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Version: Pro Edition for Eclipse Mosquitto 3.2

Settings

The General Platform Settings in the Admin Board let platform administrators set global limits on how the Cedalo MQTT Platform handles data in the UI. These settings control user-facing behavior—such as what the Publish & Subscribe tool may display, how long topic tree data is retained, and how many broker logs are loaded—so that individual brokers or verbose usage cannot overwhelm platform hardware. Limits apply across all projects and brokers connected to the platform; per-broker configuration cannot exceed the caps defined here.

Publish & Subscribe​

Maximum size for published and received messages​

Defines the size limit of a payload shown in the Publish & Subscribe tool. The server still handles the full payload; the client only displays the amount defined here for performance reasons.

High-volume topic subscriptions​

In MQTT, the broker delivers every message that matches a subscription to that client. Topics with a very high publish rate—or broad filters such as # on a busy broker—can send thousands of messages per second to a single subscriber. The Publish & Subscribe tool renders each message in the browser, so such a subscription can overload the session, the broker, and the network. This is especially risky on High Performance (HP) clusters where throughput is already high.

Use High-volume topic subscriptions to limit this in the web client. Configure whether the Publish & Subscribe tool blocks subscriptions to configured topics or warns users before they subscribe. When blocking is enabled, subscription attempts to restricted topics are rejected; when warning is enabled, users must confirm before subscribing.

Topic Tree Settings​

The topic tree records topics seen on each connected broker. On busy brokers it can grow to millions of entries. The platform stores and serves this data to the UI, which increases memory and CPU use on the platform host.

Use Topic Tree Settings to set a maximum time to live (TTL) for topic tree data. This value caps how long topic entries may be kept when TTL is configured on individual brokers, giving global control over retention across all brokers connected to the platform.

Broker Log Limits​

The Platform UI can display broker logs for troubleshooting. At verbose log levels, a single broker can produce millions of log lines. Loading and rendering that volume in the browser can overwhelm platform UI resources.

Use Broker Log Limits to set a maximum number of log entries the UI loads and displays per broker. This caps how much log data the platform holds for the UI at once, similar to the topic tree TTL, so log views stay usable without overloading platform hardware.