Feature/partition precreate window

functions.php

@@ -638,9 +638,10 @@ function syslog_traditional_manage() {
  */
 function syslog_partition_manage() {
 	$syslog_deleted = 0;
+	$ahead_days     = syslog_partition_ahead_days();
 
-	// Always create the partition an hour ahead of time
-	$time = time() + 3600;
+	// Always create partitions ahead of time to avoid midnight races.
+	$base_time = time() + 7200;
 
 	syslog_partition_report_state('syslog');
 	syslog_partition_report_state('syslog_removed');
@@ -651,21 +652,62 @@ function syslog_partition_manage() {
 	 * as the write-path safety net and avoid dropping old partitions
 	 * without a replacement.
 	 */
-	if (syslog_partition_check('syslog', $time)) {
-		if (syslog_partition_create('syslog', $time)) {
-			$syslog_deleted = syslog_partition_remove('syslog');
-		}
+	if (syslog_partition_ensure_ahead('syslog', $base_time, $ahead_days)) {
+		$syslog_deleted = syslog_partition_remove('syslog');
 	}
 
-	if (syslog_partition_check('syslog_removed', $time)) {
-		if (syslog_partition_create('syslog_removed', $time)) {
-			$syslog_deleted += syslog_partition_remove('syslog_removed');
-		}
+	if (syslog_partition_ensure_ahead('syslog_removed', $base_time, $ahead_days)) {
+		$syslog_deleted += syslog_partition_remove('syslog_removed');
 	}
 
 	return $syslog_deleted;
 }
 
+/**
+ * Return the configured number of future daily partitions to maintain.
+ *
+ * @return int Days ahead to pre-create.
+ */
+function syslog_partition_ahead_days() {
+	$ahead_days = read_config_option('syslog_partition_ahead_days');
+
+	if ($ahead_days === '' || !is_numeric($ahead_days)) {
+		$ahead_days = 3;
+	}
+
+	$ahead_days = (int) $ahead_days;
+
+	if ($ahead_days < 1 || $ahead_days > 7) {
+		$ahead_days = 3;
+	}
+
+	return $ahead_days;
+}
+
+/**
+ * Ensure concrete partitions exist from the current window through the
+ * configured future horizon.
+ *
+ * @param string $table      The table to maintain
+ * @param int    $base_time  Base timestamp for the maintenance window
+ * @param int    $ahead_days Number of future days to maintain
+ *
+ * @return bool true when all needed partitions already exist or were created.
+ */
+function syslog_partition_ensure_ahead($table, $base_time, $ahead_days) {
+	for ($day = 0; $day <= $ahead_days; $day++) {
+		$time = $base_time + ($day * 86400);
+
+		if (syslog_partition_check($table, $time)) {
+			if (!syslog_partition_create($table, $time)) {
+				return false;
+			}
+		}
+	}
+
+	return true;
+}
+
 /**
  * Validate tables that support partition maintenance.
  *
@@ -965,17 +1007,19 @@ function syslog_partition_remove($table) {
 			ORDER BY partition_ordinal_position',
 			[$syslogdb_default, $table]);
 
-		$days = read_config_option('syslog_retention');
+		$days       = read_config_option('syslog_retention');
+		$ahead_days = syslog_partition_ahead_days();
 
-		syslog_debug("There are currently '" . sizeof($number_of_partitions) . "' Syslog Partitions, We will keep '$days' of them.");
+		syslog_debug("There are currently '" . sizeof($number_of_partitions) . "' Syslog Partitions, We will keep '$days' retention partition(s) plus '$ahead_days' future partition(s).");
 
 		if ($days > 0) {
 			$user_partitions = sizeof($number_of_partitions) - 1;
+			$keep_partitions = (int) $days + $ahead_days;
 
-			if ($user_partitions >= $days) {
+			if ($user_partitions >= $keep_partitions) {
 				$i = 0;
 
-				while ($user_partitions > $days) {
+				while ($user_partitions > $keep_partitions) {
 					$oldest = $number_of_partitions[$i];
 
 					$part_name = $oldest['PARTITION_NAME'];
@@ -3490,6 +3534,7 @@ function syslog_process_log($start_time, $deleted, $incoming, $removed, $xferred
 function syslog_init_variables() {
 	$syslog_retention = read_config_option('syslog_retention');
 	$alert_retention  = read_config_option('syslog_alert_retention');
+	$ahead_days       = read_config_option('syslog_partition_ahead_days');
 
 	if ($syslog_retention == '' || $syslog_retention < 0 || $syslog_retention > 365) {
 		set_config_option('syslog_retention', '30');
@@ -3499,6 +3544,10 @@ function syslog_init_variables() {
 		set_config_option('syslog_alert_retention', '30');
 	}
 
+	if ($ahead_days == '' || !is_numeric($ahead_days) || $ahead_days < 1 || $ahead_days > 7) {
+		set_config_option('syslog_partition_ahead_days', '3');
+	}
+
 	if (substr(read_config_option('base_url'), 0, 4) != 'http') {
 		if (read_config_option('force_https') == 'on') {
 			$prefix = 'https://';

setup.php

@@ -492,7 +492,7 @@ function syslog_check_upgrade() {
 	}
 }
 
-function syslog_create_partitioned_syslog_table($engine = 'InnoDB', $days = 30) {
+function syslog_create_partitioned_syslog_table($engine = 'InnoDB', $days = 30, $ahead_days = 3) {
 	global $config, $syslogdb_default, $syslog_levels;
 
 	syslog_connect();
@@ -508,6 +508,12 @@ function syslog_create_partitioned_syslog_table($engine = 'InnoDB', $days = 30)
 		$days = 30;
 	}
 
+	if (!is_numeric($ahead_days) || (int) $ahead_days < 1 || (int) $ahead_days > 7) {
+		$ahead_days = 3;
+	}
+
+	$ahead_days = (int) $ahead_days;
+
 	if (stripos($engine, 'aria') !== false) {
 		$row_format = 'ROW_FORMAT=Page';
 	} else {
@@ -543,7 +549,7 @@ function syslog_create_partitioned_syslog_table($engine = 'InnoDB', $days = 30)
 	 * out of the equation: the boundary is always the next UTC midnight
 	 * after the labeled day.
 	 */
-	for ($i = $days; $i >= -1; $i--) {
+	for ($i = $days; $i >= (0 - $ahead_days); $i--) {
 		$day_epoch      = $now - ($i * 86400);
 		$boundary_epoch = (intdiv($day_epoch, 86400) + 1) * 86400;
 		$format         = gmdate('Ymd', $day_epoch);
@@ -648,7 +654,7 @@ function syslog_setup_table_new($options) {
 
 	// The syslog table is created partitioned; the helper also selects the
 	// matching ROW_FORMAT for the chosen engine.
-	syslog_create_partitioned_syslog_table($engine, $options['days']);
+	syslog_create_partitioned_syslog_table($engine, $options['days'], read_config_option('syslog_partition_ahead_days'));
 
 	if ($truncate) {
 		syslog_db_execute("DROP TABLE IF EXISTS `$syslogdb_default`.`syslog_alert`");
@@ -1312,6 +1318,21 @@ function syslog_config_settings() {
 			'default'       => '30',
 			'array'         => $syslog_retentions
 		],
+		'syslog_partition_ahead_days' => [
+			'friendly_name' => __('Partition Pre-create Window', 'syslog'),
+			'description'   => __('This is the number of future daily partitions to maintain for partitioned Syslog tables.', 'syslog'),
+			'method'        => 'drop_array',
+			'default'       => '3',
+			'array'         => [
+				'1' => __('%d Day', 1, 'syslog'),
+				'2' => __('%d Days', 2, 'syslog'),
+				'3' => __('%d Days', 3, 'syslog'),
+				'4' => __('%d Days', 4, 'syslog'),
+				'5' => __('%d Days', 5, 'syslog'),
+				'6' => __('%d Days', 6, 'syslog'),
+				'7' => __('%d Days', 7, 'syslog')
+			]
+		],
 		'syslog_alert_retention' => [
 			'friendly_name' => __('Syslog Alert Retention', 'syslog'),
 			'description'   => __('This is the number of days to keep alert logs.', 'syslog'),

tests/Security/PartitionTableLockingTest.php

@@ -234,7 +234,7 @@
 		throw new RuntimeException("syslog_partition_create does not log a warning when the partition expression can't be determined.");
 	}
 
-	// ---- syslog_partition_manage must exist and drive both tables through check/create/remove ----
+	// ---- syslog_partition_manage must exist and drive both tables through ensure/remove ----
 
 	$manage_start = strpos($functions, 'function syslog_partition_manage');
 
@@ -251,12 +251,8 @@
 	$manage_body = substr($functions, $manage_start, $manage_end - $manage_start);
 
 	foreach (['syslog', 'syslog_removed'] as $table) {
-		if (!preg_match('/syslog_partition_report_state\s*\(\s*\'' . $table . '\'\s*\)/', $manage_body)) {
-			throw new RuntimeException("syslog_partition_manage does not report partition state for '$table'.");
-		}
-
-		if (!preg_match('/syslog_partition_create\s*\(\s*\'' . $table . '\'/', $manage_body)) {
-			throw new RuntimeException("syslog_partition_manage does not call syslog_partition_create('$table').");
+		if (!preg_match('/syslog_partition_ensure_ahead\s*\(\s*\'' . $table . '\'/', $manage_body)) {
+			throw new RuntimeException("syslog_partition_manage does not ensure future partitions for '$table'.");
 		}
 
