HiveMQ 4.46.1 Maintenance Release

The HiveMQ team is pleased to announce the availability of HiveMQ 4.46.1.

This maintenance release for 4.46 includes the following improvements:

HiveMQ Enterprise MQTT Broker

• Fixed an issue to ensure correct publish payload persistence cleanup, regardless of the number of CPU cores.

Details

HiveMQ 4.46.1 resolves a critical configuration issue that affects HiveMQ versions 4.44 through 4.46.

A configuration bug related to persistence cleanup has been detected on clusters that run nodes with particular CPU core counts.

Use the following formula to determine whether your deployment is affected:

Formula: f(X) = 4 × X² (where X = number of CPU cores per node)

Your configuration is affected if: f(X) mod 64 ≠ 0

Examples:

• 12 cores: f(12) = 576 = 9×64 — NOT Affected
• 6 cores: f(6) = 144 — AFFECTED (not divisible by 64)
• 3 cores: f(3) = 36 — AFFECTED (not divisible by 64)

Impact

Message payloads are not completely cleaned up from disk, leading to gradual disk space consumption. Over time, this can cause the disk to fill up and result in node instability or failure.

Recommended Action

Check your node configurations against the provided formula.

If affected, upgrade to 4.46.1 or higher immediately.

TIP: After the upgrade, check the disk usage in the cluster-backup sub-folder. If it's too large and the cluster is healthy, it could be safely removed.

Have a great day, The HiveMQ Team