1 /* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
5 * Copyright (C) 2011 Data Differential, http://datadifferential.com/
6 * Copyright (C) 2006-2010 Brian Aker All rights reserved.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are
12 * * Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
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
20 * * The names of its contributors may not be used to endorse or
21 * promote products derived from this software without specific prior
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.
38 #include <libmemcached/common.h>
43 /* Protoypes (static) */
44 static memcached_return_t
update_continuum(memcached_st
*ptr
);
46 static int compare_servers(const void *p1
, const void *p2
)
48 memcached_server_instance_st a
= (memcached_server_instance_st
)p1
;
49 memcached_server_instance_st b
= (memcached_server_instance_st
)p2
;
51 int return_value
= strcmp(a
->hostname
, b
->hostname
);
53 if (return_value
== 0)
55 return_value
= (int) (a
->port
- b
->port
);
61 static void sort_hosts(memcached_st
*ptr
)
63 if (memcached_server_count(ptr
))
65 memcached_server_write_instance_st instance
;
67 qsort(memcached_instance_list(ptr
), memcached_server_count(ptr
), sizeof(memcached_instance_st
), compare_servers
);
68 instance
= memcached_server_instance_fetch(ptr
, 0);
69 instance
->number_of_hosts
= memcached_server_count(ptr
);
74 memcached_return_t
run_distribution(memcached_st
*ptr
)
76 if (ptr
->flags
.use_sort_hosts
)
81 switch (ptr
->distribution
)
83 case MEMCACHED_DISTRIBUTION_CONSISTENT
:
84 case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA
:
85 case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY
:
86 case MEMCACHED_DISTRIBUTION_CONSISTENT_WEIGHTED
:
87 return update_continuum(ptr
);
89 case MEMCACHED_DISTRIBUTION_VIRTUAL_BUCKET
:
90 case MEMCACHED_DISTRIBUTION_MODULA
:
93 case MEMCACHED_DISTRIBUTION_RANDOM
:
94 srandom((uint32_t) time(NULL
));
97 case MEMCACHED_DISTRIBUTION_CONSISTENT_MAX
:
99 assert_msg(0, "Invalid distribution type passed to run_distribution()");
102 return MEMCACHED_SUCCESS
;
105 static uint32_t ketama_server_hash(const char *key
, size_t key_length
, uint32_t alignment
)
107 unsigned char results
[16];
109 libhashkit_md5_signature((unsigned char*)key
, key_length
, results
);
111 return ((uint32_t) (results
[3 + alignment
* 4] & 0xFF) << 24)
112 | ((uint32_t) (results
[2 + alignment
* 4] & 0xFF) << 16)
113 | ((uint32_t) (results
[1 + alignment
* 4] & 0xFF) << 8)
114 | (results
[0 + alignment
* 4] & 0xFF);
117 static int continuum_item_cmp(const void *t1
, const void *t2
)
119 memcached_continuum_item_st
*ct1
= (memcached_continuum_item_st
*)t1
;
120 memcached_continuum_item_st
*ct2
= (memcached_continuum_item_st
*)t2
;
122 /* Why 153? Hmmm... */
123 WATCHPOINT_ASSERT(ct1
->value
!= 153);
124 if (ct1
->value
== ct2
->value
)
126 else if (ct1
->value
> ct2
->value
)
132 static memcached_return_t
update_continuum(memcached_st
*ptr
)
134 uint32_t continuum_index
= 0;
135 uint32_t pointer_counter
= 0;
136 uint32_t pointer_per_server
= MEMCACHED_POINTS_PER_SERVER
