Code

Merge remote-tracking branch 'github/pr/387'
[collectd.git] / src / postgresql.c
index 7bc450eaae51bc20c413c2e36269c4760432d62e..1eaf6bd3877570a56c0e50c045b7e90cc888cda2 100644 (file)
@@ -1,7 +1,7 @@
 /**
  * collectd - src/postgresql.c
- * Copyright (C) 2008, 2009  Sebastian Harl
- * Copyright (C) 2009        Florian Forster
+ * Copyright (C) 2008-2012  Sebastian Harl
+ * Copyright (C) 2009       Florian Forster
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -42,6 +42,7 @@
 #include "configfile.h"
 #include "plugin.h"
 
+#include "utils_cache.h"
 #include "utils_db_query.h"
 #include "utils_complain.h"
 
@@ -55,6 +56,7 @@
 #define log_err(...) ERROR ("postgresql: " __VA_ARGS__)
 #define log_warn(...) WARNING ("postgresql: " __VA_ARGS__)
 #define log_info(...) INFO ("postgresql: " __VA_ARGS__)
+#define log_debug(...) DEBUG ("postgresql: " __VA_ARGS__)
 
 #ifndef C_PSQL_DEFAULT_CONF
 # define C_PSQL_DEFAULT_CONF PKGDATADIR "/postgresql_default.conf"
@@ -99,6 +101,7 @@ typedef enum {
        C_PSQL_PARAM_DB,
        C_PSQL_PARAM_USER,
        C_PSQL_PARAM_INTERVAL,
+       C_PSQL_PARAM_INSTANCE,
 } c_psql_param_t;
 
 /* Parameter configuration. Stored as `user data' in the query objects. */
@@ -110,6 +113,7 @@ typedef struct {
 typedef struct {
        char *name;
        char *statement;
+       _Bool store_rates;
 } c_psql_writer_t;
 
 typedef struct {
@@ -134,17 +138,25 @@ typedef struct {
 
        cdtime_t interval;
 
+       /* writer "caching" settings */
+       cdtime_t commit_interval;
+       cdtime_t next_commit;
+
        char *host;
        char *port;
        char *database;
        char *user;
        char *password;
 
+       char *instance;
+
        char *sslmode;
 
        char *krbsrvname;
 
        char *service;
+
+       int ref_cnt;
 } c_psql_database_t;
 
 static char *def_queries[] = {
@@ -158,22 +170,77 @@ static char *def_queries[] = {
 };
 static int def_queries_num = STATIC_ARRAY_SIZE (def_queries);
 
-static udb_query_t      **queries       = NULL;
-static size_t             queries_num   = 0;
+static c_psql_database_t **databases     = NULL;
+static size_t              databases_num = 0;
+
+static udb_query_t       **queries       = NULL;
+static size_t              queries_num   = 0;
+
+static c_psql_writer_t    *writers       = NULL;
+static size_t              writers_num   = 0;
 
-static c_psql_writer_t   *writers       = NULL;
-static size_t             writers_num   = 0;
+static int c_psql_begin (c_psql_database_t *db)
+{
+       PGresult *r = PQexec (db->conn, "BEGIN");
+
+       int status = 1;
+
+       if (r != NULL) {
+               if (PGRES_COMMAND_OK == PQresultStatus (r)) {
+                       db->next_commit = cdtime() + db->commit_interval;
+                       status = 0;
+               }
+               else
+                       log_warn ("Failed to initiate ('BEGIN') transaction: %s",
+                                       PQerrorMessage (db->conn));
+               PQclear (r);
+       }
+       return status;
+} /* c_psql_begin */
+
+static int c_psql_commit (c_psql_database_t *db)
+{
+       PGresult *r = PQexec (db->conn, "COMMIT");
+
+       int status = 1;
+
+       if (r != NULL) {
+               if (PGRES_COMMAND_OK == PQresultStatus (r)) {
+                       db->next_commit = 0;
+                       log_debug ("Successfully committed transaction.");
+                       status = 0;
+               }
+               else
+                       log_warn ("Failed to commit transaction: %s",
+                                       PQerrorMessage (db->conn));
+               PQclear (r);
+       }
+       return status;
+} /* c_psql_commit */
 
 static c_psql_database_t *c_psql_database_new (const char *name)
 {
-       c_psql_database_t *db;
+       c_psql_database_t **tmp;
+       c_psql_database_t  *db;
 
