1 /**
2 * collectd - src/postgresql.c
3 * Copyright (C) 2008, 2009 Sebastian Harl
4 * Copyright (C) 2009 Florian Forster
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; only version 2 of the License is applicable.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors:
20 * Sebastian Harl <sh at tokkee.org>
21 * Florian Forster <octo at verplant.org>
22 **/
24 /*
25 * This module collects PostgreSQL database statistics.
26 */
28 #include "collectd.h"
29 #include "common.h"
31 #include "configfile.h"
32 #include "plugin.h"
34 #include "utils_db_query.h"
35 #include "utils_complain.h"
37 #include <pg_config_manual.h>
38 #include <libpq-fe.h>
40 #define log_err(...) ERROR ("postgresql: " __VA_ARGS__)
41 #define log_warn(...) WARNING ("postgresql: " __VA_ARGS__)
42 #define log_info(...) INFO ("postgresql: " __VA_ARGS__)
44 #ifndef C_PSQL_DEFAULT_CONF
45 # define C_PSQL_DEFAULT_CONF PKGDATADIR "/postgresql_default.conf"
46 #endif
48 /* Appends the (parameter, value) pair to the string
49 * pointed to by 'buf' suitable to be used as argument
50 * for PQconnectdb(). If value equals NULL, the pair
51 * is ignored. */
52 #define C_PSQL_PAR_APPEND(buf, buf_len, parameter, value) \
53 if ((0 < (buf_len)) && (NULL != (value)) && ('\0' != *(value))) { \
54 int s = ssnprintf (buf, buf_len, " %s = '%s'", parameter, value); \
55 if (0 < s) { \
56 buf += s; \
57 buf_len -= s; \
58 } \
59 }
61 /* Returns the tuple (major, minor, patchlevel)
62 * for the given version number. */
63 #define C_PSQL_SERVER_VERSION3(server_version) \
64 (server_version) / 10000, \
65 (server_version) / 100 - (int)((server_version) / 10000) * 100, \
66 (server_version) - (int)((server_version) / 100) * 100
68 /* Returns true if the given host specifies a
69 * UNIX domain socket. */
70 #define C_PSQL_IS_UNIX_DOMAIN_SOCKET(host) \
71 ((NULL == (host)) || ('\0' == *(host)) || ('/' == *(host)))
73 /* Returns the tuple (host, delimiter, port) for a
74 * given (host, port) pair. Depending on the value of
75 * 'host' a UNIX domain socket or a TCP socket is
76 * assumed. */
77 #define C_PSQL_SOCKET3(host, port) \
78 ((NULL == (host)) || ('\0' == *(host))) ? DEFAULT_PGSOCKET_DIR : host, \
79 C_PSQL_IS_UNIX_DOMAIN_SOCKET (host) ? "/.s.PGSQL." : ":", \
80 port
82 typedef enum {
83 C_PSQL_PARAM_HOST = 1,
84 C_PSQL_PARAM_DB,
85 C_PSQL_PARAM_USER,
86 C_PSQL_PARAM_INTERVAL,
87 } c_psql_param_t;
89 /* Parameter configuration. Stored as `user data' in the query objects. */
90 typedef struct {
91 c_psql_param_t *params;
92 int params_num;
93 } c_psql_user_data_t;
95 typedef struct {
96 PGconn *conn;
97 c_complain_t conn_complaint;
99 int proto_version;
100 int server_version;
102 int max_params_num;
104 /* user configuration */
105 udb_query_preparation_area_t **q_prep_areas;
106 udb_query_t **queries;
107 size_t queries_num;
109 int interval;
111 char *host;
112 char *port;
113 char *database;
114 char *user;
115 char *password;
117 char *sslmode;
119 char *krbsrvname;
121 char *service;
122 } c_psql_database_t;
124 static char *def_queries[] = {
125 "backends",
126 "transactions",
127 "queries",
128 "query_plans",
129 "table_states",
130 "disk_io",
131 "disk_usage"
132 };
