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   {
 122     return 0;
 123   }
 124   else if (ct1->value > ct2->value)
 125   {
 126     return 1;
 127   }
 128   else
 129   {
 130     return -1;
 131   }
 132 }
 133
 134 static memcached_return_t update_continuum(memcached_st *ptr)
 135 {
 136   uint32_t continuum_index= 0;
 137   uint32_t pointer_counter= 0;
 138   uint32_t pointer_per_server= MEMCACHED_POINTS_PER_SERVER;
 139   uint32_t pointer_per_hash= 1;
 140   uint32_t live_servers= 0;
 141   struct timeval now;
 142
 143   if (gettimeofday(&now, NULL))
 144   {
 145     return memcached_set_errno(*ptr, errno, MEMCACHED_AT);
 146   }
 147
 148   org::libmemcached::Instance* list= memcached_instance_list(ptr);
 149
 150   /* count live servers (those without a retry delay set) */
 151   bool is_auto_ejecting= _is_auto_eject_host(ptr);
 152   if (is_auto_ejecting)
 153   {
 154     live_servers= 0;
 155     ptr->ketama.next_distribution_rebuild= 0;
 156     for (uint32_t host_index= 0; host_index < memcached_server_count(ptr); ++host_index)
 157     {
 158       if (list[host_index].next_retry <= now.tv_sec)
 159       {
 160         live_servers++;
 161       }
 162       else
 163       {
 164         if (ptr->ketama.next_distribution_rebuild == 0 or list[host_index].next_retry < ptr->ketama.next_distribution_rebuild)
 165         {
 166           ptr->ketama.next_distribution_rebuild= list[host_index].next_retry;
 167         }
 168       }
 169     }
 170   }
 171   else
 172   {
 173     live_servers= memcached_server_count(ptr);
 174   }
 175
 176   uint32_t points_per_server= (uint32_t) (memcached_is_weighted_ketama(ptr) ? MEMCACHED_POINTS_PER_SERVER_KETAMA : MEMCACHED_POINTS_PER_SERVER);
 177
 178   if (live_servers == 0)
 179   {
 180     return MEMCACHED_SUCCESS;
 181   }
 182
 183   if (live_servers > ptr->ketama.continuum_count)
 184   {
 185     memcached_continuum_item_st *new_ptr;
 186
 187     new_ptr= libmemcached_xrealloc(ptr, ptr->ketama.continuum, (live_servers + MEMCACHED_CONTINUUM_ADDITION) * points_per_server, memcached_continuum_item_st);
 188
 189     if (new_ptr == 0)
 190     {
 191       return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 192     }
 193
 194     ptr->ketama.continuum= new_ptr;
 195     ptr->ketama.continuum_count= live_servers + MEMCACHED_CONTINUUM_ADDITION;
 196   }
 197
 198   uint64_t total_weight= 0;
 199   if (memcached_is_weighted_ketama(ptr))
 200   {
 201     for (uint32_t host_index = 0; host_index < memcached_server_count(ptr); ++host_index)
 202     {
 203       if (is_auto_ejecting == false or list[host_index].next_retry <= now.tv_sec)
 204       {
 205         total_weight += list[host_index].weight;
 206       }
 207     }
 208   }
 209
 210   for (uint32_t host_index= 0; host_index < memcached_server_count(ptr); ++host_index)
 211   {
 212     if (is_auto_ejecting and list[host_index].next_retry > now.tv_sec)
 213     {
 214       continue;
 215     }
 216
 217     if (memcached_is_weighted_ketama(ptr))
 218     {
 219         float pct= (float)list[host_index].weight / (float)total_weight;
 220         pointer_per_server= (uint32_t) ((::floor((float) (pct * MEMCACHED_POINTS_PER_SERVER_KETAMA / 4 * (float)live_servers + 0.0000000001))) * 4);
 221         pointer_per_hash= 4;
 222         if (DEBUG)
 223         {
 224           printf("ketama_weighted:%s|%d|%llu|%u\n",
 225                  list[host_index].hostname,
 226                  list[host_index].port(),
 227                  (unsigned long long)list[host_index].weight,
 228                  pointer_per_server);
 229         }
 230     }
 231
 232
 233     if (ptr->distribution == MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY)
 234     {
 235       for (uint32_t pointer_index= 0;
 236            pointer_index < pointer_per_server / pointer_per_hash;
 237            pointer_index++)
 238       {
 239         char sort_host[1 +MEMCACHED_NI_MAXHOST +1 +MEMCACHED_NI_MAXSERV +1 + MEMCACHED_NI_MAXSERV ]= "";
 240         int sort_host_length;
 241
 242         // Spymemcached ketema key format is: hostname/ip:port-index
 243         // If hostname is not available then: /ip:port-index
 244         sort_host_length= snprintf(sort_host, sizeof(sort_host),
 245                                    "/%s:%u-%u",
 246                                    list[host_index].hostname,
