postgresql plugin: Define default queries in a configuration file.

Instead of writing custom code for each default query, those are now defined
in a configuration file which is parsed using the same mechanism as used for
user-defined queries. This configuration file (postgresql_default.conf) is
installed into $pkgdatadir.

Querying the pg_stat_database view is not currently supported this way. This
would require support for parameters in user-defined queries which is not
(yet) available.

Signed-off-by: Sebastian Harl <sh@tokkee.org>
Signed-off-by: Florian Forster <octo@huhu.verplant.org>

diff --git a/src/Makefile.am b/src/Makefile.am
index c4e7d69..dc36a2a 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -21,6 +21,7 @@ if BUILD_FEATURE_DAEMON
 AM_CPPFLAGS += -DPIDFILE='"${localstatedir}/run/${PACKAGE_NAME}.pid"'
 endif
 AM_CPPFLAGS += -DPLUGINDIR='"${pkglibdir}"'
+AM_CPPFLAGS += -DPKGDATADIR='"${pkgdatadir}"'
 
 sbin_PROGRAMS = collectd collectdmon
 bin_PROGRAMS = collectd-nagios
@@ -796,3 +797,5 @@ install-exec-hook:
                $(INSTALL) -m 0640 collectd.conf $(DESTDIR)$(sysconfdir)/collectd.conf; \
        fi; \
        cp -f $(srcdir)/types.db $(DESTDIR)$(pkglibdir)/;
+       $(INSTALL) -D -m 0644 $(srcdir)/postgresql_default.conf \
+               $(DESTDIR)$(pkgdatadir)/postgresql_default.conf;

diff --git a/src/collectd.h b/src/collectd.h
index a262bf1..196530f 100644 (file)
--- a/src/collectd.h
+++ b/src/collectd.h
@@ -239,6 +239,10 @@
 #define PLUGINDIR PREFIX "/lib/" PACKAGE_NAME
 #endif
 
+#ifndef PKGDATADIR
+#define PKGDATADIR PREFIX "/share/" PACKAGE_NAME
+#endif
+
 #ifndef COLLECTD_GRP_NAME
 # define COLLECTD_GRP_NAME "collectd"
 #endif

diff --git a/src/postgresql.c b/src/postgresql.c
index 6a270d8..5c5fbb3 100644 (file)
--- a/src/postgresql.c
+++ b/src/postgresql.c
@@ -38,6 +38,10 @@
 #define log_warn(...) WARNING ("postgresql: " __VA_ARGS__)
 #define log_info(...) INFO ("postgresql: " __VA_ARGS__)
 
+#ifndef C_PSQL_DEFAULT_CONF
+# define C_PSQL_DEFAULT_CONF PKGDATADIR "/postgresql_default.conf"
+#endif
+
 /* Appends the (parameter, value) pair to the string
  * pointed to by 'buf' suitable to be used as argument
  * for PQconnectdb(). If value equals NULL, the pair
@@ -107,6 +111,12 @@ typedef struct {
        char *service;
 } c_psql_database_t;
 
+static char *def_queries[] = {
+       "user_tables",
+       "io_user_tables"
+};
+static int def_queries_num = STATIC_ARRAY_SIZE (def_queries);
+
 static c_psql_query_t *queries          = NULL;
 static int             queries_num      = 0;
 
@@ -393,97 +403,6 @@ static int c_psql_stat_database (c_psql_database_t *db)
        return 0;
 } /* c_psql_stat_database */
 
-static int c_psql_stat_user_tables (c_psql_database_t *db)
-{
-       const char *const query =
-               "SELECT sum(seq_scan), sum(seq_tup_read), "
-                               "sum(idx_scan), sum(idx_tup_fetch), "
-                               "sum(n_tup_ins), sum(n_tup_upd), sum(n_tup_del), "
-                               "sum(n_tup_hot_upd), sum(n_live_tup), sum(n_dead_tup) "
-                       "FROM pg_stat_user_tables;";
-
-       PGresult *res;
-
-       int n;
-
-       res = PQexec (db->conn, query);
-
-       if (PGRES_TUPLES_OK != PQresultStatus (res)) {
-               log_err ("Failed to execute SQL query: %s",
-                               PQerrorMessage (db->conn));
-               log_info ("SQL query was: %s", query);
-               PQclear (res);
-               return -1;
-       }
-
-       n = PQntuples (res);
-       assert (1 >= n);
-
-       if (1 > n) /* no user tables */
-               return 0;
-
-       submit_counter (db, "pg_scan", "seq",           PQgetvalue (res, 0, 0));
-       submit_counter (db, "pg_scan", "seq_tup_read",  PQgetvalue (res, 0, 1));
-       submit_counter (db, "pg_scan", "idx",           PQgetvalue (res, 0, 2));
-       submit_counter (db, "pg_scan", "idx_tup_fetch", PQgetvalue (res, 0, 3));
-
-       submit_counter (db, "pg_n_tup_c", "ins",        PQgetvalue (res, 0, 4));
-       submit_counter (db, "pg_n_tup_c", "upd",        PQgetvalue (res, 0, 5));
-       submit_counter (db, "pg_n_tup_c", "del",        PQgetvalue (res, 0, 6));
-       submit_counter (db, "pg_n_tup_c", "hot_upd",    PQgetvalue (res, 0, 7));
-
-       submit_gauge (db, "pg_n_tup_g", "live",         PQgetvalue (res, 0, 8));
-       submit_gauge (db, "pg_n_tup_g", "dead",         PQgetvalue (res, 0, 9));
-
-       PQclear (res);
-       return 0;
-} /* c_psql_stat_user_tables */
-
-static int c_psql_statio_user_tables (c_psql_database_t *db)
-{
-       const char *const query =
-               "SELECT sum(heap_blks_read), sum(heap_blks_hit), "
-                               "sum(idx_blks_read), sum(idx_blks_hit), "
-                               "sum(toast_blks_read), sum(toast_blks_hit), "
-                               "sum(tidx_blks_read), sum(tidx_blks_hit) "
-                       "FROM pg_statio_user_tables;";
-
-       PGresult *res;
-
-       int n;
-
-       res = PQexec (db->conn, query);
-
-       if (PGRES_TUPLES_OK != PQresultStatus (res)) {
-               log_err ("Failed to execute SQL query: %s",
-                               PQerrorMessage (db->conn));
-               log_info ("SQL query was: %s", query);
-               PQclear (res);
-               return -1;
-       }
-
-       n = PQntuples (res);
-       assert (1 >= n);
-
-       if (1 > n) /* no user tables */
-               return 0;
-
-       submit_counter (db, "pg_blks", "heap_read",  PQgetvalue (res, 0, 0));
-       submit_counter (db, "pg_blks", "heap_hit",   PQgetvalue (res, 0, 1));
-
-       submit_counter (db, "pg_blks", "idx_read",   PQgetvalue (res, 0, 2));
-       submit_counter (db, "pg_blks", "idx_hit",    PQgetvalue (res, 0, 3));
-
-       submit_counter (db, "pg_blks", "toast_read", PQgetvalue (res, 0, 4));
-       submit_counter (db, "pg_blks", "toast_hit",  PQgetvalue (res, 0, 5));
-
-       submit_counter (db, "pg_blks", "tidx_read",  PQgetvalue (res, 0, 6));
-       submit_counter (db, "pg_blks", "tidx_hit",   PQgetvalue (res, 0, 7));
-
-       PQclear (res);
-       return 0;
-} /* c_psql_statio_user_tables */
-
 static int c_psql_read (void)
 {
        int success = 0;
@@ -500,8 +419,6 @@ static int c_psql_read (void)
                        continue;
 
