git.m6w6.name Git - awesomized/libmemcached/blob - libmemcached/hosts.cc

   1 /*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
   2  *
   3  *  Libmemcached library
   4  *
   5  *  Copyright (C) 2011 Data Differential, http://datadifferential.com/
   6  *  Copyright (C) 2006-2010 Brian Aker All rights reserved.
   7  *
   8  *  Redistribution and use in source and binary forms, with or without
   9  *  modification, are permitted provided that the following conditions are
  10  *  met:
  11  *
  12  *      * Redistributions of source code must retain the above copyright
  13  *  notice, this list of conditions and the following disclaimer.
  14  *
  15  *      * Redistributions in binary form must reproduce the above
  16  *  copyright notice, this list of conditions and the following disclaimer
  17  *  in the documentation and/or other materials provided with the
  18  *  distribution.
  19  *
  20  *      * The names of its contributors may not be used to endorse or
  21  *  promote products derived from this software without specific prior
  22  *  written permission.
  23  *
  24  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  25  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  26  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  27  *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  28  *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  29  *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  30  *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  31  *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  32  *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  34  *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  */
  37
  38 #include <libmemcached/common.h>
  39
  40 #include <cmath>
  41 #include <sys/time.h>
  42
  43 /* Protoypes (static) */
  44 static memcached_return_t update_continuum(memcached_st *ptr);
  45
  46 static int compare_servers(const void *p1, const void *p2)
  47 {
  48   memcached_server_instance_st a= (memcached_server_instance_st)p1;
  49   memcached_server_instance_st b= (memcached_server_instance_st)p2;
  50
  51   int return_value= strcmp(a->hostname, b->hostname);
  52
  53   if (return_value == 0)
  54   {
  55     return_value= int(a->port() - b->port());
  56   }
  57
  58   return return_value;
  59 }
  60
  61 static void sort_hosts(memcached_st *ptr)
  62 {
  63   if (memcached_server_count(ptr))
  64   {
  65     qsort(memcached_instance_list(ptr), memcached_server_count(ptr), sizeof(org::libmemcached::Instance), compare_servers);
  66   }
  67 }
  68
  69
  70 memcached_return_t run_distribution(memcached_st *ptr)
  71 {
  72   if (ptr->flags.use_sort_hosts)
  73   {
  74     sort_hosts(ptr);
  75   }
  76
  77   switch (ptr->distribution)
  78   {
  79   case MEMCACHED_DISTRIBUTION_CONSISTENT:
  80   case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA:
  81   case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY:
  82   case MEMCACHED_DISTRIBUTION_CONSISTENT_WEIGHTED:
  83     return update_continuum(ptr);
  84
  85   case MEMCACHED_DISTRIBUTION_VIRTUAL_BUCKET:
  86   case MEMCACHED_DISTRIBUTION_MODULA:
  87     break;
  88
  89   case MEMCACHED_DISTRIBUTION_RANDOM:
  90     srandom((uint32_t) time(NULL));
  91     break;
  92
  93   case MEMCACHED_DISTRIBUTION_CONSISTENT_MAX:
  94   default:
  95     assert_msg(0, "Invalid distribution type passed to run_distribution()");
  96   }
  97
  98   return MEMCACHED_SUCCESS;
  99 }
 100
 101 static uint32_t ketama_server_hash(const char *key, size_t key_length, uint32_t alignment)
 102 {
 103   unsigned char results[16];
 104
 105   libhashkit_md5_signature((unsigned char*)key, key_length, results);
 106
 107   return ((uint32_t) (results[3 + alignment * 4] & 0xFF) << 24)
 108     | ((uint32_t) (results[2 + alignment * 4] & 0xFF) << 16)
 109     | ((uint32_t) (results[1 + alignment * 4] & 0xFF) << 8)
 110     | (results[0 + alignment * 4] & 0xFF);
 111 }
 112
 113 static int continuum_item_cmp(const void *t1, const void *t2)
 114 {
 115   memcached_continuum_item_st *ct1= (memcached_continuum_item_st *)t1;
