1 /**
2 * collectd - src/memcached.c, based on src/hddtemp.c
3 * Copyright (C) 2007 Antony Dovgal
4 * Copyright (C) 2007-2012 Florian Forster
5 * Copyright (C) 2009 Doug MacEachern
6 * Copyright (C) 2009 Franck Lombardi
7 * Copyright (C) 2012 Nicolas Szalay
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2 of the License, or (at your
12 * option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 *
23 * Authors:
24 * Antony Dovgal <tony at daylessday dot org>
25 * Florian octo Forster <octo at collectd.org>
26 * Doug MacEachern <dougm at hyperic.com>
27 * Franck Lombardi
28 * Nicolas Szalay
29 **/
31 #include "collectd.h"
33 #include "common.h"
34 #include "plugin.h"
36 #include <netdb.h>
37 #include <sys/un.h>
38 #include <netinet/in.h>
39 #include <netinet/tcp.h>
41 #define MEMCACHED_DEF_HOST "127.0.0.1"
42 #define MEMCACHED_DEF_PORT "11211"
44 struct memcached_s
45 {
46 char *name;
47 char *socket;
48 char *host;
49 char *port;
50 };
51 typedef struct memcached_s memcached_t;
53 static _Bool memcached_have_instances = 0;
55 static void memcached_free (void *arg)
56 {
57 memcached_t *st = arg;
58 if (st == NULL)
59 return;
61 sfree (st->name);
62 sfree (st->socket);
63 sfree (st->host);
64 sfree (st->port);
65 sfree (st);
66 }
68 static int memcached_connect_unix (memcached_t *st)
69 {
70 struct sockaddr_un serv_addr = { 0 };
71 int fd;
73 serv_addr.sun_family = AF_UNIX;
74 sstrncpy (serv_addr.sun_path, st->socket,
75 sizeof (serv_addr.sun_path));
77 /* create our socket descriptor */
78 fd = socket (AF_UNIX, SOCK_STREAM, 0);
79 if (fd < 0)
80 {
81 char errbuf[1024];
82 ERROR ("memcached plugin: memcached_connect_unix: socket(2) failed: %s",
83 sstrerror (errno, errbuf, sizeof (errbuf)));
84 return (-1);
85 }
87 /* connect to the memcached daemon */
88 int status = connect (fd, (struct sockaddr *)&serv_addr, sizeof(serv_addr));
89 if (status != 0)
90 {
91 shutdown (fd, SHUT_RDWR);
92 close (fd);
93 fd = -1;
94 }
96 return (fd);
97 } /* int memcached_connect_unix */
99 static int memcached_connect_inet (memcached_t *st)
100 {
101 const char *host;
102 const char *port;
104 struct addrinfo *ai_list;
105 int status;
106 int fd = -1;
108 host = (st->host != NULL) ? st->host : MEMCACHED_DEF_HOST;
109 port = (st->port != NULL) ? st->port : MEMCACHED_DEF_PORT;
111 struct addrinfo ai_hints = {
112 .ai_family = AF_UNSPEC,
113 .ai_flags = AI_ADDRCONFIG,
114 .ai_socktype = SOCK_STREAM
115 };
117 status = getaddrinfo (host, port, &ai_hints, &ai_list);
118 if (status != 0)
119 {
120 char errbuf[1024];
121 ERROR ("memcached plugin: memcached_connect_inet: "
122 "getaddrinfo(%s,%s) failed: %s",
123 host, port,
124 (status == EAI_SYSTEM)
125 ? sstrerror (errno, errbuf, sizeof (errbuf))
126 : gai_strerror (status));
127 return (-1);
128 }
130 for (struct addrinfo *ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
131 {
132 /* create our socket descriptor */
133 fd = socket (ai_ptr->ai_family, ai_ptr->ai_socktype, ai_ptr->ai_protocol);
134 if (fd < 0)
135 {
136 char errbuf[1024];
137 WARNING ("memcached plugin: memcached_connect_inet: "
138 "socket(2) failed: %s",
139 sstrerror (errno, errbuf, sizeof (errbuf)));
140 continue;
141 }
143 /* connect to the memcached daemon */
144 status = (int) connect (fd, ai_ptr->ai_addr, ai_ptr->ai_addrlen);
145 if (status != 0)
146 {
147 shutdown (fd, SHUT_RDWR);
148 close (fd);
149 fd = -1;
150 continue;
151 }
153 /* A socket could be opened and connecting succeeded. We're done. */