                c_psql_stat_database (db);
-               c_psql_stat_user_tables (db);
-               c_psql_statio_user_tables (db);
 
                for (j = 0; j < db->queries_num; ++j)
                        c_psql_exec_query (db, j);
@@ -761,13 +678,46 @@ static int c_psql_config_database (oconfig_item_t *ci)
                else
                        log_warn ("Ignoring unknown config key \"%s\".", c->key);
        }
+
+       if (NULL == db->queries) {
+               db->queries = (c_psql_query_t **)malloc (def_queries_num
+                               * sizeof (*db->queries));
+
+               for (i = 0; i < def_queries_num; ++i) {
+                       db->queries[i] = c_psql_query_get (def_queries[i]);
+                       if (NULL == db->queries[i])
+                               log_err ("Query \"%s\" not found - "
+                                               "please check your installation.",
+                                               def_queries[i]);
+                       else
+                               ++db->queries_num;
+               }
+       }
        return 0;
 }
 
 static int c_psql_config (oconfig_item_t *ci)
 {
+       static int have_def_config = 0;
+
        int i;
 
+       if (0 == have_def_config) {
+               oconfig_item_t *c;
+
+               have_def_config = 1;
+
+               c = oconfig_parse_file (C_PSQL_DEFAULT_CONF);
+               if (NULL == c)
+                       log_err ("Failed to read default config ("C_PSQL_DEFAULT_CONF").");
+               else
+                       c_psql_config (c);
+
+               if (NULL == queries)
+                       log_err ("Default config ("C_PSQL_DEFAULT_CONF") did not define "
+                                       "any queries - please check your installation.");
+       }
+
        for (i = 0; i < ci->children_num; ++i) {
                oconfig_item_t *c = ci->children + i;
 

diff --git a/src/postgresql_default.conf b/src/postgresql_default.conf
new file mode 100644 (file)
index 0000000..1391147
--- /dev/null
+++ b/src/postgresql_default.conf
@@ -0,0 +1,38 @@
+# Pre-defined queries of collectd's postgresql plugin.
+
+<Query user_tables>
+       Query "SELECT sum(seq_scan), sum(seq_tup_read), \
+                       sum(idx_scan), sum(idx_tup_fetch), \
+                       sum(n_tup_ins), sum(n_tup_upd), sum(n_tup_del), \
+                       sum(n_tup_hot_upd), sum(n_live_tup), sum(n_dead_tup) \
+               FROM pg_stat_user_tables"
+
+       Column pg_scan    seq
+       Column pg_scan    seq_tup_read
+       Column pg_scan    idx
+       Column pg_scan    idx_tup_fetch
+       Column pg_n_tup_c ins
+       Column pg_n_tup_c upd
+       Column pg_n_tup_c del
+       Column pg_n_tup_c hot_upd
+       Column pg_n_tup_g live
+       Column pg_n_tup_g dead
+</Query>
+
+<Query io_user_tables>
+       Query "SELECT sum(heap_blks_read), sum(heap_blks_hit), \
+                       sum(idx_blks_read), sum(idx_blks_hit), \
+                       sum(toast_blks_read), sum(toast_blks_hit), \
+                       sum(tidx_blks_read), sum(tidx_blks_hit) \
+               FROM pg_statio_user_tables;"
+
+       Column pg_blks heap_read
+       Column pg_blks heap_hit
+       Column pg_blks idx_read
+       Column pg_blks idx_hit
+       Column pg_blks toast_read
+       Column pg_blks toast_hit
+       Column pg_blks tidx_read
+       Column pg_blks tidx_hit
+</Query>
+