 116   memcached_continuum_item_st *ct2= (memcached_continuum_item_st *)t2;
 117
 118   /* Why 153? Hmmm... */
 119   WATCHPOINT_ASSERT(ct1->value != 153);
 120   if (ct1->value == ct2->value)
 121     return 0;
 122   else if (ct1->value > ct2->value)
 123     return 1;
 124   else
 125     return -1;
 126 }
 127
 128 static memcached_return_t update_continuum(memcached_st *ptr)
 129 {
 130   uint32_t continuum_index= 0;
 131   uint32_t pointer_counter= 0;
 132   uint32_t pointer_per_server= MEMCACHED_POINTS_PER_SERVER;
 133   uint32_t pointer_per_hash= 1;
 134   uint32_t live_servers= 0;
 135   struct timeval now;
 136
 137   if (gettimeofday(&now, NULL))
 138   {
 139     return memcached_set_errno(*ptr, errno, MEMCACHED_AT);
 140   }
 141
 142   org::libmemcached::Instance* list= memcached_instance_list(ptr);
 143
 144   /* count live servers (those without a retry delay set) */
 145   bool is_auto_ejecting= _is_auto_eject_host(ptr);
 146   if (is_auto_ejecting)
 147   {
 148     live_servers= 0;
 149     ptr->ketama.next_distribution_rebuild= 0;
 150     for (uint32_t host_index= 0; host_index < memcached_server_count(ptr); ++host_index)
 151     {
 152       if (list[host_index].next_retry <= now.tv_sec)
 153       {
 154         live_servers++;
 155       }
 156       else
 157       {
 158         if (ptr->ketama.next_distribution_rebuild == 0 or list[host_index].next_retry < ptr->ketama.next_distribution_rebuild)
 159         {
 160           ptr->ketama.next_distribution_rebuild= list[host_index].next_retry;
 161         }
 162       }
 163     }
 164   }
 165   else
 166   {
 167     live_servers= memcached_server_count(ptr);
 168   }
 169
 170   uint64_t is_ketama_weighted= memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_KETAMA_WEIGHTED);
 171   uint32_t points_per_server= (uint32_t) (is_ketama_weighted ? MEMCACHED_POINTS_PER_SERVER_KETAMA : MEMCACHED_POINTS_PER_SERVER);
 172
 173   if (live_servers == 0)
 174   {
 175     return MEMCACHED_SUCCESS;
 176   }
 177
 178   if (live_servers > ptr->ketama.continuum_count)
 179   {
 180     memcached_continuum_item_st *new_ptr;
 181
 182     new_ptr= libmemcached_xrealloc(ptr, ptr->ketama.continuum, (live_servers + MEMCACHED_CONTINUUM_ADDITION) * points_per_server, memcached_continuum_item_st);
 183
 184     if (new_ptr == 0)
 185     {
 186       return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 187     }
 188
 189     ptr->ketama.continuum= new_ptr;
 190     ptr->ketama.continuum_count= live_servers + MEMCACHED_CONTINUUM_ADDITION;
 191   }
 192
 193   uint64_t total_weight= 0;
 194   if (is_ketama_weighted)
 195   {
 196     for (uint32_t host_index = 0; host_index < memcached_server_count(ptr); ++host_index)
 197     {
 198       if (is_auto_ejecting == false or list[host_index].next_retry <= now.tv_sec)
 199       {
 200         total_weight += list[host_index].weight;
 201       }
 202     }
 203   }
 204
 205   for (uint32_t host_index= 0; host_index < memcached_server_count(ptr); ++host_index)
 206   {
 207     if (is_auto_ejecting and list[host_index].next_retry > now.tv_sec)
 208     {
 209       continue;
 210     }
 211
 212     if (is_ketama_weighted)
 213     {
 214         float pct= (float)list[host_index].weight / (float)total_weight;
 215         pointer_per_server= (uint32_t) ((::floor((float) (pct * MEMCACHED_POINTS_PER_SERVER_KETAMA / 4 * (float)live_servers + 0.0000000001))) * 4);
 216         pointer_per_hash= 4;
 217         if (DEBUG)
 218         {
 219           printf("ketama_weighted:%s|%d|%llu|%u\n",
 220                  list[host_index].hostname,
 221                  list[host_index].port(),
 222                  (unsigned long long)list[host_index].weight,
 223                  pointer_per_server);
 224         }
 225     }
 226
 227
 228     if (ptr->distribution == MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY)
 229     {
 230       for (uint32_t pointer_index= 0;
 231            pointer_index < pointer_per_server / pointer_per_hash;
 232            pointer_index++)
 233       {