;
137 uint32_t pointer_per_hash
= 1;
138 uint32_t live_servers
= 0;
141 if (gettimeofday(&now
, NULL
))
143 return memcached_set_errno(*ptr
, errno
, MEMCACHED_AT
);
146 memcached_instance_st
*list
= memcached_instance_list(ptr
);
148 /* count live servers (those without a retry delay set) */
149 bool is_auto_ejecting
= _is_auto_eject_host(ptr
);
150 if (is_auto_ejecting
)
153 ptr
->ketama
.next_distribution_rebuild
= 0;
154 for (uint32_t host_index
= 0; host_index
< memcached_server_count(ptr
); ++host_index
)
156 if (list
[host_index
].next_retry
<= now
.tv_sec
)
162 if (ptr
->ketama
.next_distribution_rebuild
== 0 or list
[host_index
].next_retry
< ptr
->ketama
.next_distribution_rebuild
)
164 ptr
->ketama
.next_distribution_rebuild
= list
[host_index
].next_retry
;
171 live_servers
= memcached_server_count(ptr
);
174 uint64_t is_ketama_weighted
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_KETAMA_WEIGHTED
);
175 uint32_t points_per_server
= (uint32_t) (is_ketama_weighted
? MEMCACHED_POINTS_PER_SERVER_KETAMA
: MEMCACHED_POINTS_PER_SERVER
);
177 if (not live_servers
)
179 return MEMCACHED_SUCCESS
;
182 if (live_servers
> ptr
->ketama
.continuum_count
)
184 memcached_continuum_item_st
*new_ptr
;
186 new_ptr
= libmemcached_xrealloc(ptr
, ptr
->ketama
.continuum
, (live_servers
+ MEMCACHED_CONTINUUM_ADDITION
) * points_per_server
, memcached_continuum_item_st
);
190 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
193 ptr
->ketama
.continuum
= new_ptr
;
194 ptr
->ketama
.continuum_count
= live_servers
+ MEMCACHED_CONTINUUM_ADDITION
;
197 uint64_t total_weight
= 0;
198 if (is_ketama_weighted
)
200 for (uint32_t host_index
= 0; host_index
< memcached_server_count(ptr
); ++host_index
)
202 if (is_auto_ejecting
== false or list
[host_index
].next_retry
<= now
.tv_sec
)
204 total_weight
+= list
[host_index
].weight
;
209 for (uint32_t host_index
= 0; host_index
< memcached_server_count(ptr
); ++host_index
)
211 if (is_auto_ejecting
and list
[host_index
].next_retry
> now
.tv_sec
)
216 if (is_ketama_weighted
)
218 float pct
= (float)list
[host_index
].weight
/ (float)total_weight
;
219 pointer_per_server
= (uint32_t) ((::floor((float) (pct
* MEMCACHED_POINTS_PER_SERVER_KETAMA
/ 4 * (float)live_servers
+ 0.0000000001))) * 4);
223 printf("ketama_weighted:%s|%d|%llu|%u\n",
224 list
[host_index
].hostname
,
225 list
[host_index
].port
,
226 (unsigned long long)list
[host_index
].weight
,
232 if (ptr
->distribution
== MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY
)
234 for (uint32_t pointer_index
= 0;
235 pointer_index
< pointer_per_server
/ pointer_per_hash
;
238 char sort_host
[1 +MEMCACHED_NI_MAXHOST
+1 +MEMCACHED_NI_MAXSERV
+1 + MEMCACHED_NI_MAXSERV
]= "";
239 int sort_host_length
;
241 // Spymemcached ketema key format is: hostname/ip:port-index
242 // If hostname is not available then: /ip:port-index
243 sort_host_length
= snprintf(sort_host
, sizeof(sort_host
),
245 list
[host_index
].hostname
,
246 (uint32_t)list
[host_index
].port
,
249 if (size_t(sort_host_length
) >= sizeof(sort_host
) or sort_host_length