-       db = (c_psql_database_t *)malloc (sizeof (*db));
+       db = (c_psql_database_t *)malloc (sizeof(*db));
        if (NULL == db) {
                log_err ("Out of memory.");
                return NULL;
        }
 
+       tmp = (c_psql_database_t **)realloc (databases,
+                       (databases_num + 1) * sizeof (*databases));
+       if (NULL == tmp) {
+               log_err ("Out of memory.");
+               sfree (db);
+               return NULL;
+       }
+
+       databases = tmp;
+       databases[databases_num] = db;
+       ++databases_num;
+
        db->conn = NULL;
 
        C_COMPLAIN_INIT (&db->conn_complaint);
@@ -194,17 +261,24 @@ static c_psql_database_t *c_psql_database_new (const char *name)
 
        db->interval   = 0;
 
+       db->commit_interval = 0;
+       db->next_commit     = 0;
+
        db->database   = sstrdup (name);
        db->host       = NULL;
        db->port       = NULL;
        db->user       = NULL;
        db->password   = NULL;
 
+       db->instance   = sstrdup (name);
+
        db->sslmode    = NULL;
 
        db->krbsrvname = NULL;
 
        db->service    = NULL;
+
+       db->ref_cnt    = 0;
        return db;
 } /* c_psql_database_new */
 
@@ -214,6 +288,17 @@ static void c_psql_database_delete (void *data)
 
        c_psql_database_t *db = data;
 
+       --db->ref_cnt;
+       /* readers and writers may access this database */
+       if (db->ref_cnt > 0)
+               return;
+
+       /* wait for the lock to be released by the last writer */
+       pthread_mutex_lock (&db->db_lock);
+
+       if (db->next_commit > 0)
+               c_psql_commit (db);
+
        PQfinish (db->conn);
        db->conn = NULL;
 
@@ -228,6 +313,8 @@ static void c_psql_database_delete (void *data)
        sfree (db->writers);
        db->writers_num = 0;
 
+       pthread_mutex_unlock (&db->db_lock);
+
        pthread_mutex_destroy (&db->db_lock);
 
        sfree (db->database);
@@ -236,11 +323,18 @@ static void c_psql_database_delete (void *data)
        sfree (db->user);
        sfree (db->password);
 
+       sfree (db->instance);
+
        sfree (db->sslmode);
 
        sfree (db->krbsrvname);
 
        sfree (db->service);
+
+       /* don't care about freeing or reordering the 'databases' array
+        * this is done in 'shutdown'; also, don't free the database instance
+        * object just to make sure that in case anybody accesses it before
+        * shutdown won't segfault */
        return;
 } /* c_psql_database_delete */
 
@@ -251,7 +345,7 @@ static int c_psql_connect (c_psql_database_t *db)
        int   buf_len = sizeof (conninfo);
        int   status;
 
-       if (! db)
+       if ((! db) || (! db->database))
                return -1;
 
        status = ssnprintf (buf, buf_len, "dbname = '%s'", db->database);
@@ -287,9 +381,6 @@ static int c_psql_check_connection (c_psql_database_t *db)
                c_psql_connect (db);
        }
 
-       /* "ping" */
-       PQclear (PQexec (db->conn, "SELECT 42;"));
-
        if (CONNECTION_OK != PQstatus (db->conn)) {
                PQreset (db->conn);
 
@@ -299,8 +390,9 @@ static int c_psql_check_connection (c_psql_database_t *db)
 
                if (CONNECTION_OK != PQstatus (db->conn)) {
                        c_complain (LOG_ERR, &db->conn_complaint,
-                                       "Failed to connect to database %s: %s",
-                                       db->database, PQerrorMessage (db->conn));
+                                       "Failed to connect to database %s (%s): %s",
+                                       db->database, db->instance,
+                                       PQerrorMessage (db->conn));
                        return -1;
                }
 
