[TheWitness]

Description

syslog_partition_create() decided whether a daily partition was missing purely by name (e.g. d20261112). When that name was absent it unconditionally issued:

ALTER TABLE `syslog` REORGANIZE PARTITION dMaxValue INTO (
    PARTITION d20261112 VALUES LESS THAN (TO_DAYS('2026-11-13')),
    PARTITION dMaxValue VALUES LESS THAN MAXVALUE)

A REORGANIZE of dMaxValue only succeeds when the new boundary is strictly greater than every existing concrete boundary. On a table carried over from an older TO_DAYS schema — or one left inconsistent by an interrupted 4.2 → 4.11 upgrade — an existing partition can already reach or exceed that day's boundary under a different name. The name-only check never detected this, so the ALTER was rejected by MySQL with:

Error 1493: VALUES LESS THAN value must be strictly increasing for each partition

Because syslog_partition_recover() stops on the first create failure, recovery wedged permanently: every poller cycle re-emitted the doomed REORGANIZE, logged the same errors, and left new rows parked in the dMaxValue safety partition while retention pruning stayed deferred.

This change adds a boundary-aware guard. Before issuing the REORGANIZE, it reads the highest existing concrete boundary (MAX(partition_description)) and the partition expression from information_schema.PARTITIONS, computes the target boundary in the table's native units (TO_DAYS(...) or the epoch literal), and if the day is already covered (target <= max existing boundary) treats it as a successful no-op instead of emitting DDL that cannot succeed. Genuinely new partitions (target beyond the current range) are still created exactly as before.

Related Issue

Fixes #434 — "Cacti 1.2.3x Syslog 4.11. to 4.2 missing table & VALUES LESS THAN error on creation of partition". The user's log shows the exact failing statement and MySQL error 1493 on both syslog and syslog_removed, repeating every poller cycle.

Motivation and Context

The missing-column error in that issue was already addressed by #439; the remaining, still-reproducing symptom is this partition-creation crash loop. The fix is scoped to the creation path where the DDL is emitted, so recovery no longer wedges regardless of how the legacy/partly-upgraded table reached its current partition layout.

How Has This Been Tested?

Ran the plugin's Pest suite against a Cacti checkout with the plugin at plugins/syslog:

include/vendor/bin/pest --configuration plugins/syslog/phpunit.xml

Result: 647 passed (2695 assertions), with 1 pre-existing unrelated warning (/proc cmdline stub in ProcessHelperCompatTest).

Added tests/Unit/PartitionReorganizeCoverageTest.php with three cases:

• an already-covered TO_DAYS day → no REORGANIZE issued, returns success, lock released;
• an already-covered UNIX_TIMESTAMP day → same;
• a genuinely new boundary that extends the range → the REORGANIZE is still issued.

The existing partition-create/overflow/recovery tests continue to pass unchanged (the new information_schema lookup is inert under their stubs, preserving current behavior).

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation repository accordingly.

[Copilot]

🟡 Changes recommended

Recovery counts already-covered days against its creation budget, leaving needed partitions uncreated and repeatedly deferring retention.

1 open issue

• Covered days consume recovery slots and defer missing partition creation · New

What changed in this PR

This PR addresses the partition-creation error reported in #434 by checking existing boundaries before splitting dMaxValue, complementing the upgrade compatibility fixes in #439.

Changes:

• Skip partition creation when an existing TO_DAYS or epoch boundary already covers the requested day.
• Add tests for covered-day no-ops, lock release, and creation beyond the existing range.
• Document the fix in the development changelog.

File	Description
tests/​Unit/​PartitionReorganizeCoverageTest.php	Adds boundary-aware partition creation regression tests.
includes/​functions.php	Guards against REORGANIZE statements with already-covered boundaries.
CHANGELOG.md	Documents the partition recovery fix for #434.

_{Review effort: Balanced}

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud