6a54fc0aea4cde2bbe41102969a6b9204e345600
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_t **queries;
106 size_t queries_num;
108 char *host;
109 char *port;
110 char *database;
111 char *user;
112 char *password;
114 char *sslmode;
116 char *krbsrvname;
118 char *service;
119 } c_psql_database_t;
121 static char *def_queries[] = {
122 "backends",
123 "transactions",
124 "queries",
125 "query_plans",
126 "table_states",
127 "disk_io",
128 "disk_usage"
129 };
130 static int def_queries_num = STATIC_ARRAY_SIZE (def_queries);
132 static udb_query_t **queries = NULL;
133 static size_t queries_num = 0;
135 static c_psql_database_t *databases = NULL;
136 static int databases_num = 0;
138 static c_psql_database_t *c_psql_database_new (const char *name)
139 {
140 c_psql_database_t *db;
142 ++databases_num;
143 if (NULL == (databases = (c_psql_database_t *)realloc (databases,
144 databases_num * sizeof (*databases)))) {
145 log_err ("Out of memory.");
146 exit (5);
147 }
149 db = databases + (databases_num - 1);
151 db->conn = NULL;
153 C_COMPLAIN_INIT (&db->conn_complaint);
155 db->proto_version = 0;
156 db->server_version = 0;
158 db->max_params_num = 0;
160 db->queries = NULL;
161 db->queries_num = 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 (c_psql_database_t *db)
178 {
179 PQfinish (db->conn);
180 db->conn = NULL;
182 sfree (db->queries);
183 db->queries_num = 0;
185 sfree (db->database);
186 sfree (db->host);
187 sfree (db->port);
188 sfree (db->user);
189 sfree (db->password);
191 sfree (db->sslmode);
193 sfree (db->krbsrvname);
195 sfree (db->service);
196 return;
197 } /* c_psql_database_delete */
199 static int c_psql_connect (c_psql_database_t *db)
200 {
201 char conninfo[4096];
202 char *buf = conninfo;
203 int buf_len = sizeof (conninfo);
204 int status;
206 if (! db)
207 return -1;
209 status = ssnprintf (buf, buf_len, "dbname = '%s'", db->database);
210 if (0 < status) {
211 buf += status;
212 buf_len -= status;
213 }
215 C_PSQL_PAR_APPEND (buf, buf_len, "host", db->host);
216 C_PSQL_PAR_APPEND (buf, buf_len, "port", db->port);
217 C_PSQL_PAR_APPEND (buf, buf_len, "user", db->user);
218 C_PSQL_PAR_APPEND (buf, buf_len, "password", db->password);
219 C_PSQL_PAR_APPEND (buf, buf_len, "sslmode", db->sslmode);
220 C_PSQL_PAR_APPEND (buf, buf_len, "krbsrvname", db->krbsrvname);
221 C_PSQL_PAR_APPEND (buf, buf_len, "service", db->service);
223 db->conn = PQconnectdb (conninfo);
224 db->proto_version = PQprotocolVersion (db->conn);
225 return 0;
226 } /* c_psql_connect */
228 static int c_psql_check_connection (c_psql_database_t *db)
229 {
230 _Bool init = 0;
232 if (! db->conn) {
233 init = 1;
235 /* trigger c_release() */
236 if (0 == db->conn_complaint.interval)
237 db->conn_complaint.interval = 1;
239 c_psql_connect (db);
240 }
242 /* "ping" */
243 PQclear (PQexec (db->conn, "SELECT 42;"));
245 if (CONNECTION_OK != PQstatus (db->conn)) {
246 PQreset (db->conn);
248 /* trigger c_release() */
249 if (0 == db->conn_complaint.interval)
250 db->conn_complaint.interval = 1;
252 if (CONNECTION_OK != PQstatus (db->conn)) {
253 c_complain (LOG_ERR, &db->conn_complaint,
254 "Failed to connect to database %s: %s",
255 db->database, PQerrorMessage (db->conn));
256 return -1;
257 }
259 db->proto_version = PQprotocolVersion (db->conn);
260 }
262 db->server_version = PQserverVersion (db->conn);
264 if (c_would_release (&db->conn_complaint)) {
265 char *server_host;
266 int server_version;
268 server_host = PQhost (db->conn);
269 server_version = PQserverVersion (db->conn);
271 c_do_release (LOG_INFO, &db->conn_complaint,
272 "Successfully %sconnected to database %s (user %s) "
273 "at server %s%s%s (server version: %d.%d.%d, "
