2 * Copyright (C) 2006-2010 Brian Aker
5 * Use and distribution licensed under the BSD license. See
6 * the COPYING file in the parent directory for full text.
15 /* Protoypes (static) */
16 static memcached_return_t
server_add(memcached_st
*ptr
, const char *hostname
,
19 memcached_connection_t type
);
20 static memcached_return_t
update_continuum(memcached_st
*ptr
);
22 static int compare_servers(const void *p1
, const void *p2
)
25 memcached_server_instance_st a
= (memcached_server_instance_st
)p1
;
26 memcached_server_instance_st b
= (memcached_server_instance_st
)p2
;
28 return_value
= strcmp(a
->hostname
, b
->hostname
);
30 if (return_value
== 0)
32 return_value
= (int) (a
->port
- b
->port
);
38 static void sort_hosts(memcached_st
*ptr
)
40 if (memcached_server_count(ptr
))
42 memcached_server_write_instance_st instance
;
44 qsort(memcached_server_list(ptr
), memcached_server_count(ptr
), sizeof(memcached_server_st
), compare_servers
);
45 instance
= memcached_server_instance_fetch(ptr
, 0);
46 instance
->number_of_hosts
= memcached_server_count(ptr
);
51 memcached_return_t
run_distribution(memcached_st
*ptr
)
53 if (ptr
->flags
.use_sort_hosts
)
56 switch (ptr
->distribution
)
58 case MEMCACHED_DISTRIBUTION_CONSISTENT
:
59 case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA
:
60 case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY
:
61 return update_continuum(ptr
);
62 case MEMCACHED_DISTRIBUTION_MODULA
:
64 case MEMCACHED_DISTRIBUTION_RANDOM
:
65 srandom((uint32_t) time(NULL
));
67 case MEMCACHED_DISTRIBUTION_CONSISTENT_MAX
:
69 WATCHPOINT_ASSERT(0); /* We have added a distribution without extending the logic */
72 return MEMCACHED_SUCCESS
;
75 static uint32_t ketama_server_hash(const char *key
, size_t key_length
, uint32_t alignment
)
77 unsigned char results
[16];
79 libhashkit_md5_signature((unsigned char*)key
, key_length
, results
);
81 return ((uint32_t) (results
[3 + alignment
* 4] & 0xFF) << 24)
82 | ((uint32_t) (results
[2 + alignment
* 4] & 0xFF) << 16)
83 | ((uint32_t) (results
[1 + alignment
* 4] & 0xFF) << 8)
84 | (results
[0 + alignment
* 4] & 0xFF);
87 static int continuum_item_cmp(const void *t1
, const void *t2
)
89 memcached_continuum_item_st
*ct1
= (memcached_continuum_item_st
*)t1
;
90 memcached_continuum_item_st
*ct2
= (memcached_continuum_item_st
*)t2
;
92 /* Why 153? Hmmm... */
93 WATCHPOINT_ASSERT(ct1
->value
!= 153);
94 if (ct1
->value
== ct2
->value
)
96 else if (ct1
->value
> ct2
->value
)
102 static memcached_return_t
update_continuum(memcached_st
*ptr
)
105 uint32_t continuum_index
= 0;
107 memcached_server_st
*list
;
108 uint32_t pointer_index
;
109 uint32_t pointer_counter
= 0;
110 uint32_t pointer_per_server
= MEMCACHED_POINTS_PER_SERVER
;
111 uint32_t pointer_per_hash
= 1;
112 uint64_t total_weight
= 0;
113 uint64_t is_ketama_weighted
= 0;
114 uint64_t is_auto_ejecting
= 0;
115 uint32_t points_per_server
= 0;
116 uint32_t live_servers
= 0;
119 if (gettimeofday(&now
, NULL
) != 0)
121 ptr
->cached_errno
= errno
;
122 return MEMCACHED_ERRNO
;
125 list
= memcached_server_list(ptr
);
127 /* count live servers (those without a retry delay set) */
