items"`
  49 }
  50
  51 type uploadStatus struct {
  52         err             error
  53         url             string
  54         statusCode      int
  55         replicas_stored int
  56         response        string
  57 }
  58
  59 func (this *KeepClient) uploadToKeepServer(host string, hash string, body io.Reader,
  60         upload_status chan<- uploadStatus, expectedLength int64, requestID int32) {
  61
  62         var req *http.Request
  63         var err error
  64         var url = fmt.Sprintf("%s/%s", host, hash)
  65         if req, err = http.NewRequest("PUT", url, nil); err != nil {
  66                 DebugPrintf("DEBUG: [%08x] Error creating request PUT %v error: %v", requestID, url, err.Error())
  67                 upload_status <- uploadStatus{err, url, 0, 0, ""}
  68                 return
  69         }
  70
  71         req.ContentLength = expectedLength
  72         if expectedLength > 0 {
  73                 req.Body = ioutil.NopCloser(body)
  74         } else {
  75                 // "For client requests, a value of 0 means unknown if
  76                 // Body is not nil."  In this case we do want the body
  77                 // to be empty, so don't set req.Body.
  78         }
  79
  80         req.Header.Add("Authorization", fmt.Sprintf("OAuth2 %s", 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
  84         var resp *http.Response
  85         if resp, err = this.httpClient().Do(req); err != nil {
  86                 DebugPrintf("DEBUG: [%08x] Upload failed %v error: %v", requestID, url, err.Error())
  87                 upload_status <- uploadStatus{err, url, 0, 0, ""}
  88                 return
  89         }
  90
  91         rep := 1
  92         if xr := resp.Header.Get(X_Keep_Replicas_Stored); xr != "" {
  93                 fmt.Sscanf(xr, "%d", &rep)
  94         }
  95
  96         defer resp.Body.Close()
  97         defer io.Copy(ioutil.Discard, resp.Body)
  98
  99         respbody, err2 := ioutil.ReadAll(&io.LimitedReader{R: resp.Body, N: 4096})
 100         response := strings.TrimSpace(string(respbody))
 101         if err2 != nil && err2 != io.EOF {
 102                 DebugPrintf("DEBUG: [%08x] Upload %v error: %v response: %v", requestID, url, err2.Error(), response)
 103                 upload_status <- uploadStatus{err2, url, resp.StatusCode, rep, response}
 104         } else if resp.StatusCode == http.StatusOK {
 105                 DebugPrintf("DEBUG: [%08x] Upload %v success", requestID, url)
 106                 upload_status <- uploadStatus{nil, url, resp.StatusCode, rep, response}
 107         } else {
 108                 if resp.StatusCode >= 300 && response == "" {
 109                         response = resp.Status
 110                 }
 111                 DebugPrintf("DEBUG: [%08x] Upload %v error: %v response: %v", requestID, url, resp.StatusCode, response)
 112                 upload_status <- uploadStatus{errors.New(resp.Status), url, resp.StatusCode, rep, response}
 113         }
 114 }
 115
 116 func (this *KeepClient) putReplicas(
 117         hash string,
 118         getReader func() io.Reader,
 119         expectedLength int64) (locator string, replicas int, err error) {
 120
 121         // Generate an arbitrary ID to identify this specific
 122         // transaction in debug logs.
 123         requestID := rand.Int31()
 124
 125         // Calculate the ordering for uploading to servers
 126         sv := NewRootSorter(this.WritableLocalRoots(), hash).GetSortedRoots()
 127
 128         // The next server to try contacting
 129         next_server := 0
 130
 131         // The number of active writers
 132         active := 0
 133
 134         // Used to communicate status from the upload goroutines
 135         upload_status := make(chan uploadStatus)
 136         defer func() {
 137                 // Wait for any abandoned uploads (e.g., we started
 138                 // two uploads and the first replied with replicas=2)
 139                 // to finish before closing the status channel.
 140                 go func() {
 141                         for active > 0 {
 142                                 <-upload_status
 143                         }
 144                         close(upload_status)
 145                 }()
 146         }()
 147
 148         replicasDone := 0
 149         replicasTodo := this.Want_replicas
 150
 151         replicasPerThread := this.replicasPerService
 152         if replicasPerThread < 1 {
 153                 // unlimited or unknown
 154                 replicasPerThread = replicasTodo
 155         }
 156
 157         retriesRemaining := 1 + this.Retries
 158         var retryServers []string
 159
 160         lastError := make(map[string]string)
 161
 162         for retriesRemaining > 0 {
 163                 retriesRemaining -= 1
 164                 next_server = 0
 165                 retryServers = []string{}
 166                 for replicasTodo > 0 {
 167                         for active*replicasPerThread < replicasTodo {
 168                                 // Start some upload requests
 169                                 if next_server < len(sv) {
 170                                         DebugPrintf("DEBUG: [%08x] Begin upload %s to %s", requestID, hash, sv[next_server])
 171                                         go this.uploadToKeepServer(sv[next_server], hash, getReader(), upload_status, expectedLength, requestID)
 172                                         next_server += 1
 173                                         active += 1
 174                                 } else {
 175                                         if active == 0 && retriesRemaining == 0 {
 176                                                 msg := "Could not write sufficient replicas: "
 177                                                 for _, resp := range lastError {
 178                                                         msg += resp + "; "
 179                                                 }
 180                                                 msg = msg[:len(msg)-2]
 181                                                 return locator, replicasDone, InsufficientReplicasError(errors.New(msg))
 182                                         } else {
 183                                                 break
 184                                         }
 185                                 }
 186                         }
 187                         DebugPrintf("DEBUG: [%08x] Replicas remaining to write: %v active uploads: %v",
 188                                 requestID, 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 }