 		if (!preg_match('/syslog_partition_remove\s*\(\s*\'' . $table . '\'\s*\)/', $manage_body)) {

tests/Unit/PartitionAheadTest.php

@@ -0,0 +1,130 @@
+<?php
+/*
+ +-------------------------------------------------------------------------+
+ | Copyright (C) 2004-2026 The Cacti Group                                 |
+ +-------------------------------------------------------------------------+
+ | Cacti: The Complete RRDTool-based Graphing Solution                     |
+ +-------------------------------------------------------------------------+
+*/
+
+it('defaults partition pre-create window to three days and clamps invalid values', function () {
+	syslog_load_plugin_source('functions.php');
+
+	test_override('read_config_option', function ($name) {
+		return $name === 'syslog_partition_ahead_days' ? '' : '';
+	});
+
+	expect(syslog_partition_ahead_days())->toBe(3);
+
+	foreach (['0', '8', '-1', 'abc'] as $invalid) {
+		test_override('read_config_option', function ($name) use ($invalid) {
+			return $name === 'syslog_partition_ahead_days' ? $invalid : '';
+		});
+
+		expect(syslog_partition_ahead_days())->toBe(3);
+	}
+
+	test_override('read_config_option', function ($name) {
+		return $name === 'syslog_partition_ahead_days' ? '7' : '';
+	});
+
+	expect(syslog_partition_ahead_days())->toBe(7);
+});
+
+it('ensures partitions sequentially through the configured future horizon', function () {
+	syslog_load_plugin_source('functions.php');
+
+	$created = [];
+	$last_partition = '20260914';
+	$base_time = gmmktime(22, 30, 0, 9, 15, 2026);
+
+	$GLOBALS['syslogdb_default'] = 'syslog';
+
+	test_override('syslog_db_fetch_cell_prepared', function ($sql) use (&$last_partition) {
+		if (str_contains($sql, 'GET_LOCK') || str_contains($sql, 'RELEASE_LOCK')) {
+			return 1;
+		}
+
+		if (str_contains($sql, 'PARTITION_NAME')) {
+			return 'd' . $last_partition;
+		}
+
+		return '';
+	});
+
+	test_override('syslog_db_fetch_row_prepared', function ($sql, $params = []) {
+		if (str_contains($sql, 'information_schema')) {
+			return [];
+		}
+
+		if (str_contains($sql, 'SHOW CREATE TABLE')) {
+			return ['Create Table' => 'CREATE TABLE `syslog` (`logtime` timestamp NOT NULL) PARTITION BY RANGE (UNIX_TIMESTAMP(logtime))'];
+		}
+
+		return [];
+	});
+
+	test_override('syslog_db_execute_prepared', function ($sql) use (&$created, &$last_partition) {
+		if (preg_match('/PARTITION (d\d{8}) VALUES LESS THAN/', $sql, $matches)) {
+			$created[] = $matches[1];
+			$last_partition = substr($matches[1], 1);
+		}
+
+		return true;
+	});
+
+	expect(syslog_partition_ensure_ahead('syslog', $base_time, 3))->toBeTrue();
+	expect($created)->toBe([
+		'd20260915',
+		'd20260916',
+		'd20260917',
+		'd20260918'
+	]);
+});
+
+it('keeps retention plus future partitions when pruning', function () {
+	syslog_load_plugin_source('functions.php');
+
+	$GLOBALS['syslogdb_default'] = 'syslog';
+	$dropped = [];
+
+	test_override('read_config_option', function ($name) {
+		if ($name === 'syslog_retention') {
+			return '3';
+		}
+
+		if ($name === 'syslog_partition_ahead_days') {
+			return '3';
+		}
+
+		return '';
+	});
+
+	test_override('syslog_db_fetch_cell_prepared', function () {
+		return 1;
+	});
+
+	test_override('syslog_db_fetch_assoc_prepared', function () {
+		return [
+			['PARTITION_NAME' => 'd20260910'],
+			['PARTITION_NAME' => 'd20260911'],
+			['PARTITION_NAME' => 'd20260912'],
+			['PARTITION_NAME' => 'd20260913'],
+			['PARTITION_NAME' => 'd20260914'],
+			['PARTITION_NAME' => 'd20260915'],
+			['PARTITION_NAME' => 'd20260916'],
+			['PARTITION_NAME' => 'dMaxValue']
+		];
+	});
+
+	test_override('syslog_db_execute_prepared', function ($sql) use (&$dropped) {
+		if (preg_match('/DROP PARTITION `([^`]+)`/', $sql, $matches)) {
+			$dropped[] = $matches[1];
+		}
+
+		return true;
+	});
+
+	expect(syslog_partition_remove('syslog'))->toBe(1);
+	expect($dropped)->toBe(['d20260910']);
+});