154 break;
155 }
157 freeaddrinfo (ai_list);
158 return (fd);
159 } /* int memcached_connect_inet */
161 static int memcached_connect (memcached_t *st)
162 {
163 if (st->socket != NULL)
164 return (memcached_connect_unix (st));
165 else
166 return (memcached_connect_inet (st));
167 }
169 static int memcached_query_daemon (char *buffer, size_t buffer_size, memcached_t *st)
170 {
171 int fd, status;
172 size_t buffer_fill;
174 fd = memcached_connect (st);
175 if (fd < 0) {
176 ERROR ("memcached plugin: Instance \"%s\" could not connect to daemon.",
177 st->name);
178 return -1;
179 }
181 status = (int) swrite (fd, "stats\r\n", strlen ("stats\r\n"));
182 if (status != 0)
183 {
184 char errbuf[1024];
185 ERROR ("memcached plugin: write(2) failed: %s",
186 sstrerror (errno, errbuf, sizeof (errbuf)));
187 shutdown(fd, SHUT_RDWR);
188 close (fd);
189 return (-1);
190 }
192 /* receive data from the memcached daemon */
193 memset (buffer, 0, buffer_size);
195 buffer_fill = 0;
196 while ((status = (int) recv (fd, buffer + buffer_fill,
197 buffer_size - buffer_fill, /* flags = */ 0)) != 0)
198 {
199 char const end_token[5] = {'E', 'N', 'D', '\r', '\n'};
200 if (status < 0)
201 {
202 char errbuf[1024];
204 if ((errno == EAGAIN) || (errno == EINTR))
205 continue;
207 ERROR ("memcached: Error reading from socket: %s",
208 sstrerror (errno, errbuf, sizeof (errbuf)));
209 shutdown(fd, SHUT_RDWR);
210 close (fd);
211 return (-1);
212 }
214 buffer_fill += (size_t) status;
215 if (buffer_fill > buffer_size)
216 {
217 buffer_fill = buffer_size;
218 WARNING ("memcached plugin: Message was truncated.");
219 break;
220 }
222 /* If buffer ends in end_token, we have all the data. */
223 if (memcmp (buffer + buffer_fill - sizeof (end_token),
224 end_token, sizeof (end_token)) == 0)
225 break;
226 } /* while (recv) */
228 status = 0;
229 if (buffer_fill == 0)
230 {
231 WARNING ("memcached plugin: No data returned by memcached.");
232 status = -1;
233 }
235 shutdown(fd, SHUT_RDWR);
236 close(fd);
237 return (status);
238 } /* int memcached_query_daemon */
240 static void memcached_init_vl (value_list_t *vl, memcached_t const *st)
241 {
242 char const *host = st->host;
244 /* Keep default hostname, if:
245 * - Legacy mode is used.
246 * - "Socket" option is given (doc: "Host option is ignored").
247 * - "Host" option is not provided.
248 * - "Host" option is set to "localhost" or "127.0.0.1". */
249 if ((strcmp (st->name, "__legacy__") != 0)
250 && (st->socket == NULL)
251 && (st->host != NULL)
252 && (strcmp ("127.0.0.1", st->host) != 0)
253 && (strcmp ("localhost", st->host) != 0))
254 sstrncpy (vl->host, host, sizeof (vl->host));
256 sstrncpy (vl->plugin, "memcached", sizeof (vl->plugin));
257 if (strcmp (st->name, "__legacy__") != 0)
258 sstrncpy (vl->plugin_instance, st->name, sizeof (vl->plugin_instance));
259 }
261 static void submit_derive (const char *type, const char *type_inst,
262 derive_t value, memcached_t *st)
263 {
264 value_list_t vl = VALUE_LIST_INIT;
266 memcached_init_vl (&vl, st);
267 vl.values = &(value_t) { .derive = value };
268 vl.values_len = 1;
269 sstrncpy (vl.type, type, sizeof (vl.type));
270 if (type_inst != NULL)
271 sstrncpy (vl.type_instance, type_inst, sizeof (vl.type_instance));
273 plugin_dispatch_values (&vl);
274 }
276 static void submit_derive2 (const char *type, const char *type_inst,
277 derive_t value0, derive_t value1, memcached_t *st)
278 {
279 value_list_t vl = VALUE_LIST_INIT;
