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
server_add(memcached_st
*ptr
, const char *hostname
,
47 memcached_connection_t type
);
49 static memcached_return_t
update_continuum(memcached_st
*ptr
);
51 static int compare_servers(const void *p1
, const void *p2
)
54 memcached_server_instance_st a
= (memcached_server_instance_st
)p1
;
55 memcached_server_instance_st b
= (memcached_server_instance_st
)p2
;
57 return_value
= strcmp(a
->hostname
, b
->hostname
);
59 if (return_value
== 0)
61 return_value
= (int) (a
->port
- b
->port
);
67 static void sort_hosts(memcached_st
*ptr
)
69 if (memcached_server_count(ptr
))
71 memcached_server_write_instance_st instance
;
73 qsort(memcached_server_list(ptr
), memcached_server_count(ptr
), sizeof(memcached_server_st
), compare_servers
);
74 instance
= memcached_server_instance_fetch(ptr
, 0);
75 instance
->number_of_hosts
= memcached_server_count(ptr
);
80 memcached_return_t
run_distribution(memcached_st
*ptr
)
82 if (ptr
->flags
.use_sort_hosts
)
87 switch (ptr
->distribution
)
89 case MEMCACHED_DISTRIBUTION_CONSISTENT
:
90 case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA
:
91 case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY
:
92 case MEMCACHED_DISTRIBUTION_CONSISTENT_WEIGHTED
:
93 return update_continuum(ptr
);
95 case MEMCACHED_DISTRIBUTION_VIRTUAL_BUCKET
:
96 case MEMCACHED_DISTRIBUTION_MODULA
:
99 case MEMCACHED_DISTRIBUTION_RANDOM
:
100 srandom((uint32_t) time(NULL
));
103 case MEMCACHED_DISTRIBUTION_CONSISTENT_MAX
:
105 assert_msg(0, "Invalid distribution type passed to run_distribution()");
108 return MEMCACHED_SUCCESS
;
111 static uint32_t ketama_server_hash(const char *key
, size_t key_length
, uint32_t alignment
)
113 unsigned char results
[16];
115 libhashkit_md5_signature((unsigned char*)key
, key_length
, results
);
117 return ((uint32_t) (results
[3 + alignment
* 4] & 0xFF) << 24)
118 | ((uint32_t) (results
[2 + alignment
* 4] & 0xFF) << 16)
119 | ((uint32_t) (results
[1 + alignment
* 4] & 0xFF) << 8)
120 | (results
[0 + alignment
* 4] & 0xFF);
123 static int continuum_item_cmp(const void *t1
, const void *t2
)
125 memcached_continuum_item_st
*ct1
= (memcached_continuum_item_st
*)t1
;
126 memcached_continuum_item_st
*ct2
= (memcached_continuum_item_st
*)t2
;
128 /* Why 153? Hmmm... */
129 WATCHPOINT_ASSERT(ct1
->value
!= 153);
130 if (ct1
->value
== ct2
->value
)
132 else if (ct1
->value
> ct2
->value
)
138 static memcached_return_t
update_continuum(memcached_st
*ptr
)
140 uint32_t continuum_index
= 0;
141 memcached_server_st
*list
;
142 uint32_t pointer_counter
= 0;
143 uint32_t pointer_per_server
= MEMCACHED_POINTS_PER_SERVER
;
144 uint32_t pointer_per_hash
= 1;
145 uint32_t live_servers
= 0;
148 if (gettimeofday(&now
, NULL
))
150 return memcached_set_errno(*ptr
, errno
, MEMCACHED_AT
);
153 list
= memcached_server_list(ptr
);
155 /* count live servers (those without a retry delay set) */
156 bool is_auto_ejecting
= _is_auto_eject_host(ptr
);
157 if (is_auto_ejecting
)
160 ptr
->ketama
.next_distribution_rebuild
= 0;
161 for (uint32_t host_index
= 0; host_index
< memcached_server_count(ptr
); ++host_index
)
163 if (list
[host_index
].next_retry
<= now
.tv_sec
)
169 if (ptr
->ketama
.next_distribution_rebuild
== 0 || list
[host_index
].next_retry
< ptr
->ketama
.next_distribution_rebuild
)
171 ptr
->ketama
.next_distribution_rebuild
= list
[host_index
].next_retry
;
178 live_servers
= memcached_server_count(ptr
);
181 uint64_t is_ketama_weighted
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_KETAMA_WEIGHTED
);
182 uint32_t points_per_server
= (uint32_t) (is_ketama_weighted
? MEMCACHED_POINTS_PER_SERVER_KETAMA
: MEMCACHED_POINTS_PER_SERVER
);
184 if (not live_servers
)
186 return MEMCACHED_SUCCESS
;
189 if (live_servers
> ptr
->ketama
.continuum_count
)
191 memcached_continuum_item_st
*new_ptr
;
193 new_ptr
= static_cast<memcached_continuum_item_st
*>(libmemcached_realloc(ptr
, ptr
->ketama
.continuum
,
