From: Sebastian Harl Date: Thu, 15 Nov 2012 12:29:20 +0000 (+0100) Subject: postgresql plugin: Added support for "flushing" data. X-Git-Tag: collectd-5.2.0~13^2~4 X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=27b225794cf5774bc1c34ad431bbabd2cc3971b9;p=collectd.git postgresql plugin: Added support for "flushing" data. This may be used to commit a PostgreSQL writer's transaction. Two different types of flush callbacks are registered: - postgresql: Flush *all* databases. - postgresql-: Flush the database named '' only. --- diff --git a/src/postgresql.c b/src/postgresql.c index ef7a5ec1..9f4894ca 100644 --- a/src/postgresql.c +++ b/src/postgresql.c @@ -934,10 +934,41 @@ 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 = 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)) + if (c_psql_commit (db) == 0) + c_psql_begin (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) { @@ -947,6 +978,13 @@ static int c_psql_shutdown (void) 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); } } @@ -1127,6 +1165,8 @@ 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) @@ -1223,6 +1263,17 @@ static int c_psql_config_database (oconfig_item_t *ci) 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 "