280 value_t values[] = {
281 { .derive = value0 },
282 { .derive = value1 },
283 };
285 memcached_init_vl (&vl, st);
286 vl.values = values;
287 vl.values_len = STATIC_ARRAY_SIZE (values);
288 sstrncpy (vl.type, type, sizeof (vl.type));
289 if (type_inst != NULL)
290 sstrncpy (vl.type_instance, type_inst, sizeof (vl.type_instance));
292 plugin_dispatch_values (&vl);
293 }
295 static void submit_gauge (const char *type, const char *type_inst,
296 gauge_t value, memcached_t *st)
297 {
298 value_list_t vl = VALUE_LIST_INIT;
300 memcached_init_vl (&vl, st);
301 vl.values = &(value_t) { .gauge = value };
302 vl.values_len = 1;
303 sstrncpy (vl.type, type, sizeof (vl.type));
304 if (type_inst != NULL)
305 sstrncpy (vl.type_instance, type_inst, sizeof (vl.type_instance));
307 plugin_dispatch_values (&vl);
308 }
310 static void submit_gauge2 (const char *type, const char *type_inst,
311 gauge_t value0, gauge_t value1, memcached_t *st)
312 {
313 value_list_t vl = VALUE_LIST_INIT;
314 value_t values[] = {
315 { .gauge = value0 },
316 { .gauge = value1 },
317 };
319 memcached_init_vl (&vl, st);
320 vl.values = values;
321 vl.values_len = STATIC_ARRAY_SIZE (values);
322 sstrncpy (vl.type, type, sizeof (vl.type));
323 if (type_inst != NULL)
324 sstrncpy (vl.type_instance, type_inst, sizeof (vl.type_instance));
326 plugin_dispatch_values (&vl);
327 }
329 static int memcached_read (user_data_t *user_data)
330 {
331 char buf[4096];
332 char *fields[3];
333 char *ptr;
334 char *line;
335 char *saveptr;
336 int fields_num;
338 gauge_t bytes_used = NAN;
339 gauge_t bytes_total = NAN;
340 gauge_t hits = NAN;
341 gauge_t gets = NAN;
342 gauge_t incr_hits = NAN;
343 derive_t incr = 0;
344 gauge_t decr_hits = NAN;
345 derive_t decr = 0;
346 derive_t rusage_user = 0;
347 derive_t rusage_syst = 0;
348 derive_t octets_rx = 0;
349 derive_t octets_tx = 0;
351 memcached_t *st;
352 st = user_data->data;
354 /* get data from daemon */
355 if (memcached_query_daemon (buf, sizeof (buf), st) < 0) {
356 return -1;
357 }
359 #define FIELD_IS(cnst) \
360 (((sizeof(cnst) - 1) == name_len) && (strcmp (cnst, fields[1]) == 0))
362 ptr = buf;
363 saveptr = NULL;
364 while ((line = strtok_r (ptr, "\n\r", &saveptr)) != NULL)
365 {
366 int name_len;
368 ptr = NULL;
370 fields_num = strsplit(line, fields, 3);
371 if (fields_num != 3)
372 continue;
374 name_len = strlen(fields[1]);
375 if (name_len == 0)
376 continue;
378 /*
379 * For an explanation on these fields please refer to
380 * <https://github.com/memcached/memcached/blob/master/doc/protocol.txt>
381 */
383 /*
384 * CPU time consumed by the memcached process
385 */
386 if (FIELD_IS ("rusage_user"))
387 {
388 rusage_user = atoll (fields[2]);
389 }
390 else if (FIELD_IS ("rusage_system"))
391 {
392 rusage_syst = atoll(fields[2]);
393 }
395 /*
396 * Number of threads of this instance
397 */
398 else if (FIELD_IS ("threads"))
399 {
400 submit_gauge2 ("ps_count", NULL, NAN, atof (fields[2]), st);
401 }
403 /*
404 * Number of items stored
405 */
406 else if (FIELD_IS ("curr_items"))
407 {
408 submit_gauge ("memcached_items", "current", atof (fields[2]), st);
409 }
411 /*
412 * Number of bytes used and available (total - used)
413 */
414 else if (FIELD_IS ("bytes"))
415 {
416 bytes_used = atof (fields[2]);
417 }
418 else if (FIELD_IS ("limit_maxbytes"))
419 {
420 bytes_total = atof(fields[2]);
421 }
423 /*
424 * Connections
425 */
426 else if (FIELD_IS ("curr_connections"))
427 {