133 static int def_queries_num = STATIC_ARRAY_SIZE (def_queries);
135 static udb_query_t **queries = NULL;
136 static size_t queries_num = 0;
138 static c_psql_database_t *c_psql_database_new (const char *name)
139 {
140 c_psql_database_t *db;
142 db = (c_psql_database_t *)malloc (sizeof (*db));
143 if (NULL == db) {
144 log_err ("Out of memory.");
145 return NULL;
146 }
148 db->conn = NULL;
150 C_COMPLAIN_INIT (&db->conn_complaint);
152 db->proto_version = 0;
153 db->server_version = 0;
155 db->max_params_num = 0;
157 db->q_prep_areas = NULL;
158 db->queries = NULL;
159 db->queries_num = 0;
161 db->interval = 0;
163 db->database = sstrdup (name);
164 db->host = NULL;
165 db->port = NULL;
166 db->user = NULL;
167 db->password = NULL;
169 db->sslmode = NULL;
171 db->krbsrvname = NULL;
173 db->service = NULL;
174 return db;
175 } /* c_psql_database_new */
177 static void c_psql_database_delete (void *data)
178 {
179 size_t i;
181 c_psql_database_t *db = data;
183 PQfinish (db->conn);
184 db->conn = NULL;
186 if (db->q_prep_areas)
187 for (i = 0; i < db->queries_num; ++i)
188 udb_query_delete_preparation_area (db->q_prep_areas[i]);
189 free (db->q_prep_areas);
191 sfree (db->queries);
192 db->queries_num = 0;
194 sfree (db->database);
195 sfree (db->host);
196 sfree (db->port);
197 sfree (db->user);
198 sfree (db->password);
200 sfree (db->sslmode);
202 sfree (db->krbsrvname);
204 sfree (db->service);
205 return;
206 } /* c_psql_database_delete */
208 static int c_psql_connect (c_psql_database_t *db)
209 {
210 char conninfo[4096];
211 char *buf = conninfo;
212 int buf_len = sizeof (conninfo);
213 int status;
215 if (! db)
216 return -1;
218 status = ssnprintf (buf, buf_len, "dbname = '%s'", db->database);
219 if (0 < status) {
220 buf += status;
221 buf_len -= status;
222 }
224 C_PSQL_PAR_APPEND (buf, buf_len, "host", db->host);
225 C_PSQL_PAR_APPEND (buf, buf_len, "port", db->port);
226 C_PSQL_PAR_APPEND (buf, buf_len, "user", db->user);
227 C_PSQL_PAR_APPEND (buf, buf_len, "password", db->password);
228 C_PSQL_PAR_APPEND (buf, buf_len, "sslmode", db->sslmode);
229 C_PSQL_PAR_APPEND (buf, buf_len, "krbsrvname", db->krbsrvname);
230 C_PSQL_PAR_APPEND (buf, buf_len, "service", db->service);
232 db->conn = PQconnectdb (conninfo);
233 db->proto_version = PQprotocolVersion (db->conn);
234 return 0;
235 } /* c_psql_connect */
237 static int c_psql_check_connection (c_psql_database_t *db)
238 {
239 _Bool init = 0;
241 if (! db->conn) {
242 init = 1;
244 /* trigger c_release() */
245 if (0 == db->conn_complaint.interval)
246 db->conn_complaint.interval = 1;
248 c_psql_connect (db);
249 }
251 /* "ping" */
252 PQclear (PQexec (db->conn, "SELECT 42;"));
254 if (CONNECTION_OK != PQstatus (db->conn)) {
255 PQreset (db->conn);
257 /* trigger c_release() */
258 if (0 == db->conn_complaint.interval)
259 db->conn_complaint.interval = 1;
261 if (CONNECTION_OK != PQstatus (db->conn)) {
262 c_complain (LOG_ERR, &db->conn_complaint,
263 "Failed to connect to database %s: %s",
264 db->database, PQerrorMessage (db->conn));
265 return -1;
266 }
268 db->proto_version = PQprotocolVersion (db->conn);
269 }
271 db->server_version = PQserverVersion (db->conn);
273 if (c_would_release (&db->conn_complaint)) {