@@ -365,9 +457,13 @@ static PGresult *c_psql_exec_query_params (c_psql_database_t *db,
                        case C_PSQL_PARAM_INTERVAL:
                                ssnprintf (interval, sizeof (interval), "%.3f",
                                                (db->interval > 0)
-                                               ? CDTIME_T_TO_DOUBLE (db->interval) : interval_g);
+                                               ? CDTIME_T_TO_DOUBLE (db->interval)
+                                               : plugin_get_interval ());
                                params[i] = interval;
                                break;
+                       case C_PSQL_PARAM_INSTANCE:
+                               params[i] = db->instance;
+                               break;
                        default:
                                assert (0);
                }
@@ -406,9 +502,10 @@ static int c_psql_exec_query (c_psql_database_t *db, udb_query_t *q,
        else if ((NULL == data) || (0 == data->params_num))
                res = c_psql_exec_query_noparams (db, q);
        else {
-               log_err ("Connection to database \"%s\" does not support parameters "
-                               "(protocol version %d) - cannot execute query \"%s\".",
-                               db->database, db->proto_version,
+               log_err ("Connection to database \"%s\" (%s) does not support "
+                               "parameters (protocol version %d) - "
+                               "cannot execute query \"%s\".",
+                               db->database, db->instance, db->proto_version,
                                udb_query_get_name (q));
                return -1;
        }
@@ -424,6 +521,12 @@ static int c_psql_exec_query (c_psql_database_t *db, udb_query_t *q,
        if (PGRES_TUPLES_OK != PQresultStatus (res)) {
                pthread_mutex_lock (&db->db_lock);
 
+               if ((CONNECTION_OK != PQstatus (db->conn))
+                               && (0 == c_psql_check_connection (db))) {
+                       PQclear (res);
+                       return c_psql_exec_query (db, q, prep_area);
+               }
+
                log_err ("Failed to execute SQL query: %s",
                                PQerrorMessage (db->conn));
                log_info ("SQL query was: %s",
@@ -474,7 +577,7 @@ static int c_psql_exec_query (c_psql_database_t *db, udb_query_t *q,
                host = db->host;
 
        status = udb_query_prepare_result (q, prep_area, host, "postgresql",
-                       db->database, column_names, (size_t) column_num, db->interval);
+                       db->instance, column_names, (size_t) column_num, db->interval);
        if (0 != status) {
                log_err ("udb_query_prepare_result failed with status %i.",
                                status);
@@ -525,6 +628,7 @@ static int c_psql_read (user_data_t *ud)
        db = ud->data;
 
        assert (NULL != db->database);
+       assert (NULL != db->instance);
        assert (NULL != db->queries);
 
        pthread_mutex_lock (&db->db_lock);
@@ -596,23 +700,94 @@ static char *values_name_to_sqlarray (const data_set_t *ds,
        return string;
 } /* values_name_to_sqlarray */
 
+static char *values_type_to_sqlarray (const data_set_t *ds,
+               char *string, size_t string_len, _Bool store_rates)
+{
+       char  *str_ptr;
+       size_t str_len;
+
+       int i;
+
+       str_ptr = string;
+       str_len = string_len;
+
+       for (i = 0; i < ds->ds_num; ++i) {
+               int status;
+
+               if (store_rates)
+                       status = ssnprintf(str_ptr, str_len, ",'gauge'");
+               else
+                       status = ssnprintf(str_ptr, str_len, ",'%s'",
+                                       DS_TYPE_TO_STRING (ds->ds[i].type));
+
+               if (status < 1) {
+                       str_len = 0;
+                       break;
+               }
+               else if ((size_t)status >= str_len) {
+                       str_len = 0;
+                       break;
+               }
+               else {
+                       str_ptr += status;
+                       str_len -= (size_t)status;
+               }
+       }
+
+       if (str_len <= 2) {
+               log_err ("c_psql_write: Failed to stringify value types");
+               return NULL;
+       }
+
+       /* overwrite the first comma */
+       string[0] = '{';
+       str_ptr[0] = '}';
+       str_ptr[1] = '\0';
+
+       return string;
+} /* values_type_to_sqlarray */
+
 static char *values_to_sqlarray (const data_set_t *ds, const value_list_t *vl,
-               char *string, size_t string_len)
+               char *string, size_t string_len, _Bool store_rates)
 {
        char  *str_ptr;
        size_t str_len;
 