428 submit_gauge ("memcached_connections", "current", atof (fields[2]), st);
429 }
430 else if (FIELD_IS ("listen_disabled_num"))
431 {
432 submit_derive ("connections", "listen_disabled", atof (fields[2]), st);
433 }
435 /*
436 * Commands
437 */
438 else if ((name_len > 4) && (strncmp (fields[1], "cmd_", 4) == 0))
439 {
440 const char *name = fields[1] + 4;
441 submit_derive ("memcached_command", name, atoll (fields[2]), st);
442 if (strcmp (name, "get") == 0)
443 gets = atof (fields[2]);
444 }
446 /*
447 * Increment/Decrement
448 */
449 else if (FIELD_IS("incr_misses"))
450 {
451 derive_t incr_count = atoll (fields[2]);
452 submit_derive ("memcached_ops", "incr_misses", incr_count, st);
453 incr += incr_count;
454 }
455 else if (FIELD_IS ("incr_hits"))
456 {
457 derive_t incr_count = atoll (fields[2]);
458 submit_derive ("memcached_ops", "incr_hits", incr_count, st);
459 incr_hits = atof (fields[2]);
460 incr += incr_count;
461 }
462 else if (FIELD_IS ("decr_misses"))
463 {
464 derive_t decr_count = atoll (fields[2]);
465 submit_derive ("memcached_ops", "decr_misses", decr_count, st);
466 decr += decr_count;
467 }
468 else if (FIELD_IS ("decr_hits"))
469 {
470 derive_t decr_count = atoll (fields[2]);
471 submit_derive ("memcached_ops", "decr_hits", decr_count, st);
472 decr_hits = atof (fields[2]);
473 decr += decr_count;
474 }
476 /*
477 * Operations on the cache, i. e. cache hits, cache misses and evictions of items
478 */
479 else if (FIELD_IS ("get_hits"))
480 {
481 submit_derive ("memcached_ops", "hits", atoll (fields[2]), st);
482 hits = atof (fields[2]);
483 }
484 else if (FIELD_IS ("get_misses"))
485 {
486 submit_derive ("memcached_ops", "misses", atoll (fields[2]), st);
487 }
488 else if (FIELD_IS ("evictions"))
489 {
490 submit_derive ("memcached_ops", "evictions", atoll (fields[2]), st);
491 }
493 /*
494 * Network traffic
495 */
496 else if (FIELD_IS ("bytes_read"))
497 {
498 octets_rx = atoll (fields[2]);
499 }
500 else if (FIELD_IS ("bytes_written"))
501 {
502 octets_tx = atoll (fields[2]);
503 }
504 } /* while ((line = strtok_r (ptr, "\n\r", &saveptr)) != NULL) */
506 if (!isnan (bytes_used) && !isnan (bytes_total) && (bytes_used <= bytes_total))
507 submit_gauge2 ("df", "cache", bytes_used, bytes_total - bytes_used, st);
509 if ((rusage_user != 0) || (rusage_syst != 0))
510 submit_derive2 ("ps_cputime", NULL, rusage_user, rusage_syst, st);
512 if ((octets_rx != 0) || (octets_tx != 0))
513 submit_derive2 ("memcached_octets", NULL, octets_rx, octets_tx, st);
515 if (!isnan (gets) && !isnan (hits))
516 {
517 gauge_t rate = NAN;
519 if (gets != 0.0)
520 rate = 100.0 * hits / gets;
522 submit_gauge ("percent", "hitratio", rate, st);
523 }
525 if (!isnan (incr_hits) && incr != 0)
526 {
527 gauge_t incr_rate = 100.0 * incr_hits / incr;
528 submit_gauge ("percent", "incr_hitratio", incr_rate, st);
529 submit_derive ("memcached_ops", "incr", incr, st);
530 }
532 if (!isnan (decr_hits) && decr != 0)
533 {
534 gauge_t decr_rate = 100.0 * decr_hits / decr;
535 submit_gauge ("percent", "decr_hitratio", decr_rate, st);
536 submit_derive ("memcached_ops", "decr", decr, st);
537 }
539 return 0;
540 } /* int memcached_read */
542 static int memcached_add_read_callback (memcached_t *st)
543 {
544 char callback_name[3*DATA_MAX_NAME_LEN];
545 int status;
547 assert (st->name != NULL);
548 ssnprintf (callback_name, sizeof (callback_name), "memcached/%s", st->name);
550 status = plugin_register_complex_read (/* group = */ "memcached",