< 0)
251 return memcached_set_error(*ptr
, MEMCACHED_MEMORY_ALLOCATION_FAILURE
, MEMCACHED_AT
,
252 memcached_literal_param("snprintf(sizeof(sort_host))"));
257 fprintf(stdout
, "update_continuum: key is %s\n", sort_host
);
260 if (is_ketama_weighted
)
262 for (uint32_t x
= 0; x
< pointer_per_hash
; x
++)
264 uint32_t value
= ketama_server_hash(sort_host
, (size_t)sort_host_length
, x
);
265 ptr
->ketama
.continuum
[continuum_index
].index
= host_index
;
266 ptr
->ketama
.continuum
[continuum_index
++].value
= value
;
271 uint32_t value
= hashkit_digest(&ptr
->hashkit
, sort_host
, (size_t)sort_host_length
);
272 ptr
->ketama
.continuum
[continuum_index
].index
= host_index
;
273 ptr
->ketama
.continuum
[continuum_index
++].value
= value
;
279 for (uint32_t pointer_index
= 1;
280 pointer_index
<= pointer_per_server
/ pointer_per_hash
;
283 char sort_host
[MEMCACHED_NI_MAXHOST
+1 +MEMCACHED_NI_MAXSERV
+1 +MEMCACHED_NI_MAXSERV
]= "";
284 int sort_host_length
;
286 if (list
[host_index
].port
== MEMCACHED_DEFAULT_PORT
)
288 sort_host_length
= snprintf(sort_host
, sizeof(sort_host
),
290 list
[host_index
].hostname
,
295 sort_host_length
= snprintf(sort_host
, sizeof(sort_host
),
297 list
[host_index
].hostname
,
298 (uint32_t)list
[host_index
].port
,
302 if (size_t(sort_host_length
) >= sizeof(sort_host
) or sort_host_length
< 0)
304 return memcached_set_error(*ptr
, MEMCACHED_MEMORY_ALLOCATION_FAILURE
, MEMCACHED_AT
,
305 memcached_literal_param("snprintf(sizeof(sort_host)))"));
308 if (is_ketama_weighted
)
310 for (uint32_t x
= 0; x
< pointer_per_hash
; x
++)
312 uint32_t value
= ketama_server_hash(sort_host
, (size_t)sort_host_length
, x
);
313 ptr
->ketama
.continuum
[continuum_index
].index
= host_index
;
314 ptr
->ketama
.continuum
[continuum_index
++].value
= value
;
319 uint32_t value
= hashkit_digest(&ptr
->hashkit
, sort_host
, (size_t)sort_host_length
);
320 ptr
->ketama
.continuum
[continuum_index
].index
= host_index
;
321 ptr
->ketama
.continuum
[continuum_index
++].value
= value
;
326 pointer_counter
+= pointer_per_server
;
329 WATCHPOINT_ASSERT(ptr
);
330 WATCHPOINT_ASSERT(ptr
->ketama
.continuum
);
331 WATCHPOINT_ASSERT(memcached_server_count(ptr
) * MEMCACHED_POINTS_PER_SERVER
<= MEMCACHED_CONTINUUM_SIZE
);
332 ptr
->ketama
.continuum_points_counter
= pointer_counter
;
333 qsort(ptr
->ketama
.continuum
, ptr
->ketama
.continuum_points_counter
, sizeof(memcached_continuum_item_st
), continuum_item_cmp
);
337 for (uint32_t pointer_index
= 0; memcached_server_count(ptr
) && pointer_index
< ((live_servers
* MEMCACHED_POINTS_PER_SERVER
) - 1); pointer_index
++)
339 WATCHPOINT_ASSERT(ptr
->ketama
.continuum
[pointer_index
].value
<= ptr
->ketama
.continuum
[pointer_index
+ 1].value
);
343 return MEMCACHED_SUCCESS
;
346 static memcached_return_t
server_add(memcached_st
*ptr
,
347 const memcached_string_t
& hostname
,
350 memcached_connection_t type
)
352 assert_msg(ptr
, "Programmer mistake, somehow server_add() was passed a NULL memcached_st");
354 memcached_instance_st
*new_host_list
= libmemcached_xrealloc(ptr