274 "protocol version: %d, pid: %d)", init ? "" : "re",
275 PQdb (db->conn), PQuser (db->conn),
276 C_PSQL_SOCKET3 (server_host, PQport (db->conn)),
277 C_PSQL_SERVER_VERSION3 (server_version),
278 db->proto_version, PQbackendPID (db->conn));
280 if (3 > db->proto_version)
281 log_warn ("Protocol version %d does not support parameters.",
282 db->proto_version);
283 }
284 return 0;
285 } /* c_psql_check_connection */
287 static PGresult *c_psql_exec_query_noparams (c_psql_database_t *db,
288 udb_query_t *q)
289 {
290 return PQexec (db->conn, udb_query_get_statement (q));
291 } /* c_psql_exec_query_noparams */
293 static PGresult *c_psql_exec_query_params (c_psql_database_t *db,
294 udb_query_t *q, c_psql_user_data_t *data)
295 {
296 char *params[db->max_params_num];
297 char interval[64];
298 int i;
300 if ((data == NULL) || (data->params_num == 0))
301 return (c_psql_exec_query_noparams (db, q));
303 assert (db->max_params_num >= data->params_num);
305 for (i = 0; i < data->params_num; ++i) {
306 switch (data->params[i]) {
307 case C_PSQL_PARAM_HOST:
308 params[i] = C_PSQL_IS_UNIX_DOMAIN_SOCKET (db->host)
309 ? "localhost" : db->host;
310 break;
311 case C_PSQL_PARAM_DB:
312 params[i] = db->database;
313 break;
314 case C_PSQL_PARAM_USER:
315 params[i] = db->user;
316 break;
317 case C_PSQL_PARAM_INTERVAL:
318 ssnprintf (interval, sizeof (interval), "%i", interval_g);
319 params[i] = interval;
320 break;
321 default:
322 assert (0);
323 }
324 }
326 return PQexecParams (db->conn, udb_query_get_statement (q),
327 data->params_num, NULL,
328 (const char *const *) params,
329 NULL, NULL, /* return text data */ 0);
330 } /* c_psql_exec_query_params */
332 static int c_psql_exec_query (c_psql_database_t *db, udb_query_t *q)
333 {
334 PGresult *res;
336 c_psql_user_data_t *data;
338 const char *host;
340 char **column_names;
341 char **column_values;
342 int column_num;
344 int rows_num;
345 int status;
346 int row, col;
348 /* The user data may hold parameter information, but may be NULL. */
349 data = udb_query_get_user_data (q);
351 /* Versions up to `3' don't know how to handle parameters. */
352 if (3 <= db->proto_version)
353 res = c_psql_exec_query_params (db, q, data);
354 else if ((NULL == data) || (0 == data->params_num))
355 res = c_psql_exec_query_noparams (db, q);
356 else {
357 log_err ("Connection to database \"%s\" does not support parameters "
358 "(protocol version %d) - cannot execute query \"%s\".",
359 db->database, db->proto_version,
360 udb_query_get_name (q));
361 return -1;
362 }
364 column_names = NULL;
365 column_values = NULL;
367 #define BAIL_OUT(status) \
368 sfree (column_names); \
369 sfree (column_values); \
370 PQclear (res); \
371 return status
373 if (PGRES_TUPLES_OK != PQresultStatus (res)) {
374 log_err ("Failed to execute SQL query: %s",
375 PQerrorMessage (db->conn));
376 log_info ("SQL query was: %s",
377 udb_query_get_statement (q));
378 BAIL_OUT (-1);
379 }
381 rows_num = PQntuples (res);
382 if (1 > rows_num) {
383 BAIL_OUT (0);
384 }
386 column_num = PQnfields (res);
387 column_names = (char **) calloc (column_num, sizeof (char *));
388 if (NULL == column_names) {
389 log_err ("calloc failed.");
390 BAIL_OUT (-1);
391 }
393 column_values = (char **) calloc (column_num, sizeof (char *));
394 if (NULL == column_values) {
395 log_err ("calloc failed.");
396 BAIL_OUT (-1);
397 }
399 for (col = 0; col < column_num; ++col) {
400 /* Pointers returned by `PQfname' are freed by `PQclear' via
401 * `BAIL_OUT'. */
402 column_names[col] = PQfname (res, col);
403 if (NULL == column_names[col]) {
404 log_err ("Failed to resolve name of column %i.", col);
405 BAIL_OUT (-1);
406 }
407 }
409 if (C_PSQL_IS_UNIX_DOMAIN_SOCKET (db->host)