 247                                    (uint32_t)list[host_index].port(),
 248                                    pointer_index);
 249
 250         if (size_t(sort_host_length) >= sizeof(sort_host) or sort_host_length < 0)
 251         {
 252           return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT,
 253                                      memcached_literal_param("snprintf(sizeof(sort_host))"));
 254         }
 255
 256         if (DEBUG)
 257         {
 258           fprintf(stdout, "update_continuum: key is %s\n", sort_host);
 259         }
 260
 261         if (memcached_is_weighted_ketama(ptr))
 262         {
 263           for (uint32_t x= 0; x < pointer_per_hash; x++)
 264           {
 265             uint32_t value= ketama_server_hash(sort_host, (size_t)sort_host_length, x);
 266             ptr->ketama.continuum[continuum_index].index= host_index;
 267             ptr->ketama.continuum[continuum_index++].value= value;
 268           }
 269         }
 270         else
 271         {
 272           uint32_t value= hashkit_digest(&ptr->hashkit, sort_host, (size_t)sort_host_length);
 273           ptr->ketama.continuum[continuum_index].index= host_index;
 274           ptr->ketama.continuum[continuum_index++].value= value;
 275         }
 276       }
 277     }
 278     else
 279     {
 280       for (uint32_t pointer_index= 1;
 281            pointer_index <= pointer_per_server / pointer_per_hash;
 282            pointer_index++)
 283       {
 284         char sort_host[MEMCACHED_NI_MAXHOST +1 +MEMCACHED_NI_MAXSERV +1 +MEMCACHED_NI_MAXSERV]= "";
 285         int sort_host_length;
 286
 287         if (list[host_index].port() == MEMCACHED_DEFAULT_PORT)
 288         {
 289           sort_host_length= snprintf(sort_host, sizeof(sort_host),
 290                                      "%s-%u",
 291                                      list[host_index].hostname,
 292                                      pointer_index - 1);
 293         }
 294         else
 295         {
 296           sort_host_length= snprintf(sort_host, sizeof(sort_host),
 297                                      "%s:%u-%u",
 298                                      list[host_index].hostname,
 299                                      (uint32_t)list[host_index].port(),
 300                                      pointer_index - 1);
 301         }
 302
 303         if (size_t(sort_host_length) >= sizeof(sort_host) or sort_host_length < 0)
 304         {
 305           return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT,
 306                                      memcached_literal_param("snprintf(sizeof(sort_host)))"));
 307         }
 308
 309         if (memcached_is_weighted_ketama(ptr))
 310         {
 311           for (uint32_t x = 0; x < pointer_per_hash; x++)
 312           {
 313             uint32_t value= ketama_server_hash(sort_host, (size_t)sort_host_length, x);
 314             ptr->ketama.continuum[continuum_index].index= host_index;
 315             ptr->ketama.continuum[continuum_index++].value= value;
 316           }
 317         }
 318         else
 319         {
 320           uint32_t value= hashkit_digest(&ptr->hashkit, sort_host, (size_t)sort_host_length);
 321           ptr->ketama.continuum[continuum_index].index= host_index;
 322           ptr->ketama.continuum[continuum_index++].value= value;
 323         }
 324       }
 325     }
 326
 327     pointer_counter+= pointer_per_server;
 328   }
 329
 330   WATCHPOINT_ASSERT(ptr);
 331   WATCHPOINT_ASSERT(ptr->ketama.continuum);
 332   WATCHPOINT_ASSERT(memcached_server_count(ptr) * MEMCACHED_POINTS_PER_SERVER <= MEMCACHED_CONTINUUM_SIZE);
 333   ptr->ketama.continuum_points_counter= pointer_counter;
 334   qsort(ptr->ketama.continuum, ptr->ketama.continuum_points_counter, sizeof(memcached_continuum_item_st), continuum_item_cmp);
 335
 336   if (DEBUG)
 337   {
 338     for (uint32_t pointer_index= 0; memcached_server_count(ptr) && pointer_index < ((live_servers * MEMCACHED_POINTS_PER_SERVER) - 1); pointer_index++)
 339     {
 340       WATCHPOINT_ASSERT(ptr->ketama.continuum[pointer_index].value <= ptr->ketama.continuum[pointer_index + 1].value);
 341     }
 342   }
 343
 344   return MEMCACHED_SUCCESS;
 345 }
 346
 347 static memcached_return_t server_add(memcached_st *ptr,
 348                                      const memcached_string_t& hostname,