128 is_auto_ejecting
= _is_auto_eject_host(ptr
);
129 if (is_auto_ejecting
)
132 ptr
->next_distribution_rebuild
= 0;
133 for (host_index
= 0; host_index
< memcached_server_count(ptr
); ++host_index
)
135 if (list
[host_index
].next_retry
<= now
.tv_sec
)
139 if (ptr
->next_distribution_rebuild
== 0 || list
[host_index
].next_retry
< ptr
->next_distribution_rebuild
)
140 ptr
->next_distribution_rebuild
= list
[host_index
].next_retry
;
146 live_servers
= memcached_server_count(ptr
);
149 is_ketama_weighted
= memcached_behavior_get(ptr
, MEMCACHED_BEHAVIOR_KETAMA_WEIGHTED
);
150 points_per_server
= (uint32_t) (is_ketama_weighted
? MEMCACHED_POINTS_PER_SERVER_KETAMA
: MEMCACHED_POINTS_PER_SERVER
);
152 if (live_servers
== 0)
153 return MEMCACHED_SUCCESS
;
155 if (live_servers
> ptr
->continuum_count
)
157 memcached_continuum_item_st
*new_ptr
;
159 new_ptr
= libmemcached_realloc(ptr
, ptr
->continuum
,
160 sizeof(memcached_continuum_item_st
) * (live_servers
+ MEMCACHED_CONTINUUM_ADDITION
) * points_per_server
);
163 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
165 ptr
->continuum
= new_ptr
;
166 ptr
->continuum_count
= live_servers
+ MEMCACHED_CONTINUUM_ADDITION
;
169 if (is_ketama_weighted
)
171 for (host_index
= 0; host_index
< memcached_server_count(ptr
); ++host_index
)
173 if (list
[host_index
].weight
== 0)
175 list
[host_index
].weight
= 1;
177 if (! is_auto_ejecting
|| list
[host_index
].next_retry
<= now
.tv_sec
)
178 total_weight
+= list
[host_index
].weight
;
182 for (host_index
= 0; host_index
< memcached_server_count(ptr
); ++host_index
)
184 if (is_auto_ejecting
&& list
[host_index
].next_retry
> now
.tv_sec
)
187 if (is_ketama_weighted
)
189 float pct
= (float)list
[host_index
].weight
/ (float)total_weight
;
190 pointer_per_server
= (uint32_t) ((floorf((float) (pct
* MEMCACHED_POINTS_PER_SERVER_KETAMA
/ 4 * (float)live_servers
+ 0.0000000001))) * 4);
193 printf("ketama_weighted:%s|%d|%llu|%u\n",
194 list
[host_index
].hostname
,
195 list
[host_index
].port
,
196 (unsigned long long)list
[host_index
].weight
,
202 if (ptr
->distribution
== MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY
)
204 for (pointer_index
= 0;
205 pointer_index
< pointer_per_server
/ pointer_per_hash
;
208 char sort_host
[MEMCACHED_MAX_HOST_SORT_LENGTH
]= "";
209 int sort_host_length
;
211 // Spymemcached ketema key format is: hostname/ip:port-index
212 // If hostname is not available then: /ip:port-index
213 sort_host_length
= snprintf(sort_host
, MEMCACHED_MAX_HOST_SORT_LENGTH
,
215 list
[host_index
].hostname
,
216 (uint32_t)list
[host_index
].port
,
219 if (sort_host_length
>= MEMCACHED_MAX_HOST_SORT_LENGTH
|| sort_host_length
< 0)
221 return MEMCACHED_FAILURE
;
224 printf("update_continuum: key is %s\n", sort_host
);
227 WATCHPOINT_ASSERT(sort_host_length
);
229 if (is_ketama_weighted
)
231 for (uint32_t x
= 0; x
< pointer_per_hash
; x
++)
233 value
= ketama_server_hash(sort_host
, (size_t)sort_host_length
, x
);
234 ptr
->continuum
[continuum_index
].index
= host_index
;
235 ptr
->continuum
[continuum_index
++].value
= value
;
240 value
= hashkit_digest(&ptr
->distribution_hashkit
, sort_host