410 || (0 == strcmp (db->host, "localhost")))
411 host = hostname_g;
412 else
413 host = db->host;
415 status = udb_query_prepare_result (q, host, "postgresql",
416 db->database, column_names, (size_t) column_num);
417 if (0 != status) {
418 log_err ("udb_query_prepare_result failed with status %i.",
419 status);
420 BAIL_OUT (-1);
421 }
423 for (row = 0; row < rows_num; ++row) {
424 for (col = 0; col < column_num; ++col) {
425 /* Pointers returned by `PQgetvalue' are freed by `PQclear' via
426 * `BAIL_OUT'. */
427 column_values[col] = PQgetvalue (res, row, col);
428 if (NULL == column_values[col]) {
429 log_err ("Failed to get value at (row = %i, col = %i).",
430 row, col);
431 break;
432 }
433 }
435 /* check for an error */
436 if (col < column_num)
437 continue;
439 status = udb_query_handle_result (q, column_values);
440 if (status != 0) {
441 log_err ("udb_query_handle_result failed with status %i.",
442 status);
443 }
444 } /* for (row = 0; row < rows_num; ++row) */
446 BAIL_OUT (0);
447 #undef BAIL_OUT
448 } /* c_psql_exec_query */
450 static int c_psql_read (void)
451 {
452 int success = 0;
453 int i;
455 for (i = 0; i < databases_num; ++i) {
456 c_psql_database_t *db = databases + i;
458 int j;
460 assert (NULL != db->database);
462 if (0 != c_psql_check_connection (db))
463 continue;
465 for (j = 0; j < db->queries_num; ++j)
466 {
467 udb_query_t *q;
469 q = db->queries[j];
471 if ((0 != db->server_version)
472 && (udb_query_check_version (q, db->server_version) <= 0))
473 continue;
475 c_psql_exec_query (db, q);
476 }
478 ++success;
479 }
481 if (! success)
482 return -1;
483 return 0;
484 } /* c_psql_read */
486 static int c_psql_shutdown (void)
487 {
488 int i;
490 if ((NULL == databases) || (0 == databases_num))
491 return 0;
493 plugin_unregister_read ("postgresql");
494 plugin_unregister_shutdown ("postgresql");
496 for (i = 0; i < databases_num; ++i)
497 c_psql_database_delete (databases + i);
499 sfree (databases);
500 databases_num = 0;
502 udb_query_free (queries, queries_num);
503 queries = NULL;
504 queries_num = 0;
506 return 0;
507 } /* c_psql_shutdown */
509 static int c_psql_init (void)
510 {
511 if ((NULL == databases) || (0 == databases_num))
512 return 0;
514 plugin_register_read ("postgresql", c_psql_read);
515 plugin_register_shutdown ("postgresql", c_psql_shutdown);
516 return 0;
517 } /* c_psql_init */
519 static int config_set_s (char *name, char **var, const oconfig_item_t *ci)
520 {
521 if ((0 != ci->children_num) || (1 != ci->values_num)
522 || (OCONFIG_TYPE_STRING != ci->values[0].type)) {
523 log_err ("%s expects a single string argument.", name);
524 return 1;
525 }
527 sfree (*var);
528 *var = sstrdup (ci->values[0].value.string);
529 return 0;
530 } /* config_set_s */
532 static int config_query_param_add (udb_query_t *q, oconfig_item_t *ci)
533 {
534 c_psql_user_data_t *data;
535 const char *param_str;
537 c_psql_param_t *tmp;
539 data = udb_query_get_user_data (q);
540 if (NULL == data) {
541 data = (c_psql_user_data_t *) smalloc (sizeof (*data));
542 if (NULL == data) {
543 log_err ("Out of memory.");
544 return -1;
545 }
546 memset (data, 0, sizeof (*data));
547 data->params = NULL;
548 }
550 tmp = (c_psql_param_t *) realloc (data->params,
551 (data->params_num + 1) * sizeof (c_psql_param_t));
552 if (NULL == tmp) {
553 log_err ("Out of memory.");
554 return -1;
555 }
556 data->params = tmp;
558 param_str = ci->values[0].value.string;
559 if (0 == strcasecmp (param_str, "hostname"))
560 data->params[data->params_num] = C_PSQL_PARAM_HOST;
561 else if (0 == strcasecmp (param_str, "database"))
562 data->params[data->params_num] = C_PSQL_PARAM_DB;
563 else if (0 == strcasecmp (param_str, "username"))