 234         char sort_host[1 +MEMCACHED_NI_MAXHOST +1 +MEMCACHED_NI_MAXSERV +1 + MEMCACHED_NI_MAXSERV ]= "";
 235         int sort_host_length;
 236
 237         // Spymemcached ketema key format is: hostname/ip:port-index
 238         // If hostname is not available then: /ip:port-index
 239         sort_host_length= snprintf(sort_host, sizeof(sort_host),
 240                                    "/%s:%u-%u",
 241                                    list[host_index].hostname,
 242                                    (uint32_t)list[host_index].port(),
 243                                    pointer_index);
 244
 245         if (size_t(sort_host_length) >= sizeof(sort_host) or sort_host_length < 0)
 246         {
 247           return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT,
 248                                      memcached_literal_param("snprintf(sizeof(sort_host))"));
 249         }
 250
 251         if (DEBUG)
 252         {
 253           fprintf(stdout, "update_continuum: key is %s\n", sort_host);
 254         }
 255
 256         if (is_ketama_weighted)
 257         {
 258           for (uint32_t x= 0; x < pointer_per_hash; x++)
 259           {
 260             uint32_t value= ketama_server_hash(sort_host, (size_t)sort_host_length, x);
 261             ptr->ketama.continuum[continuum_index].index= host_index;
 262             ptr->ketama.continuum[continuum_index++].value= value;
 263           }
 264         }
 265         else
 266         {
 267           uint32_t value= hashkit_digest(&ptr->hashkit, sort_host, (size_t)sort_host_length);
 268           ptr->ketama.continuum[continuum_index].index= host_index;
 269           ptr->ketama.continuum[continuum_index++].value= value;
 270         }
 271       }
 272     }
 273     else
 274     {
 275       for (uint32_t pointer_index= 1;
 276            pointer_index <= pointer_per_server / pointer_per_hash;
 277            pointer_index++)
 278       {
 279         char sort_host[MEMCACHED_NI_MAXHOST +1 +MEMCACHED_NI_MAXSERV +1 +MEMCACHED_NI_MAXSERV]= "";
 280         int sort_host_length;
 281
 282         if (list[host_index].port() == MEMCACHED_DEFAULT_PORT)
 283         {
 284           sort_host_length= snprintf(sort_host, sizeof(sort_host),
 285                                      "%s-%u",
 286                                      list[host_index].hostname,
 287                                      pointer_index - 1);
 288         }
 289         else
 290         {
 291           sort_host_length= snprintf(sort_host, sizeof(sort_host),
 292                                      "%s:%u-%u",
 293                                      list[host_index].hostname,
 294                                      (uint32_t)list[host_index].port(),
 295                                      pointer_index - 1);
 296         }
 297
 298         if (size_t(sort_host_length) >= sizeof(sort_host) or sort_host_length < 0)
 299         {
 300           return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT,
 301                                      memcached_literal_param("snprintf(sizeof(sort_host)))"));
 302         }
 303
 304         if (is_ketama_weighted)
 305         {
 306           for (uint32_t x = 0; x < pointer_per_hash; x++)
 307           {
 308             uint32_t value= ketama_server_hash(sort_host, (size_t)sort_host_length, x);
 309             ptr->ketama.continuum[continuum_index].index= host_index;
 310             ptr->ketama.continuum[continuum_index++].value= value;
 311           }
 312         }
 313         else
 314         {
 315           uint32_t value= hashkit_digest(&ptr->hashkit, sort_host, (size_t)sort_host_length);
 316           ptr->ketama.continuum[continuum_index].index= host_index;
 317           ptr->ketama.continuum[continuum_index++].value= value;
 318         }
 319       }
 320     }
 321
 322     pointer_counter+= pointer_per_server;
 323   }
 324
 325   WATCHPOINT_ASSERT(ptr);
 326   WATCHPOINT_ASSERT(ptr->ketama.continuum);
 327   WATCHPOINT_ASSERT(memcached_server_count(ptr) * MEMCACHED_POINTS_PER_SERVER <= MEMCACHED_CONTINUUM_SIZE);
 328   ptr->ketama.continuum_points_counter= pointer_counter;
