Zabbix

/*

** Zabbix

** Copyright (C) 2001-2022 Zabbix SIA

**

** This program is free software; you can redistribute it and/or modify

** it under the terms of the GNU General Public License as published by

** the Free Software Foundation; either version 2 of the License, or

** (at your option) any later version.

**

** This program is distributed in the hope that it will be useful,

** but WITHOUT ANY WARRANTY; without even the implied warranty of

** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

** GNU General Public License for more details.

**

** You should have received a copy of the GNU General Public License

** along with this program; if not, write to the Free Software

** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

**/

​

package postgres

​

import (

    "context"

    "errors"

​

    "git.zabbix.com/ap/plugin-support/zbxerr"

    "github.com/jackc/pgx/v4"

)

​

// archiveHandler gets info about count and size of archive files and returns JSON if all is OK or nil otherwise.

func archiveHandler(ctx context.Context, conn PostgresClient,

    _ string, _ map[string]string, _ ...string) (interface{}, error) {

    var archiveCountJSON, archiveSizeJSON string

​

    queryArchiveCount := `SELECT row_to_json(T)

                            FROM (

                                    SELECT archived_count, failed_count

                                      FROM pg_stat_archiver

                                ) T;`

​

    queryArchiveSize := `SELECT row_to_json(T)

                            FROM (

                                WITH values AS (

                                    SELECT

                                        4096/(ceil(pg_settings.setting::numeric/1024/1024))::int AS segment_parts_count,

                                        setting::bigint AS segment_size,

                                        ('x' || substring(pg_stat_archiver.last_archived_wal from 9 for 8))::bit(32)::int AS last_wal_div,

                                        ('x' || substring(pg_stat_archiver.last_archived_wal from 17 for 8))::bit(32)::int AS last_wal_mod,

                                        CASE WHEN pg_is_in_recovery() THEN NULL 

                                            ELSE ('x' || substring(pg_walfile_name(pg_current_wal_lsn()) from 9 for 8))::bit(32)::int END AS current_wal_div,

                                        CASE WHEN pg_is_in_recovery() THEN NULL 

                                            ELSE ('x' || substring(pg_walfile_name(pg_current_wal_lsn()) from 17 for 8))::bit(32)::int END AS current_wal_mod

                                    FROM pg_settings, pg_stat_archiver

                                    WHERE pg_settings.name = 'wal_segment_size')

                                SELECT 

                                    greatest(coalesce((segment_parts_count - last_wal_mod) + ((current_wal_div - last_wal_div - 1) * segment_parts_count) + current_wal_mod - 1, 0), 0) AS count_files,

                                    greatest(coalesce(((segment_parts_count - last_wal_mod) + ((current_wal_div - last_wal_div - 1) * segment_parts_count) + current_wal_mod - 1) * segment_size, 0), 0) AS size_files

                                FROM values

                            ) T;`

​

    row, err := conn.QueryRow(ctx, queryArchiveCount)

    if err != nil {

        return nil, zbxerr.ErrorCannotFetchData.Wrap(err)