551 /* name = */ callback_name,
552 /* callback = */ memcached_read,
553 /* interval = */ 0,
554 &(user_data_t) {
555 .data = st,
556 .free_func = memcached_free,
557 });
559 return (status);
560 } /* int memcached_add_read_callback */
562 /* Configuration handling functiions
563 * <Plugin memcached>
564 * <Instance "instance_name">
565 * Host foo.zomg.com
566 * Port "1234"
567 * </Instance>
568 * </Plugin>
569 */
570 static int config_add_instance(oconfig_item_t *ci)
571 {
572 memcached_t *st;
573 int status = 0;
575 /* Disable automatic generation of default instance in the init callback. */
576 memcached_have_instances = 1;
578 st = calloc (1, sizeof (*st));
579 if (st == NULL)
580 {
581 ERROR ("memcached plugin: calloc failed.");
582 return (-1);
583 }
585 st->name = NULL;
586 st->socket = NULL;
587 st->host = NULL;
588 st->port = NULL;
590 if (strcasecmp (ci->key, "Plugin") == 0) /* default instance */
591 st->name = sstrdup ("__legacy__");
592 else /* <Instance /> block */
593 status = cf_util_get_string (ci, &st->name);
594 if (status != 0)
595 {
596 sfree (st);
597 return (status);
598 }
599 assert (st->name != NULL);
601 for (int i = 0; i < ci->children_num; i++)
602 {
603 oconfig_item_t *child = ci->children + i;
605 if (strcasecmp ("Socket", child->key) == 0)
606 status = cf_util_get_string (child, &st->socket);
607 else if (strcasecmp ("Host", child->key) == 0)
608 status = cf_util_get_string (child, &st->host);
609 else if (strcasecmp ("Port", child->key) == 0)
610 status = cf_util_get_service (child, &st->port);
611 else
612 {
613 WARNING ("memcached plugin: Option `%s' not allowed here.",
614 child->key);
615 status = -1;
616 }
618 if (status != 0)
619 break;
620 }
622 if (status == 0)
623 status = memcached_add_read_callback (st);
625 if (status != 0)
626 {
627 memcached_free(st);
628 return (-1);
629 }
631 return (0);
632 }
634 static int memcached_config (oconfig_item_t *ci)
635 {
636 int status = 0;
637 _Bool have_instance_block = 0;
639 for (int i = 0; i < ci->children_num; i++)
640 {
641 oconfig_item_t *child = ci->children + i;
643 if (strcasecmp ("Instance", child->key) == 0)
644 {
645 config_add_instance (child);
646 have_instance_block = 1;
647 }
648 else if (!have_instance_block)
649 {
650 /* Non-instance option: Assume legacy configuration (without <Instance />
651 * blocks) and call config_add_instance() with the <Plugin /> block. */
652 return (config_add_instance (ci));
653 }
654 else
655 WARNING ("memcached plugin: The configuration option "
656 "\"%s\" is not allowed here. Did you "
657 "forget to add an <Instance /> block "
658 "around the configuration?",
659 child->key);
660 } /* for (ci->children) */
662 return (status);
663 }
665 static int memcached_init (void)
666 {
667 memcached_t *st;
668 int status;
670 if (memcached_have_instances)
671 return (0);
673 /* No instances were configured, lets start a default instance. */
674 st = calloc (1, sizeof (*st));
675 if (st == NULL)
676 return (ENOMEM);
677 st->name = sstrdup ("__legacy__");
678 st->socket = NULL;
679 st->host = NULL;
680 st->port = NULL;
682 status = memcached_add_read_callback (st);
683 if (status == 0)
684 memcached_have_instances = 1;
685 else
686 memcached_free (st);
688 return (status);
689 } /* int memcached_init */
691 void module_register (void)
692 {
693 plugin_register_complex_config ("memcached", memcached_config);
694 plugin_register_init ("memcached", memcached_init);
695 }