274 char *server_host;
275 int server_version;
277 server_host = PQhost (db->conn);
278 server_version = PQserverVersion (db->conn);
280 c_do_release (LOG_INFO, &db->conn_complaint,
281 "Successfully %sconnected to database %s (user %s) "
282 "at server %s%s%s (server version: %d.%d.%d, "
283 "protocol version: %d, pid: %d)", init ? "" : "re",
284 PQdb (db->conn), PQuser (db->conn),
285 C_PSQL_SOCKET3 (server_host, PQport (db->conn)),
286 C_PSQL_SERVER_VERSION3 (server_version),
287 db->proto_version, PQbackendPID (db->conn));
289 if (3 > db->proto_version)
290 log_warn ("Protocol version %d does not support parameters.",
291 db->proto_version);
292 }
293 return 0;
294 } /* c_psql_check_connection */
296 static PGresult *c_psql_exec_query_noparams (c_psql_database_t *db,
297 udb_query_t *q)
298 {
299 return PQexec (db->conn, udb_query_get_statement (q));
300 } /* c_psql_exec_query_noparams */
302 static PGresult *c_psql_exec_query_params (c_psql_database_t *db,
303 udb_query_t *q, c_psql_user_data_t *data)
304 {
305 char *params[db->max_params_num];
306 char interval[64];
307 int i;
309 if ((data == NULL) || (data->params_num == 0))
310 return (c_psql_exec_query_noparams (db, q));
312 assert (db->max_params_num >= data->params_num);
314 for (i = 0; i < data->params_num; ++i) {
315 switch (data->params[i]) {
316 case C_PSQL_PARAM_HOST:
317 params[i] = C_PSQL_IS_UNIX_DOMAIN_SOCKET (db->host)
318 ? "localhost" : db->host;
319 break;
320 case C_PSQL_PARAM_DB:
321 params[i] = db->database;
322 break;
323 case C_PSQL_PARAM_USER:
324 params[i] = db->user;
325 break;
326 case C_PSQL_PARAM_INTERVAL:
327 ssnprintf (interval, sizeof (interval), "%i",
328 db->interval > 0 ? db->interval : interval_g);
329 params[i] = interval;
330 break;
331 default:
332 assert (0);
333 }
334 }
336 return PQexecParams (db->conn, udb_query_get_statement (q),
337 data->params_num, NULL,
338 (const char *const *) params,
339 NULL, NULL, /* return text data */ 0);
340 } /* c_psql_exec_query_params */
342 static int c_psql_exec_query (c_psql_database_t *db, udb_query_t *q,
343 udb_query_preparation_area_t *prep_area)
344 {
345 PGresult *res;
347 c_psql_user_data_t *data;
349 const char *host;
351 char **column_names;
352 char **column_values;
353 int column_num;
355 int rows_num;
356 int status;
357 int row, col;
359 /* The user data may hold parameter information, but may be NULL. */
360 data = udb_query_get_user_data (q);
362 /* Versions up to `3' don't know how to handle parameters. */
363 if (3 <= db->proto_version)
364 res = c_psql_exec_query_params (db, q, data);
365 else if ((NULL == data) || (0 == data->params_num))
366 res = c_psql_exec_query_noparams (db, q);
367 else {
368 log_err ("Connection to database \"%s\" does not support parameters "
369 "(protocol version %d) - cannot execute query \"%s\".",
370 db->database, db->proto_version,
371 udb_query_get_name (q));
372 return -1;
373 }
375 column_names = NULL;
376 column_values = NULL;
378 #define BAIL_OUT(status) \
379 sfree (column_names); \
380 sfree (column_values); \
381 PQclear (res); \
382 return status
384 if (PGRES_TUPLES_OK != PQresultStatus (res)) {
385 log_err ("Failed to execute SQL query: %s",