, memcached_instance_list(ptr
), (ptr
->number_of_hosts
+ 1), memcached_instance_st
);
356 if (new_host_list
== NULL
)
358 return memcached_set_error(*ptr
, MEMCACHED_MEMORY_ALLOCATION_FAILURE
, MEMCACHED_AT
);
361 memcached_instance_set(ptr
, new_host_list
);
363 /* TODO: Check return type */
364 memcached_server_write_instance_st instance
= memcached_server_instance_fetch(ptr
, memcached_server_count(ptr
));
366 if (__instance_create_with(ptr
, instance
, hostname
, port
, weight
, type
) == NULL
)
368 return memcached_set_error(*ptr
, MEMCACHED_MEMORY_ALLOCATION_FAILURE
, MEMCACHED_AT
);
373 ptr
->ketama
.weighted
= true;
376 ptr
->number_of_hosts
++;
378 // @note we place the count in the bottom of the server list
379 instance
= memcached_server_instance_fetch(ptr
, 0);
380 memcached_instance_set_count(instance
, memcached_server_count(ptr
));
382 return run_distribution(ptr
);
386 memcached_return_t
memcached_server_push(memcached_st
*ptr
, const memcached_server_list_st list
)
390 return MEMCACHED_SUCCESS
;
393 uint32_t count
= memcached_server_list_count(list
);
395 memcached_instance_st
*new_host_list
= libmemcached_xrealloc(ptr
, memcached_instance_list(ptr
), (count
+ memcached_server_count(ptr
)), memcached_instance_st
);
397 if (new_host_list
== NULL
)
399 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
402 memcached_instance_set(ptr
, new_host_list
);
404 for (uint32_t x
= 0; x
< count
; x
++)
406 memcached_server_write_instance_st instance
;
408 WATCHPOINT_ASSERT(list
[x
].hostname
[0] != 0);
410 // We have extended the array, and now we will find it, and use it.
411 instance
= memcached_server_instance_fetch(ptr
, memcached_server_count(ptr
));
412 WATCHPOINT_ASSERT(instance
);
414 memcached_string_t hostname
= { memcached_string_make_from_cstr(list
[x
].hostname
) };
415 if (__instance_create_with(ptr
, instance
,
417 list
[x
].port
, list
[x
].weight
, list
[x
].type
) == NULL
)
419 return memcached_set_error(*ptr
, MEMCACHED_MEMORY_ALLOCATION_FAILURE
, MEMCACHED_AT
);
422 if (list
[x
].weight
> 1)
424 ptr
->ketama
.weighted
= true;
427 ptr
->number_of_hosts
++;
430 // Provides backwards compatibility with server list.
432 memcached_server_write_instance_st instance
;
433 instance
= memcached_server_instance_fetch(ptr
, 0);
434 instance
->number_of_hosts
= memcached_server_count(ptr
);
437 return run_distribution(ptr
);
440 memcached_return_t
memcached_instance_push(memcached_st
*ptr
, const struct memcached_instance_st
* list
, uint32_t number_of_hosts
)
444 return MEMCACHED_SUCCESS
;
447 memcached_instance_st
* new_host_list
= libmemcached_xrealloc(ptr
, memcached_instance_list(ptr
), (number_of_hosts
+memcached_server_count(ptr
)), memcached_instance_st
);
449 if (new_host_list
== NULL
)
451 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
454 memcached_instance_set(ptr
, new_host_list
);
456 for (uint32_t x
= 0; x
< number_of_hosts
; x
++)
458 memcached_server_write_instance_st instance
;
460 WATCHPOINT_ASSERT(list
[x
].hostname
[0] != 0);
462 // We have extended the array, and now we will find it, and use it.