564 data->params[data->params_num] = C_PSQL_PARAM_USER;
565 else if (0 == strcasecmp (param_str, "interval"))
566 data->params[data->params_num] = C_PSQL_PARAM_INTERVAL;
567 else {
568 log_err ("Invalid parameter \"%s\".", param_str);
569 return 1;
570 }
572 data->params_num++;
573 udb_query_set_user_data (q, data);
575 return (0);
576 } /* config_query_param_add */
578 static int config_query_callback (udb_query_t *q, oconfig_item_t *ci)
579 {
580 if (0 == strcasecmp ("Param", ci->key))
581 return config_query_param_add (q, ci);
583 log_err ("Option not allowed within a Query block: `%s'", ci->key);
585 return (-1);
586 } /* config_query_callback */
588 static int c_psql_config_database (oconfig_item_t *ci)
589 {
590 c_psql_database_t *db;
592 int i;
594 if ((1 != ci->values_num)
595 || (OCONFIG_TYPE_STRING != ci->values[0].type)) {
596 log_err ("<Database> expects a single string argument.");
597 return 1;
598 }
600 db = c_psql_database_new (ci->values[0].value.string);
602 for (i = 0; i < ci->children_num; ++i) {
603 oconfig_item_t *c = ci->children + i;
605 if (0 == strcasecmp (c->key, "Host"))
606 config_set_s ("Host", &db->host, c);
607 else if (0 == strcasecmp (c->key, "Port"))
608 config_set_s ("Port", &db->port, c);
609 else if (0 == strcasecmp (c->key, "User"))
610 config_set_s ("User", &db->user, c);
611 else if (0 == strcasecmp (c->key, "Password"))
612 config_set_s ("Password", &db->password, c);
613 else if (0 == strcasecmp (c->key, "SSLMode"))
614 config_set_s ("SSLMode", &db->sslmode, c);
615 else if (0 == strcasecmp (c->key, "KRBSrvName"))
616 config_set_s ("KRBSrvName", &db->krbsrvname, c);
617 else if (0 == strcasecmp (c->key, "Service"))
618 config_set_s ("Service", &db->service, c);
619 else if (0 == strcasecmp (c->key, "Query"))
620 udb_query_pick_from_list (c, queries, queries_num,
621 &db->queries, &db->queries_num);
622 else
623 log_warn ("Ignoring unknown config key \"%s\".", c->key);
624 }
626 /* If no `Query' options were given, add the default queries.. */
627 if (db->queries_num == 0)
628 {
629 for (i = 0; i < def_queries_num; i++)
630 udb_query_pick_from_list_by_name (def_queries[i],
631 queries, queries_num,
632 &db->queries, &db->queries_num);
633 }
635 for (i = 0; (size_t)i < db->queries_num; ++i) {
636 c_psql_user_data_t *data;
637 data = udb_query_get_user_data (db->queries[i]);
638 if ((data != NULL) && (data->params_num > db->max_params_num))
639 db->max_params_num = data->params_num;
640 }
641 return 0;
642 } /* c_psql_config_database */
644 static int c_psql_config (oconfig_item_t *ci)
645 {
646 static int have_def_config = 0;
648 int i;
650 if (0 == have_def_config) {
651 oconfig_item_t *c;
653 have_def_config = 1;
655 c = oconfig_parse_file (C_PSQL_DEFAULT_CONF);
656 if (NULL == c)
657 log_err ("Failed to read default config ("C_PSQL_DEFAULT_CONF").");
658 else
659 c_psql_config (c);
661 if (NULL == queries)
662 log_err ("Default config ("C_PSQL_DEFAULT_CONF") did not define "
663 "any queries - please check your installation.");
664 }
666 for (i = 0; i < ci->children_num; ++i) {
667 oconfig_item_t *c = ci->children + i;
669 if (0 == strcasecmp (c->key, "Query"))
670 udb_query_create (&queries, &queries_num, c,
671 /* callback = */ config_query_callback,
672 /* legacy mode = */ 1);
673 else if (0 == strcasecmp (c->key, "Database"))
674 c_psql_config_database (c);
675 else
676 log_warn ("Ignoring unknown config key \"%s\".", c->key);
677 }
678 return 0;
679 } /* c_psql_config */
681 void module_register (void)
682 {
683 plugin_register_complex_config ("postgresql", c_psql_config);
684 plugin_register_init ("postgresql", c_psql_init);
685 } /* module_register */
687 /* vim: set sw=4 ts=4 tw=78 noexpandtab : */