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[m6w6/libmemcached] / 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 }
Resurrection of libmemcached https://launchpad.net/libmemcached