386 PQerrorMessage (db->conn));
387 log_info ("SQL query was: %s",
388 udb_query_get_statement (q));
389 BAIL_OUT (-1);
390 }
392 rows_num = PQntuples (res);
393 if (1 > rows_num) {
394 BAIL_OUT (0);
395 }
397 column_num = PQnfields (res);
398 column_names = (char **) calloc (column_num, sizeof (char *));
399 if (NULL == column_names) {
400 log_err ("calloc failed.");
401 BAIL_OUT (-1);
402 }
404 column_values = (char **) calloc (column_num, sizeof (char *));
405 if (NULL == column_values) {
406 log_err ("calloc failed.");
407 BAIL_OUT (-1);
408 }
410 for (col = 0; col < column_num; ++col) {
411 /* Pointers returned by `PQfname' are freed by `PQclear' via
412 * `BAIL_OUT'. */
413 column_names[col] = PQfname (res, col);
414 if (NULL == column_names[col]) {
415 log_err ("Failed to resolve name of column %i.", col);
416 BAIL_OUT (-1);
417 }
418 }
420 if (C_PSQL_IS_UNIX_DOMAIN_SOCKET (db->host)
421 || (0 == strcmp (db->host, "localhost")))
422 host = hostname_g;
423 else
424 host = db->host;
426 status = udb_query_prepare_result (q, prep_area, host, "postgresql",
427 db->database, column_names, (size_t) column_num);
428 if (0 != status) {
429 log_err ("udb_query_prepare_result failed with status %i.",
430 status);
431 BAIL_OUT (-1);
432 }
434 for (row = 0; row < rows_num; ++row) {
435 for (col = 0; col < column_num; ++col) {
436 /* Pointers returned by `PQgetvalue' are freed by `PQclear' via
437 * `BAIL_OUT'. */
438 column_values[col] = PQgetvalue (res, row, col);
439 if (NULL == column_values[col]) {
440 log_err ("Failed to get value at (row = %i, col = %i).",
441 row, col);
442 break;
443 }
444 }
446 /* check for an error */
447 if (col < column_num)
448 continue;
450 status = udb_query_handle_result (q, prep_area, column_values);
451 if (status != 0) {
452 log_err ("udb_query_handle_result failed with status %i.",
453 status);
454 }
455 } /* for (row = 0; row < rows_num; ++row) */
457 udb_query_finish_result (q, prep_area);
459 BAIL_OUT (0);
460 #undef BAIL_OUT
461 } /* c_psql_exec_query */
463 static int c_psql_read (user_data_t *ud)
464 {
465 c_psql_database_t *db;
466 int i;
468 if ((ud == NULL) || (ud->data == NULL)) {
469 log_err ("c_psql_read: Invalid user data.");
470 return -1;
471 }
473 db = ud->data;
475 assert (NULL != db->database);
477 if (0 != c_psql_check_connection (db))
478 return -1;
480 for (i = 0; i < db->queries_num; ++i)
481 {
482 udb_query_preparation_area_t *prep_area;
483 udb_query_t *q;
485 prep_area = db->q_prep_areas[i];
486 q = db->queries[i];
488 if ((0 != db->server_version)
489 && (udb_query_check_version (q, db->server_version) <= 0))
490 continue;
492 c_psql_exec_query (db, q, prep_area);
493 }
494 return 0;
495 } /* c_psql_read */
497 static int c_psql_shutdown (void)
498 {
499 plugin_unregister_read_group ("postgresql");
501 udb_query_free (queries, queries_num);
502 queries = NULL;
503 queries_num = 0;
505 return 0;
506 } /* c_psql_shutdown */
508 static int config_set_s (char *name, char **var, const oconfig_item_t *ci)
509 {
510 if ((0 != ci->children_num) || (1 != ci->values_num)
511 || (OCONFIG_TYPE_STRING != ci->values[0].type)) {
512 log_err ("%s expects a single string argument.", name);
513 return 1;
514 }
516 sfree (*var);