 329   qsort(ptr->ketama.continuum, ptr->ketama.continuum_points_counter, sizeof(memcached_continuum_item_st), continuum_item_cmp);
 330
 331   if (DEBUG)
 332   {
 333     for (uint32_t pointer_index= 0; memcached_server_count(ptr) && pointer_index < ((live_servers * MEMCACHED_POINTS_PER_SERVER) - 1); pointer_index++)
 334     {
 335       WATCHPOINT_ASSERT(ptr->ketama.continuum[pointer_index].value <= ptr->ketama.continuum[pointer_index + 1].value);
 336     }
 337   }
 338
 339   return MEMCACHED_SUCCESS;
 340 }
 341
 342 static memcached_return_t server_add(memcached_st *ptr,
 343                                      const memcached_string_t& hostname,
 344                                      in_port_t port,
 345                                      uint32_t weight,
 346                                      memcached_connection_t type)
 347 {
 348   assert_msg(ptr, "Programmer mistake, somehow server_add() was passed a NULL memcached_st");
 349
 350   org::libmemcached::Instance* new_host_list= libmemcached_xrealloc(ptr, memcached_instance_list(ptr), (ptr->number_of_hosts + 1), org::libmemcached::Instance);
 351
 352   if (new_host_list == NULL)
 353   {
 354     return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
 355   }
 356
 357   memcached_instance_set(ptr, new_host_list);
 358
 359   /* TODO: Check return type */
 360   org::libmemcached::Instance* instance= memcached_instance_fetch(ptr, memcached_server_count(ptr));
 361
 362   if (__instance_create_with(ptr, instance, hostname, port, weight, type) == NULL)
 363   {
 364     return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
 365   }
 366
 367   if (weight > 1)
 368   {
 369     ptr->ketama.weighted= true;
 370   }
 371
 372   ptr->number_of_hosts++;
 373
 374   return run_distribution(ptr);
 375 }
 376
 377
 378 memcached_return_t memcached_server_push(memcached_st *ptr, const memcached_server_list_st list)
 379 {
 380   if (list == NULL)
 381   {
 382     return MEMCACHED_SUCCESS;
 383   }
 384
 385   uint32_t count= memcached_server_list_count(list);
 386
 387   org::libmemcached::Instance* new_host_list= libmemcached_xrealloc(ptr, memcached_instance_list(ptr), (count + memcached_server_count(ptr)), org::libmemcached::Instance);
 388
 389   if (new_host_list == NULL)
 390   {
 391     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 392   }
 393
 394   memcached_instance_set(ptr, new_host_list);
 395
 396   for (uint32_t x= 0; x < count; x++)
 397   {
 398     WATCHPOINT_ASSERT(list[x].hostname[0] != 0);
 399
 400     // We have extended the array, and now we will find it, and use it.
 401     org::libmemcached::Instance* instance= memcached_instance_fetch(ptr, memcached_server_count(ptr));
 402     WATCHPOINT_ASSERT(instance);
 403
 404     memcached_string_t hostname= { memcached_string_make_from_cstr(list[x].hostname) };
 405     if (__instance_create_with(ptr, instance,
 406                                hostname,
 407                                list[x].port, list[x].weight, list[x].type) == NULL)
 408     {
 409       return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
 410     }
 411
 412     if (list[x].weight > 1)
 413     {
 414       ptr->ketama.weighted= true;
 415     }
 416
 417     ptr->number_of_hosts++;
 418   }
 419
 420   return run_distribution(ptr);
 421 }
 422
 423 memcached_return_t memcached_instance_push(memcached_st *ptr, const struct org::libmemcached::Instance* list, uint32_t number_of_hosts)
 424 {
 425   if (list == NULL)
 426   {
 427     return MEMCACHED_SUCCESS;
 428   }
 429
 430   org::libmemcached::Instance* new_host_list= libmemcached_xrealloc(ptr, memcached_instance_list(ptr), (number_of_hosts +memcached_server_count(ptr)), org::libmemcached::Instance);
 431
 432   if (new_host_list == NULL)
 433   {
 434     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 435   }
 436
 437   memcached_instance_set(ptr, new_host_list);
 438
 439   for (uint32_t x= 0; x < number_of_hosts; x++)
 440   {
 441
 442     WATCHPOINT_ASSERT(list[x].hostname[0] != 0);
 443
 444     // We have extended the array, and now we will find it, and use it.