+       gauge_t *rates = NULL;
+
        int i;
 
        str_ptr = string;
        str_len = string_len;
 
        for (i = 0; i < vl->values_len; ++i) {
-               int status;
+               int status = 0;
+
+               if ((ds->ds[i].type != DS_TYPE_GAUGE)
+                               && (ds->ds[i].type != DS_TYPE_COUNTER)
+                               && (ds->ds[i].type != DS_TYPE_DERIVE)
+                               && (ds->ds[i].type != DS_TYPE_ABSOLUTE)) {
+                       log_err ("c_psql_write: Unknown data source type: %i",
+                                       ds->ds[i].type);
+                       sfree (rates);
+                       return NULL;
+               }
 
                if (ds->ds[i].type == DS_TYPE_GAUGE)
                        status = ssnprintf (str_ptr, str_len,
                                        ",%f", vl->values[i].gauge);
+               else if (store_rates) {
+                       if (rates == NULL)
+                               rates = uc_get_rate (ds, vl);
+
+                       if (rates == NULL) {
+                               log_err ("c_psql_write: Failed to determine rate");
+                               return NULL;
+                       }
+
+                       status = ssnprintf (str_ptr, str_len,
+                                       ",%lf", rates[i]);
+               }
                else if (ds->ds[i].type == DS_TYPE_COUNTER)
                        status = ssnprintf (str_ptr, str_len,
                                        ",%llu", vl->values[i].counter);
@@ -622,14 +797,11 @@ static char *values_to_sqlarray (const data_set_t *ds, const value_list_t *vl,
                else if (ds->ds[i].type == DS_TYPE_ABSOLUTE)
                        status = ssnprintf (str_ptr, str_len,
                                        ",%"PRIu64, vl->values[i].absolute);
-               else {
-                       log_err ("c_psql_write: Unknown data source type: %i",
-                                       ds->ds[i].type);
-                       return NULL;
-               }
 
-               if (status < 1)
-                       return NULL;
+               if (status < 1) {
+                       str_len = 0;
+                       break;
+               }
                else if ((size_t)status >= str_len) {
                        str_len = 0;
                        break;
@@ -640,6 +812,8 @@ static char *values_to_sqlarray (const data_set_t *ds, const value_list_t *vl,
                }
        }
 
+       sfree (rates);
+
        if (str_len <= 2) {
                log_err ("c_psql_write: Failed to stringify value list");
                return NULL;
@@ -660,9 +834,10 @@ static int c_psql_write (const data_set_t *ds, const value_list_t *vl,
 
        char time_str[32];
        char values_name_str[1024];
+       char values_type_str[1024];
        char values_str[1024];
 
-       const char *params[8];
+       const char *params[9];
 
        int success = 0;
        int i;
@@ -685,9 +860,6 @@ static int c_psql_write (const data_set_t *ds, const value_list_t *vl,
                                values_name_str, sizeof (values_name_str)) == NULL)
                return -1;
 
-       if (values_to_sqlarray (ds, vl, values_str, sizeof (values_str)) == NULL)
-               return -1;
-
 #define VALUE_OR_NULL(v) ((((v) == NULL) || (*(v) == '\0')) ? NULL : (v))
 
        params[0] = time_str;
@@ -697,7 +869,6 @@ static int c_psql_write (const data_set_t *ds, const value_list_t *vl,
        params[4] = vl->type;
        params[5] = VALUE_OR_NULL(vl->type_instance);
        params[6] = values_name_str;
-       params[7] = values_str;
 
 #undef VALUE_OR_NULL
 
@@ -708,12 +879,33 @@ static int c_psql_write (const data_set_t *ds, const value_list_t *vl,
                return -1;
        }
 
+       if ((db->commit_interval > 0)
+                       && (db->next_commit == 0))
+               c_psql_begin (db);
+
        for (i = 0; i < db->writers_num; ++i) {
                c_psql_writer_t *writer;
                PGresult *res;
 
                writer = db->writers[i];
 