 349                                      in_port_t port,
 350                                      uint32_t weight,
 351                                      memcached_connection_t type)
 352 {
 353   assert_msg(ptr, "Programmer mistake, somehow server_add() was passed a NULL memcached_st");
 354
 355   if (ptr->number_of_hosts)
 356   {
 357     assert(memcached_instance_list(ptr));
 358   }
 359
 360   if (memcached_instance_list(ptr))
 361   {
 362     assert(ptr->number_of_hosts);
 363   }
 364
 365   uint32_t host_list_size= ptr->number_of_hosts +1;
 366   org::libmemcached::Instance* new_host_list= libmemcached_xrealloc(ptr, memcached_instance_list(ptr), host_list_size, org::libmemcached::Instance);
 367
 368   if (new_host_list == NULL)
 369   {
 370     return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
 371   }
 372
 373   memcached_instance_set(ptr, new_host_list, host_list_size);
 374   assert(ptr->number_of_hosts == host_list_size);
 375
 376   /* TODO: Check return type */
 377   org::libmemcached::Instance* instance= memcached_instance_fetch(ptr, memcached_server_count(ptr) -1);
 378
 379   if (__instance_create_with(ptr, instance, hostname, port, weight, type) == NULL)
 380   {
 381     return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
 382   }
 383
 384   if (weight > 1)
 385   {
 386     if (memcached_is_consistent_distribution(ptr))
 387     {
 388       memcached_set_weighted_ketama(ptr, true);
 389     }
 390   }
 391
 392   return run_distribution(ptr);
 393 }
 394
 395
 396 memcached_return_t memcached_server_push(memcached_st *ptr, const memcached_server_list_st list)
 397 {
 398   if (list == NULL)
 399   {
 400     return MEMCACHED_SUCCESS;
 401   }
 402
 403   uint32_t original_host_size= memcached_server_count(ptr);
 404   uint32_t count= memcached_server_list_count(list);
 405   uint32_t host_list_size= count +original_host_size;
 406
 407   org::libmemcached::Instance* new_host_list= libmemcached_xrealloc(ptr, memcached_instance_list(ptr), host_list_size, org::libmemcached::Instance);
 408
 409   if (new_host_list == NULL)
 410   {
 411     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 412   }
 413
 414   memcached_instance_set(ptr, new_host_list, host_list_size);
 415
 416   ptr->state.is_parsing= true;
 417   for (uint32_t x= 0; x < count; ++x, ++original_host_size)
 418   {
 419     WATCHPOINT_ASSERT(list[x].hostname[0] != 0);
 420
 421     // We have extended the array, and now we will find it, and use it.
 422     org::libmemcached::Instance* instance= memcached_instance_fetch(ptr, original_host_size);
 423     WATCHPOINT_ASSERT(instance);
 424
 425     memcached_string_t hostname= { memcached_string_make_from_cstr(list[x].hostname) };
 426     if (__instance_create_with(ptr, instance,
 427                                hostname,
 428                                list[x].port, list[x].weight, list[x].type) == NULL)
 429     {
 430       ptr->state.is_parsing= false;
 431       return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
 432     }
 433
 434     if (list[x].weight > 1)
 435     {
 436       memcached_set_weighted_ketama(ptr, true);
 437     }
 438   }
 439   ptr->state.is_parsing= false;
 440
 441   return run_distribution(ptr);
 442 }
 443
 444 memcached_return_t memcached_instance_push(memcached_st *ptr, const struct org::libmemcached::Instance* list, uint32_t number_of_hosts)
 445 {
 446   if (list == NULL)
 447   {
 448     return MEMCACHED_SUCCESS;
 449   }
 450
 451   uint32_t original_host_size= memcached_server_count(ptr);
 452   uint32_t host_list_size= number_of_hosts +original_host_size;
 453   org::libmemcached::Instance* new_host_list= libmemcached_xrealloc(ptr, memcached_instance_list(ptr), host_list_size, org::libmemcached::Instance);
 454
 455   if (new_host_list == NULL)
 456   {
 457     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 458   }
 459
 460   memcached_instance_set(ptr, new_host_list, host_list_size);
 461
 462   // We don't bother with lookups for this operation
 463   ptr->state.is_parsing= true;
 464
 465   // We use original_host_size since size will now point to the first new
 466   // instance allocated.
 467   for (uint32_t x= 0; x < number_of_hosts; ++x, ++original_host_size)
 468   {
 469     WATCHPOINT_ASSERT(list[x].hostname[0] != 0);
 470
 471     // We have extended the array, and now we will find it, and use it.