194 sizeof(memcached_continuum_item_st
) * (live_servers
+ MEMCACHED_CONTINUUM_ADDITION
) * points_per_server
));
197 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
199 ptr
->ketama
.continuum
= new_ptr
;
200 ptr
->ketama
.continuum_count
= live_servers
+ MEMCACHED_CONTINUUM_ADDITION
;
203 uint64_t total_weight
= 0;
204 if (is_ketama_weighted
)
206 for (uint32_t host_index
= 0; host_index
< memcached_server_count(ptr
); ++host_index
)
208 if (! is_auto_ejecting
|| list
[host_index
].next_retry
<= now
.tv_sec
)
210 total_weight
+= list
[host_index
].weight
;
215 for (uint32_t host_index
= 0; host_index
< memcached_server_count(ptr
); ++host_index
)
217 if (is_auto_ejecting
&& list
[host_index
].next_retry
> now
.tv_sec
)
220 if (is_ketama_weighted
)
222 float pct
= (float)list
[host_index
].weight
/ (float)total_weight
;
223 pointer_per_server
= (uint32_t) ((floorf((float) (pct
* MEMCACHED_POINTS_PER_SERVER_KETAMA
/ 4 * (float)live_servers
+ 0.0000000001))) * 4);
226 printf("ketama_weighted:%s|%d|%llu|%u\n",
227 list
[host_index
].hostname
,
228 list
[host_index
].port
,
229 (unsigned long long)list
[host_index
].weight
,
235 if (ptr
->distribution
== MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY
)
237 for (uint32_t pointer_index
= 0;
238 pointer_index
< pointer_per_server
/ pointer_per_hash
;
241 char sort_host
[MEMCACHED_MAX_HOST_SORT_LENGTH
]= "";
242 int sort_host_length
;
244 // Spymemcached ketema key format is: hostname/ip:port-index
245 // If hostname is not available then: /ip:port-index
246 sort_host_length
= snprintf(sort_host
, MEMCACHED_MAX_HOST_SORT_LENGTH
,
248 list
[host_index
].hostname
,
249 (uint32_t)list
[host_index
].port
,
252 if (sort_host_length
>= MEMCACHED_MAX_HOST_SORT_LENGTH
|| sort_host_length
< 0)
254 return memcached_set_error(*ptr
, MEMCACHED_MEMORY_ALLOCATION_FAILURE
, MEMCACHED_AT
,
255 memcached_literal_param("snprintf(MEMCACHED_DEFAULT_COMMAND_SIZE)"));
258 printf("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_MAX_HOST_SORT_LENGTH
]= "";
284 int sort_host_length
;
286 if (list
[host_index
].port
== MEMCACHED_DEFAULT_PORT
)
288 sort_host_length
= snprintf(sort_host
, MEMCACHED_MAX_HOST_SORT_LENGTH
,
290 list
[host_index
].hostname
,
295 sort_host_length
= snprintf(sort_host
, MEMCACHED_MAX_HOST_SORT_LENGTH
,
297 list
[host_index
].hostname
,
298 (uint32_t)list
[host_index
].port
,
302 if (sort_host_length
>= MEMCACHED_MAX_HOST_SORT_LENGTH
|| sort_host_length
< 0)
304 return memcached_set_error(*ptr
, MEMCACHED_MEMORY_ALLOCATION_FAILURE
, MEMCACHED_AT
,
305 memcached_literal_param("snprintf(MEMCACHED_DEFAULT_COMMAND_SIZE)"));
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
);
336 for (uint32_t pointer_index
= 0; memcached_server_count(ptr
) && pointer_index
< ((live_servers
* MEMCACHED_POINTS_PER_SERVER
) - 1); pointer_index
++)
338 WATCHPOINT_ASSERT(ptr
->ketama
.continuum
[pointer_index
].value
<= ptr
->ketama
.continuum
[pointer_index
+ 1].value
);
342 return MEMCACHED_SUCCESS
;
346 memcached_return_t
memcached_server_push(memcached_st
*ptr
, const memcached_server_list_st list
)
350 return MEMCACHED_SUCCESS
;
353 uint32_t count
= memcached_server_list_count(list
);
355 memcached_server_st
*new_host_list
;
356 new_host_list
= static_cast<memcached_server_st
*>(libmemcached_realloc(ptr
, memcached_server_list(ptr
),
357 sizeof(memcached_server_st
) * (count
+ memcached_server_count(ptr
))));
359 if (not new_host_list
)
360 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
362 memcached_server_list_set(ptr
, new_host_list
);
364 for (uint32_t x
= 0; x
< count
; x
++)
366 memcached_server_write_instance_st instance
;
368 if ((ptr
->flags
.use_udp
&& list
[x
].type
!= MEMCACHED_CONNECTION_UDP
)
369 or ((list
[x
].type
== MEMCACHED_CONNECTION_UDP
) and not (ptr
->flags
.use_udp
)) )
371 return MEMCACHED_INVALID_HOST_PROTOCOL
;
374 WATCHPOINT_ASSERT(list
[x
].hostname
[0] != 0);
376 // We have extended the array, and now we will find it, and use it.