463 instance
= memcached_server_instance_fetch(ptr
, memcached_server_count(ptr
));
464 WATCHPOINT_ASSERT(instance
);
466 memcached_string_t hostname
= { memcached_string_make_from_cstr(list
[x
].hostname
) };
467 if (__instance_create_with(ptr
, instance
,
469 list
[x
].port
, list
[x
].weight
, list
[x
].type
) == NULL
)
471 return memcached_set_error(*ptr
, MEMCACHED_MEMORY_ALLOCATION_FAILURE
, MEMCACHED_AT
);
474 if (list
[x
].weight
> 1)
476 ptr
->ketama
.weighted
= true;
479 ptr
->number_of_hosts
++;
482 // Provides backwards compatibility with server list.
484 memcached_server_write_instance_st instance
;
485 instance
= memcached_server_instance_fetch(ptr
, 0);
486 instance
->number_of_hosts
= memcached_server_count(ptr
);
489 return run_distribution(ptr
);
492 memcached_return_t
memcached_server_add_unix_socket(memcached_st
*ptr
,
493 const char *filename
)
495 return memcached_server_add_unix_socket_with_weight(ptr
, filename
, 0);
498 memcached_return_t
memcached_server_add_unix_socket_with_weight(memcached_st
*ptr
,
499 const char *filename
,
504 return MEMCACHED_FAILURE
;
507 memcached_string_t _filename
= { memcached_string_make_from_cstr(filename
) };
508 if (memcached_is_valid_servername(_filename
) == false)
510 memcached_set_error(*ptr
, MEMCACHED_INVALID_ARGUMENTS
, MEMCACHED_AT
, memcached_literal_param("Invalid filename for socket provided"));
513 return server_add(ptr
, _filename
, 0, weight
, MEMCACHED_CONNECTION_UNIX_SOCKET
);
516 memcached_return_t
memcached_server_add_udp(memcached_st
*ptr
,
517 const char *hostname
,
520 return memcached_server_add_udp_with_weight(ptr
, hostname
, port
, 0);
523 memcached_return_t
memcached_server_add_udp_with_weight(memcached_st
*ptr
,
530 return MEMCACHED_INVALID_ARGUMENTS
;
533 return memcached_set_error(*ptr
, MEMCACHED_DEPRECATED
, MEMCACHED_AT
);
536 memcached_return_t
memcached_server_add(memcached_st
*ptr
,
537 const char *hostname
,
540 return memcached_server_add_with_weight(ptr
, hostname
, port
, 0);
543 memcached_return_t
memcached_server_add_with_weight(memcached_st
*ptr
,
544 const char *hostname
,
550 return MEMCACHED_INVALID_ARGUMENTS
;
555 port
= MEMCACHED_DEFAULT_PORT
;
558 size_t hostname_length
= hostname
? strlen(hostname
) : 0;
559 if (hostname_length
== 0)
561 hostname
= "localhost";
562 hostname_length
= memcached_literal_param_size("localhost");
565 memcached_string_t _hostname
= { hostname
, hostname_length
};
567 if (memcached_is_valid_servername(_hostname
) == false)
569 return memcached_set_error(*ptr
, MEMCACHED_INVALID_ARGUMENTS
, MEMCACHED_AT
, memcached_literal_param("Invalid hostname provided"));
572 return server_add(ptr
, _hostname
, port
, weight
, _hostname
.c_str
[0] == '/' ? MEMCACHED_CONNECTION_UNIX_SOCKET
: MEMCACHED_CONNECTION_TCP
);
575 memcached_return_t
memcached_server_add_parsed(memcached_st
*ptr
,
576 const char *hostname
,
577 size_t hostname_length
,
581 char buffer
[NI_MAXHOST
];
583 memcpy(buffer
, hostname
, hostname_length
);
584 buffer
[hostname_length
]= 0;
586 memcached_string_t _hostname
= { buffer
, hostname_length
};
588 return server_add(ptr
, _hostname
,
591 MEMCACHED_CONNECTION_TCP
);