, (size_t)sort_host_length
);
241 ptr
->continuum
[continuum_index
].index
= host_index
;
242 ptr
->continuum
[continuum_index
++].value
= value
;
248 for (pointer_index
= 1;
249 pointer_index
<= pointer_per_server
/ pointer_per_hash
;
252 char sort_host
[MEMCACHED_MAX_HOST_SORT_LENGTH
]= "";
253 int sort_host_length
;
255 if (list
[host_index
].port
== MEMCACHED_DEFAULT_PORT
)
257 sort_host_length
= snprintf(sort_host
, MEMCACHED_MAX_HOST_SORT_LENGTH
,
259 list
[host_index
].hostname
,
264 sort_host_length
= snprintf(sort_host
, MEMCACHED_MAX_HOST_SORT_LENGTH
,
266 list
[host_index
].hostname
,
267 (uint32_t)list
[host_index
].port
,
271 if (sort_host_length
>= MEMCACHED_MAX_HOST_SORT_LENGTH
|| sort_host_length
< 0)
273 return MEMCACHED_FAILURE
;
276 WATCHPOINT_ASSERT(sort_host_length
);
278 if (is_ketama_weighted
)
280 for (uint32_t x
= 0; x
< pointer_per_hash
; x
++)
282 value
= ketama_server_hash(sort_host
, (size_t)sort_host_length
, x
);
283 ptr
->continuum
[continuum_index
].index
= host_index
;
284 ptr
->continuum
[continuum_index
++].value
= value
;
289 value
= hashkit_digest(&ptr
->distribution_hashkit
, sort_host
, (size_t)sort_host_length
);
290 ptr
->continuum
[continuum_index
].index
= host_index
;
291 ptr
->continuum
[continuum_index
++].value
= value
;
296 pointer_counter
+= pointer_per_server
;
299 WATCHPOINT_ASSERT(ptr
);
300 WATCHPOINT_ASSERT(ptr
->continuum
);
301 WATCHPOINT_ASSERT(memcached_server_count(ptr
) * MEMCACHED_POINTS_PER_SERVER
<= MEMCACHED_CONTINUUM_SIZE
);
302 ptr
->continuum_points_counter
= pointer_counter
;
303 qsort(ptr
->continuum
, ptr
->continuum_points_counter
, sizeof(memcached_continuum_item_st
), continuum_item_cmp
);
306 for (pointer_index
= 0; memcached_server_count(ptr
) && pointer_index
< ((live_servers
* MEMCACHED_POINTS_PER_SERVER
) - 1); pointer_index
++)
308 WATCHPOINT_ASSERT(ptr
->continuum
[pointer_index
].value
<= ptr
->continuum
[pointer_index
+ 1].value
);
312 return MEMCACHED_SUCCESS
;
316 memcached_return_t
memcached_server_push(memcached_st
*ptr
, const memcached_server_list_st list
)
319 memcached_server_st
*new_host_list
;
322 return MEMCACHED_SUCCESS
;
324 count
= memcached_server_list_count(list
);
325 new_host_list
= libmemcached_realloc(ptr
, memcached_server_list(ptr
),
326 sizeof(memcached_server_st
) * (count
+ memcached_server_count(ptr
)));
329 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
331 memcached_server_list_set(ptr
, new_host_list
);
333 for (uint32_t x
= 0; x
< count
; x
++)
335 memcached_server_write_instance_st instance
;
337 if ((ptr
->flags
.use_udp
&& list
[x
].type
!= MEMCACHED_CONNECTION_UDP
)
338 || ((list
[x
].type
== MEMCACHED_CONNECTION_UDP
)
339 && ! (ptr
->flags
.use_udp
)) )
340 return MEMCACHED_INVALID_HOST_PROTOCOL
;
342 WATCHPOINT_ASSERT(list
[x
].hostname
[0] != 0);
344 instance
= memcached_server_instance_fetch(ptr
, memcached_server_count(ptr
));
346 /* TODO check return type */
347 (void)memcached_server_create_with(ptr
, instance
, list
[x
].hostname
,
348 list
[x
].port
, list
[x
].weight
, list
[x
].type
);
349 ptr
->number_of_hosts
++;
352 // Provides backwards compatibility with server list.