+               if (values_type_to_sqlarray (ds,
+                                       values_type_str, sizeof (values_type_str),
+                                       writer->store_rates) == NULL) {
+                       pthread_mutex_unlock (&db->db_lock);
+                       return -1;
+               }
+
+               if (values_to_sqlarray (ds, vl,
+                                       values_str, sizeof (values_str),
+                                       writer->store_rates) == NULL) {
+                       pthread_mutex_unlock (&db->db_lock);
+                       return -1;
+               }
+
+               params[7] = values_type_str;
+               params[8] = values_str;
+
                res = PQexecParams (db->conn, writer->statement,
                                STATIC_ARRAY_SIZE (params), NULL,
                                (const char *const *)params,
@@ -721,10 +913,10 @@ static int c_psql_write (const data_set_t *ds, const value_list_t *vl,
 
                if ((PGRES_COMMAND_OK != PQresultStatus (res))
                                && (PGRES_TUPLES_OK != PQresultStatus (res))) {
+                       PQclear (res);
+
                        if ((CONNECTION_OK != PQstatus (db->conn))
                                        && (0 == c_psql_check_connection (db))) {
-                               PQclear (res);
-
                                /* try again */
                                res = PQexecParams (db->conn, writer->statement,
                                                STATIC_ARRAY_SIZE (params), NULL,
@@ -733,6 +925,7 @@ static int c_psql_write (const data_set_t *ds, const value_list_t *vl,
 
                                if ((PGRES_COMMAND_OK == PQresultStatus (res))
                                                || (PGRES_TUPLES_OK == PQresultStatus (res))) {
+                                       PQclear (res);
                                        success = 1;
                                        continue;
                                }
@@ -745,12 +938,23 @@ static int c_psql_write (const data_set_t *ds, const value_list_t *vl,
                                        writer->statement,
                                        params[0], params[1], params[2], params[3],
                                        params[4], params[5], params[6], params[7]);
+
+                       /* this will abort any current transaction -> restart */
+                       if (db->next_commit > 0)
+                               c_psql_commit (db);
+
                        pthread_mutex_unlock (&db->db_lock);
                        return -1;
                }
+
+               PQclear (res);
                success = 1;
        }
 
+       if ((db->next_commit > 0)
+                       && (cdtime () > db->next_commit))
+               c_psql_commit (db);
+
        pthread_mutex_unlock (&db->db_lock);
 
        if (! success)
@@ -758,10 +962,62 @@ static int c_psql_write (const data_set_t *ds, const value_list_t *vl,
        return 0;
 } /* c_psql_write */
 
+/* We cannot flush single identifiers as all we do is to commit the currently
+ * running transaction, thus making sure that all written data is actually
+ * visible to everybody. */
+static int c_psql_flush (cdtime_t timeout,
+               __attribute__((unused)) const char *ident,
+               user_data_t *ud)
+{
+       c_psql_database_t **dbs = databases;
+       size_t dbs_num = databases_num;
+       size_t i;
+
+       if ((ud != NULL) && (ud->data != NULL)) {
+               dbs = (void *)&ud->data;
+               dbs_num = 1;
+       }
+
+       for (i = 0; i < dbs_num; ++i) {
+               c_psql_database_t *db = dbs[i];
+
+               /* don't commit if the timeout is larger than the regular commit
+                * interval as in that case all requested data has already been
+                * committed */
+               if ((db->next_commit > 0) && (db->commit_interval > timeout))
+                       c_psql_commit (db);
+       }
+       return 0;
+} /* c_psql_flush */
+
 static int c_psql_shutdown (void)
 {
+       size_t i = 0;
+
+       _Bool had_flush = 0;
+
        plugin_unregister_read_group ("postgresql");
 
+       for (i = 0; i < databases_num; ++i) {
+               c_psql_database_t *db = databases[i];
+
+               if (db->writers_num > 0) {
+                       char cb_name[DATA_MAX_NAME_LEN];
+                       ssnprintf (cb_name, sizeof (cb_name), "postgresql-%s",
+                                       db->database);
+
+                       if (! had_flush) {
+                               plugin_unregister_flush ("postgresql");
+                               had_flush = 1;
+                       }
+
+                       plugin_unregister_flush (cb_name);
+                       plugin_unregister_write (cb_name);
+               }
+
+               sfree (db);
+       }
+
        udb_query_free (queries, queries_num);
        queries = NULL;
        queries_num = 0;
@@ -770,6 +1026,10 @@ static int c_psql_shutdown (void)
        writers = NULL;
        writers_num = 0;
 