 472     org::libmemcached::Instance* instance= memcached_instance_fetch(ptr, original_host_size);
 473     WATCHPOINT_ASSERT(instance);
 474
 475     memcached_string_t hostname= { memcached_string_make_from_cstr(list[x].hostname) };
 476     if (__instance_create_with(ptr, instance,
 477                                hostname,
 478                                list[x].port(), list[x].weight, list[x].type) == NULL)
 479     {
 480       ptr->state.is_parsing= false;
 481       return memcached_set_error(*ptr, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
 482     }
 483
 484     if (list[x].weight > 1)
 485     {
 486       memcached_set_weighted_ketama(ptr, true);
 487     }
 488   }
 489   ptr->state.is_parsing= false;
 490
 491   return run_distribution(ptr);
 492 }
 493
 494 memcached_return_t memcached_server_add_unix_socket(memcached_st *ptr,
 495                                                     const char *filename)
 496 {
 497   return memcached_server_add_unix_socket_with_weight(ptr, filename, 0);
 498 }
 499
 500 memcached_return_t memcached_server_add_unix_socket_with_weight(memcached_st *ptr,
 501                                                                 const char *filename,
 502                                                                 uint32_t weight)
 503 {
 504   if (ptr == NULL)
 505   {
 506     return MEMCACHED_FAILURE;
 507   }
 508
 509   memcached_string_t _filename= { memcached_string_make_from_cstr(filename) };
 510   if (memcached_is_valid_servername(_filename) == false)
 511   {
 512     memcached_set_error(*ptr, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT, memcached_literal_param("Invalid filename for socket provided"));
 513   }
 514
 515   return server_add(ptr, _filename, 0, weight, MEMCACHED_CONNECTION_UNIX_SOCKET);
 516 }
 517
 518 memcached_return_t memcached_server_add_udp(memcached_st *ptr,
 519                                             const char *hostname,
 520                                             in_port_t port)
 521 {
 522   return memcached_server_add_udp_with_weight(ptr, hostname, port, 0);
 523 }
 524
 525 memcached_return_t memcached_server_add_udp_with_weight(memcached_st *ptr,
 526                                                         const char *,
 527                                                         in_port_t,
 528                                                         uint32_t)
 529 {
 530   if (ptr == NULL)
 531   {
 532     return MEMCACHED_INVALID_ARGUMENTS;
 533   }
 534
 535   return memcached_set_error(*ptr, MEMCACHED_DEPRECATED, MEMCACHED_AT);
 536 }
 537
 538 memcached_return_t memcached_server_add(memcached_st *ptr,
 539                                         const char *hostname,
 540                                         in_port_t port)
 541 {
 542   return memcached_server_add_with_weight(ptr, hostname, port, 0);
 543 }
 544
 545 memcached_return_t memcached_server_add_with_weight(memcached_st *ptr,
 546                                                     const char *hostname,
 547                                                     in_port_t port,
 548                                                     uint32_t weight)
 549 {
 550   if (ptr == NULL)
 551   {
 552     return MEMCACHED_INVALID_ARGUMENTS;
 553   }
 554
 555   if (port == 0)
 556   {
 557     port= MEMCACHED_DEFAULT_PORT;
 558   }
 559
 560   size_t hostname_length= hostname ? strlen(hostname) : 0;
 561   if (hostname_length == 0)
 562   {
 563     hostname= "localhost";
 564     hostname_length= memcached_literal_param_size("localhost");
 565   }
 566
 567   memcached_string_t _hostname= { hostname, hostname_length };
 568
 569   if (memcached_is_valid_servername(_hostname) == false)
 570   {
 571     return memcached_set_error(*ptr, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT, memcached_literal_param("Invalid hostname provided"));
 572   }
 573
 574   return server_add(ptr, _hostname, port, weight, _hostname.c_str[0] == '/' ? MEMCACHED_CONNECTION_UNIX_SOCKET  : MEMCACHED_CONNECTION_TCP);
 575 }
 576
 577 memcached_return_t memcached_server_add_parsed(memcached_st *ptr,
 578                                                const char *hostname,
 579                                                size_t hostname_length,
 580                                                in_port_t port,
 581                                                uint32_t weight)
 582 {
 583   char buffer[NI_MAXHOST];
 584
 585   memcpy(buffer, hostname, hostname_length);
 586   buffer[hostname_length]= 0;
 587
 588   memcached_string_t _hostname= { buffer, hostname_length };
 589
 590   return server_add(ptr, _hostname,
 591                     port,
 592                     weight,
 593                     MEMCACHED_CONNECTION_TCP);
 594 }