 445     org::libmemcached::Instance* instance= memcached_instance_fetch(ptr, memcached_server_count(ptr));
 446     WATCHPOINT_ASSERT(instance);
 447
 448     memcached_string_t hostname= { memcached_string_make_from_cstr(list[x].hostname) };
 449     if (__instance_create_with(ptr, instance,
 450                                hostname,
 451                                list[x].port(), list[x].weight, list[x].type) == NULL)
 452     {
 453       return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
 454     }
 455
 456     if (list[x].weight > 1)
 457     {
 458       ptr->ketama.weighted= true;
 459     }
 460
 461     ptr->number_of_hosts++;
 462   }
 463
 464   return run_distribution(ptr);
 465 }
 466
 467 memcached_return_t memcached_server_add_unix_socket(memcached_st *ptr,
 468                                                     const char *filename)
 469 {
 470   return memcached_server_add_unix_socket_with_weight(ptr, filename, 0);
 471 }
 472
 473 memcached_return_t memcached_server_add_unix_socket_with_weight(memcached_st *ptr,
 474                                                                 const char *filename,
 475                                                                 uint32_t weight)
 476 {
 477   if (ptr == NULL)
 478   {
 479     return MEMCACHED_FAILURE;
 480   }
 481
 482   memcached_string_t _filename= { memcached_string_make_from_cstr(filename) };
 483   if (memcached_is_valid_servername(_filename) == false)
 484   {
 485     memcached_set_error(*ptr, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT, memcached_literal_param("Invalid filename for socket provided"));
 486   }
 487
 488   return server_add(ptr, _filename, 0, weight, MEMCACHED_CONNECTION_UNIX_SOCKET);
 489 }
 490
 491 memcached_return_t memcached_server_add_udp(memcached_st *ptr,
 492                                             const char *hostname,
 493                                             in_port_t port)
 494 {
 495   return memcached_server_add_udp_with_weight(ptr, hostname, port, 0);
 496 }
 497
 498 memcached_return_t memcached_server_add_udp_with_weight(memcached_st *ptr,
 499                                                         const char *,
 500                                                         in_port_t,
 501                                                         uint32_t)
 502 {
 503   if (ptr == NULL)
 504   {
 505     return MEMCACHED_INVALID_ARGUMENTS;
 506   }
 507
 508   return memcached_set_error(*ptr, MEMCACHED_DEPRECATED, MEMCACHED_AT);
 509 }
 510
 511 memcached_return_t memcached_server_add(memcached_st *ptr,
 512                                         const char *hostname,
 513                                         in_port_t port)
 514 {
 515   return memcached_server_add_with_weight(ptr, hostname, port, 0);
 516 }
 517
 518 memcached_return_t memcached_server_add_with_weight(memcached_st *ptr,
 519                                                     const char *hostname,
 520                                                     in_port_t port,
 521                                                     uint32_t weight)
 522 {
 523   if (ptr == NULL)
 524   {
 525     return MEMCACHED_INVALID_ARGUMENTS;
 526   }
 527
 528   if (port == 0)
 529   {
 530     port= MEMCACHED_DEFAULT_PORT;
 531   }
 532
 533   size_t hostname_length= hostname ? strlen(hostname) : 0;
 534   if (hostname_length == 0)
 535   {
 536     hostname= "localhost";
 537     hostname_length= memcached_literal_param_size("localhost");
 538   }
 539
 540   memcached_string_t _hostname= { hostname, hostname_length };
 541
 542   if (memcached_is_valid_servername(_hostname) == false)
 543   {
 544     return memcached_set_error(*ptr, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT, memcached_literal_param("Invalid hostname provided"));
 545   }
 546
 547   return server_add(ptr, _hostname, port, weight, _hostname.c_str[0] == '/' ? MEMCACHED_CONNECTION_UNIX_SOCKET  : MEMCACHED_CONNECTION_TCP);
 548 }
 549
 550 memcached_return_t memcached_server_add_parsed(memcached_st *ptr,
 551                                                const char *hostname,
 552                                                size_t hostname_length,
 553                                                in_port_t port,
 554                                                uint32_t weight)
 555 {
 556   char buffer[NI_MAXHOST];
 557
 558   memcpy(buffer, hostname, hostname_length);
 559   buffer[hostname_length]= 0;
 560
 561   memcached_string_t _hostname= { buffer, hostname_length };
 562
 563   return server_add(ptr, _hostname,
 564                     port,
 565                     weight,
 566                     MEMCACHED_CONNECTION_TCP);
 567 }