517 *var = sstrdup (ci->values[0].value.string);
518 return 0;
519 } /* config_set_s */
521 static int config_set_i (char *name, int *var,
522 const oconfig_item_t *ci, int min)
523 {
524 int value;
526 if ((0 != ci->children_num) || (1 != ci->values_num)
527 || (OCONFIG_TYPE_NUMBER != ci->values[0].type)) {
528 log_err ("%s expects a single number argument.", name);
529 return 1;
530 }
532 value = (int)ci->values[0].value.number;
534 if (value < min) {
535 log_err ("%s expects a number greater or equal to %i.", name, min);
536 return 1;
537 }
539 *var = value;
540 return 0;
541 } /* config_set_s */
543 static int config_query_param_add (udb_query_t *q, oconfig_item_t *ci)
544 {
545 c_psql_user_data_t *data;
546 const char *param_str;
548 c_psql_param_t *tmp;
550 data = udb_query_get_user_data (q);
551 if (NULL == data) {
552 data = (c_psql_user_data_t *) smalloc (sizeof (*data));
553 if (NULL == data) {
554 log_err ("Out of memory.");
555 return -1;
556 }
557 memset (data, 0, sizeof (*data));
558 data->params = NULL;
559 }
561 tmp = (c_psql_param_t *) realloc (data->params,
562 (data->params_num + 1) * sizeof (c_psql_param_t));
563 if (NULL == tmp) {
564 log_err ("Out of memory.");
565 return -1;
566 }
567 data->params = tmp;
569 param_str = ci->values[0].value.string;
570 if (0 == strcasecmp (param_str, "hostname"))
571 data->params[data->params_num] = C_PSQL_PARAM_HOST;
572 else if (0 == strcasecmp (param_str, "database"))
573 data->params[data->params_num] = C_PSQL_PARAM_DB;
574 else if (0 == strcasecmp (param_str, "username"))
575 data->params[data->params_num] = C_PSQL_PARAM_USER;
576 else if (0 == strcasecmp (param_str, "interval"))
577 data->params[data->params_num] = C_PSQL_PARAM_INTERVAL;
578 else {
579 log_err ("Invalid parameter \"%s\".", param_str);
580 return 1;
581 }
583 data->params_num++;
584 udb_query_set_user_data (q, data);
586 return (0);
587 } /* config_query_param_add */
589 static int config_query_callback (udb_query_t *q, oconfig_item_t *ci)
590 {
591 if (0 == strcasecmp ("Param", ci->key))
592 return config_query_param_add (q, ci);
594 log_err ("Option not allowed within a Query block: `%s'", ci->key);
596 return (-1);
597 } /* config_query_callback */
599 static int c_psql_config_database (oconfig_item_t *ci)
600 {
601 c_psql_database_t *db;
603 char cb_name[DATA_MAX_NAME_LEN];
604 struct timespec cb_interval;
605 user_data_t ud;
607 int i;
609 if ((1 != ci->values_num)
610 || (OCONFIG_TYPE_STRING != ci->values[0].type)) {
611 log_err ("<Database> expects a single string argument.");
612 return 1;
613 }
615 memset (&ud, 0, sizeof (ud));
617 db = c_psql_database_new (ci->values[0].value.string);
618 if (db == NULL)
619 return -1;
621 for (i = 0; i < ci->children_num; ++i) {
622 oconfig_item_t *c = ci->children + i;
624 if (0 == strcasecmp (c->key, "Host"))
625 config_set_s ("Host", &db->host, c);
626 else if (0 == strcasecmp (c->key, "Port"))
627 config_set_s ("Port", &db->port, c);
628 else if (0 == strcasecmp (c->key, "User"))
629 config_set_s ("User", &db->user, c);
630 else if (0 == strcasecmp (c->key, "Password"))
631 config_set_s ("Password", &db->password, c);
632 else if (0 == strcasecmp (c->key, "SSLMode"))