354 memcached_server_write_instance_st instance
;
355 instance
= memcached_server_instance_fetch(ptr
, 0);
356 instance
->number_of_hosts
= memcached_server_count(ptr
);
359 return run_distribution(ptr
);
362 memcached_return_t
memcached_server_add_unix_socket(memcached_st
*ptr
,
363 const char *filename
)
365 return memcached_server_add_unix_socket_with_weight(ptr
, filename
, 0);
368 memcached_return_t
memcached_server_add_unix_socket_with_weight(memcached_st
*ptr
,
369 const char *filename
,
373 return MEMCACHED_FAILURE
;
375 return server_add(ptr
, filename
, 0, weight
, MEMCACHED_CONNECTION_UNIX_SOCKET
);
378 memcached_return_t
memcached_server_add_udp(memcached_st
*ptr
,
379 const char *hostname
,
382 return memcached_server_add_udp_with_weight(ptr
, hostname
, port
, 0);
385 memcached_return_t
memcached_server_add_udp_with_weight(memcached_st
*ptr
,
386 const char *hostname
,
391 port
= MEMCACHED_DEFAULT_PORT
;
394 hostname
= "localhost";
396 return server_add(ptr
, hostname
, port
, weight
, MEMCACHED_CONNECTION_UDP
);
399 memcached_return_t
memcached_server_add(memcached_st
*ptr
,
400 const char *hostname
,
403 return memcached_server_add_with_weight(ptr
, hostname
, port
, 0);
406 memcached_return_t
memcached_server_add_with_weight(memcached_st
*ptr
,
407 const char *hostname
,
412 port
= MEMCACHED_DEFAULT_PORT
;
415 hostname
= "localhost";
417 return server_add(ptr
, hostname
, port
, weight
, MEMCACHED_CONNECTION_TCP
);
420 static memcached_return_t
server_add(memcached_st
*ptr
, const char *hostname
,
423 memcached_connection_t type
)
425 memcached_server_st
*new_host_list
;
426 memcached_server_write_instance_st instance
;
428 if ( (ptr
->flags
.use_udp
&& type
!= MEMCACHED_CONNECTION_UDP
)
429 || ( (type
== MEMCACHED_CONNECTION_UDP
) && (! ptr
->flags
.use_udp
) ) )
430 return MEMCACHED_INVALID_HOST_PROTOCOL
;
432 new_host_list
= libmemcached_realloc(ptr
, memcached_server_list(ptr
),
433 sizeof(memcached_server_st
) * (ptr
->number_of_hosts
+ 1));
435 if (new_host_list
== NULL
)
436 return MEMCACHED_MEMORY_ALLOCATION_FAILURE
;
438 memcached_server_list_set(ptr
, new_host_list
);
440 /* TODO: Check return type */
441 instance
= memcached_server_instance_fetch(ptr
, memcached_server_count(ptr
));
442 (void)memcached_server_create_with(ptr
, instance
, hostname
, port
, weight
, type
);
443 ptr
->number_of_hosts
++;
445 instance
= memcached_server_instance_fetch(ptr
, 0);
446 memcached_servers_set_count(instance
, memcached_server_count(ptr
));
448 return run_distribution(ptr
);