+       sfree (databases);
+       databases = NULL;
+       databases_num = 0;
+
        return 0;
 } /* c_psql_shutdown */
 
@@ -808,6 +1068,8 @@ static int config_query_param_add (udb_query_t *q, oconfig_item_t *ci)
                data->params[data->params_num] = C_PSQL_PARAM_USER;
        else if (0 == strcasecmp (param_str, "interval"))
                data->params[data->params_num] = C_PSQL_PARAM_INTERVAL;
+       else if (0 == strcasecmp (param_str, "instance"))
+               data->params[data->params_num] = C_PSQL_PARAM_INSTANCE;
        else {
                log_err ("Invalid parameter \"%s\".", param_str);
                return 1;
@@ -903,12 +1165,15 @@ static int c_psql_config_writer (oconfig_item_t *ci)
 
        writer->name = sstrdup (ci->values[0].value.string);
        writer->statement = NULL;
+       writer->store_rates = 1;
 
        for (i = 0; i < ci->children_num; ++i) {
                oconfig_item_t *c = ci->children + i;
 
                if (strcasecmp ("Statement", c->key) == 0)
                        status = cf_util_get_string (c, &writer->statement);
+               else if (strcasecmp ("StoreRates", c->key) == 0)
+                       status = cf_util_get_boolean (c, &writer->store_rates);
                else
                        log_warn ("Ignoring unknown config key \"%s\".", c->key);
        }
@@ -931,6 +1196,8 @@ static int c_psql_config_database (oconfig_item_t *ci)
        struct timespec cb_interval = { 0, 0 };
        user_data_t ud;
 
+       static _Bool have_flush = 0;
+
        int i;
 
        if ((1 != ci->values_num)
@@ -956,6 +1223,8 @@ static int c_psql_config_database (oconfig_item_t *ci)
                        cf_util_get_string (c, &db->user);
                else if (0 == strcasecmp (c->key, "Password"))
                        cf_util_get_string (c, &db->password);
+               else if (0 == strcasecmp (c->key, "Instance"))
+                       cf_util_get_string (c, &db->instance);
                else if (0 == strcasecmp (c->key, "SSLMode"))
                        cf_util_get_string (c, &db->sslmode);
                else if (0 == strcasecmp (c->key, "KRBSrvName"))
@@ -970,6 +1239,8 @@ static int c_psql_config_database (oconfig_item_t *ci)
                                        &db->writers, &db->writers_num);
                else if (0 == strcasecmp (c->key, "Interval"))
                        cf_util_get_cdtime (c, &db->interval);
+               else if (strcasecmp ("CommitInterval", c->key) == 0)
+                       cf_util_get_cdtime (c, &db->commit_interval);
                else
                        log_warn ("Ignoring unknown config key \"%s\".", c->key);
        }
@@ -1012,17 +1283,35 @@ static int c_psql_config_database (oconfig_item_t *ci)
        ud.data = db;
        ud.free_func = c_psql_database_delete;
 
-       ssnprintf (cb_name, sizeof (cb_name), "postgresql-%s", db->database);
+       ssnprintf (cb_name, sizeof (cb_name), "postgresql-%s", db->instance);
 
        if (db->queries_num > 0) {
                CDTIME_T_TO_TIMESPEC (db->interval, &cb_interval);
 
+               ++db->ref_cnt;
                plugin_register_complex_read ("postgresql", cb_name, c_psql_read,
                                /* interval = */ (db->interval > 0) ? &cb_interval : NULL,
                                &ud);
        }
        if (db->writers_num > 0) {
+               ++db->ref_cnt;
                plugin_register_write (cb_name, c_psql_write, &ud);
+
+               if (! have_flush) {
+                       /* flush all */
+                       plugin_register_flush ("postgresql",
+                                       c_psql_flush, /* user data = */ NULL);
+                       have_flush = 1;
+               }
+
+               /* flush this connection only */
+               ++db->ref_cnt;
+               plugin_register_flush (cb_name, c_psql_flush, &ud);
+       }
+       else if (db->commit_interval > 0) {
+               log_warn ("Database '%s': You do not have any writers assigned to "
+                               "this database connection. Setting 'CommitInterval' does "
+                               "not have any effect.", db->database);
        }
        return 0;
 } /* c_psql_config_database */