633 config_set_s ("SSLMode", &db->sslmode, c);
634 else if (0 == strcasecmp (c->key, "KRBSrvName"))
635 config_set_s ("KRBSrvName", &db->krbsrvname, c);
636 else if (0 == strcasecmp (c->key, "Service"))
637 config_set_s ("Service", &db->service, c);
638 else if (0 == strcasecmp (c->key, "Query"))
639 udb_query_pick_from_list (c, queries, queries_num,
640 &db->queries, &db->queries_num);
641 else if (0 == strcasecmp (c->key, "Interval"))
642 config_set_i ("Interval", &db->interval, c, /* min = */ 1);
643 else
644 log_warn ("Ignoring unknown config key \"%s\".", c->key);
645 }
647 /* If no `Query' options were given, add the default queries.. */
648 if (db->queries_num == 0) {
649 for (i = 0; i < def_queries_num; i++)
650 udb_query_pick_from_list_by_name (def_queries[i],
651 queries, queries_num,
652 &db->queries, &db->queries_num);
653 }
655 if (db->queries_num > 0) {
656 db->q_prep_areas = (udb_query_preparation_area_t **) calloc (
657 db->queries_num, sizeof (*db->q_prep_areas));
659 if (db->q_prep_areas == NULL) {
660 log_err ("Out of memory.");
661 c_psql_database_delete (db);
662 return -1;
663 }
664 }
666 for (i = 0; (size_t)i < db->queries_num; ++i) {
667 c_psql_user_data_t *data;
668 data = udb_query_get_user_data (db->queries[i]);
669 if ((data != NULL) && (data->params_num > db->max_params_num))
670 db->max_params_num = data->params_num;
672 db->q_prep_areas[i]
673 = udb_query_allocate_preparation_area (db->queries[i]);
675 if (db->q_prep_areas[i] == NULL) {
676 log_err ("Out of memory.");
677 c_psql_database_delete (db);
678 return -1;
679 }
680 }
682 ud.data = db;
683 ud.free_func = c_psql_database_delete;
685 ssnprintf (cb_name, sizeof (cb_name), "postgresql-%s", db->database);
687 memset (&cb_interval, 0, sizeof (cb_interval));
688 if (db->interval > 0)
689 cb_interval.tv_sec = (time_t)db->interval;
691 plugin_register_complex_read ("postgresql", cb_name, c_psql_read,
692 /* interval = */ &cb_interval, &ud);
693 return 0;
694 } /* c_psql_config_database */
696 static int c_psql_config (oconfig_item_t *ci)
697 {
698 static int have_def_config = 0;
700 int i;
702 if (0 == have_def_config) {
703 oconfig_item_t *c;
705 have_def_config = 1;
707 c = oconfig_parse_file (C_PSQL_DEFAULT_CONF);
708 if (NULL == c)
709 log_err ("Failed to read default config ("C_PSQL_DEFAULT_CONF").");
710 else
711 c_psql_config (c);
713 if (NULL == queries)
714 log_err ("Default config ("C_PSQL_DEFAULT_CONF") did not define "
715 "any queries - please check your installation.");
716 }
718 for (i = 0; i < ci->children_num; ++i) {
719 oconfig_item_t *c = ci->children + i;
721 if (0 == strcasecmp (c->key, "Query"))
722 udb_query_create (&queries, &queries_num, c,
723 /* callback = */ config_query_callback,
724 /* legacy mode = */ 1);
725 else if (0 == strcasecmp (c->key, "Database"))
726 c_psql_config_database (c);
727 else
728 log_warn ("Ignoring unknown config key \"%s\".", c->key);
729 }
730 return 0;
731 } /* c_psql_config */
733 void module_register (void)
734 {
735 plugin_register_complex_config ("postgresql", c_psql_config);
736 plugin_register_shutdown ("postgresql", c_psql_shutdown);
737 } /* module_register */
739 /* vim: set sw=4 ts=4 tw=78 noexpandtab : */