377 instance
= memcached_server_instance_fetch(ptr
, memcached_server_count(ptr
));
378 WATCHPOINT_ASSERT(instance
);
380 if (not __server_create_with(ptr
, instance
, list
[x
].hostname
,
381 list
[x
].port
, list
[x
].weight
, list
[x
].type
))
383 return memcached_set_error(*ptr
, MEMCACHED_MEMORY_ALLOCATION_FAILURE
, MEMCACHED_AT
);
386 if (list
[x
].weight
> 1)
388 ptr
->ketama
.weighted
= true;
391 ptr
->number_of_hosts
++;
394 // Provides backwards compatibility with server list.
396 memcached_server_write_instance_st instance
;
397 instance
= memcached_server_instance_fetch(ptr
, 0);
398 instance
->number_of_hosts
= memcached_server_count(ptr
);
401 return run_distribution(ptr
);
404 memcached_return_t
memcached_server_add_unix_socket(memcached_st
*ptr
,
405 const char *filename
)
407 return memcached_server_add_unix_socket_with_weight(ptr
, filename
, 0);
410 memcached_return_t
memcached_server_add_unix_socket_with_weight(memcached_st
*ptr
,
411 const char *filename
,
415 return MEMCACHED_FAILURE
;
417 return server_add(ptr
, filename
, 0, weight
, MEMCACHED_CONNECTION_UNIX_SOCKET
);
420 memcached_return_t
memcached_server_add_udp(memcached_st
*ptr
,
421 const char *hostname
,
424 return memcached_server_add_udp_with_weight(ptr
, hostname
, port
, 0);
427 memcached_return_t
memcached_server_add_udp_with_weight(memcached_st
*ptr
,
428 const char *hostname
,
433 port
= MEMCACHED_DEFAULT_PORT
;
436 hostname
= "localhost";
438 return server_add(ptr
, hostname
, port
, weight
, MEMCACHED_CONNECTION_UDP
);
441 memcached_return_t
memcached_server_add(memcached_st
*ptr
,
442 const char *hostname
,
445 return memcached_server_add_with_weight(ptr
, hostname
, port
, 0);
448 memcached_return_t
memcached_server_add_with_weight(memcached_st
*ptr
,
449 const char *hostname
,
454 port
= MEMCACHED_DEFAULT_PORT
;
457 hostname
= "localhost";
459 return server_add(ptr
, hostname
, port
, weight
, hostname
[0] == '/' ? MEMCACHED_CONNECTION_UNIX_SOCKET
: MEMCACHED_CONNECTION_TCP
);
462 static memcached_return_t
server_add(memcached_st
*ptr
, const char *hostname
,
465 memcached_connection_t type
)
468 if ( (ptr
->flags
.use_udp
and type
!= MEMCACHED_CONNECTION_UDP
)
469 or ( (type
== MEMCACHED_CONNECTION_UDP
) and (not ptr
->flags
.use_udp
) ) )
471 return MEMCACHED_INVALID_HOST_PROTOCOL
;
474 memcached_server_st
*new_host_list
= static_cast<memcached_server_st
*>(libmemcached_realloc(ptr
, memcached_server_list(ptr
),
475 sizeof(memcached_server_st
) * (ptr
->number_of_hosts
+ 1)));
477 if (not new_host_list
)
478 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
480 memcached_server_list_set(ptr
, new_host_list
);
482 /* TODO: Check return type */
483 memcached_server_write_instance_st instance
= memcached_server_instance_fetch(ptr
, memcached_server_count(ptr
));
485 if (not __server_create_with(ptr
, instance
, hostname
, port
, weight
, type
))
487 return memcached_set_error(*ptr
, MEMCACHED_MEMORY_ALLOCATION_FAILURE
, MEMCACHED_AT
);
492 ptr
->ketama
.weighted
= true;
495 ptr
->number_of_hosts
++;
497 // @note we place the count in the bottom of the server list
498 instance
= memcached_server_instance_fetch(ptr
, 0);
499 memcached_servers_set_count(instance
, memcached_server_count(ptr
));
501 return run_distribution(ptr
);
504 memcached_return_t
memcached_server_add_parsed(memcached_st
*ptr
,
505 const char *hostname
,
506 size_t hostname_length
,
510 char buffer
[NI_MAXHOST
];
512 memcpy(buffer
, hostname
, hostname_length
);
513 buffer
[hostname_length
]= 0;
515 return server_add(ptr
, buffer
,
518 MEMCACHED_CONNECTION_TCP
);