Tenant-level Settings

Tenant-level settings allow for detailed control of BifroMQ's functionality and performance characteristics. Each setting can be adjusted per tenant, enabling customized behavior according to the specific requirements and preferences of each tenant. This granularity ensures that BifroMQ can cater to a wide variety of use cases and operational environments.

Initial Value Adjustment

Initial values for these settings can be adjusted through JVM startup parameters. This allows for system-wide default adjustments before runtime customization per tenant. For example, to disable MQTT version 3.1 client connections by default, you can start the JVM with the parameter -DMQTT3Enabled=false. This level of control provides the flexibility to optimize the broker's behavior based on the deployment context and operational requirements.

Customization through Setting Provider Plugins

The management responsibility of tenant settings is inverted, meaning it is implemented by the business side. Customization and runtime adjustment of these settings are achieved through the development and integration of custom Setting Provider plugins. This approach allows businesses to dynamically adjust settings in response to changing operational conditions, regulatory requirements, or specific business logic, enhancing the adaptability and scalability of BifroMQ deployments.

Supported Settings

Name	Type	Initial Value	Description
MQTT3Enabled	Boolean	true	Enables or disables MQTT v3.1 support.
MQTT4Enabled	Boolean	true	Enables or disables MQTT v3.1.1 support.
MQTT5Enabled	Boolean	true	Enables or disables MQTT v5.0 support.
NoLWTWhenServerShuttingDown	Boolean	true	Suppresses Last Will delivery when the server is shutting down.
DebugModeEnabled	Boolean	false	Enables or disables debug mode.
ForceTransient	Boolean	false	Forces transient mode for connections.
ByPassPermCheckError	Boolean	true	Bypasses permission check errors.
PayloadFormatValidationEnabled	Boolean	true	Enables or disables payload format validation.
RetainEnabled	Boolean	true	Enables or disables message retain feature.
WildcardSubscriptionEnabled	Boolean	true	Enables or disables wildcard subscriptions.
SubscriptionIdentifierEnabled	Boolean	true	Enables or disables subscription identifiers.
SharedSubscriptionEnabled	Boolean	true	Enables or disables shared subscriptions.
MaximumQoS	Integer	2	Maximum QoS level. Valid values: 0, 1, 2.
MaxTopicLevelLength	Integer	40	Maximum length of each topic level (> 0).
MaxTopicLevels	Integer	16	Maximum number of topic levels (> 0).
MaxTopicLength	Integer	255	Maximum total topic length (< 65536).
MaxTopicAlias	Integer	10	Maximum number of topic aliases (< 65536).
MaxSharedGroupMembers	Integer	200	Maximum members in a shared subscription group (> 0).
MaxTopicFiltersPerInbox	Integer	100	Maximum topic filters per inbox (> 0).
MsgPubPerSec	Integer	200	Maximum publishes per second per connection (> 0, ≤ 1000).
ReceivingMaximum	Integer	200	Maximum in-flight QoS 1/2 messages per connection (> 0, ≤ 65535).
InBoundBandWidth	Long	512 * 1024L	Maximum inbound bandwidth per connection in bytes (≥ 0).
OutBoundBandWidth	Long	512 * 1024L	Maximum outbound bandwidth per connection in bytes (≥ 0).
MaxLastWillBytes	Integer	128	Maximum Last Will payload size in bytes (> 0, ≤ 250 * 1024 * 1024).
MaxUserPayloadBytes	Integer	256 * 1024	Maximum user payload size in bytes (> 0, ≤ 256 * 1024 * 1024).
MinSendPerSec	Integer	8	Minimum allowed publishes per second per connection (> 0).
MaxResendTimes	Integer	3	Maximum resend attempts for QoS 1/2 messages (≥ 0).
ResendTimeoutSeconds	Integer	10	Timeout in seconds before a message is considered for resend (> 0).
MaxTopicFiltersPerSub	Integer	10	Maximum topic filters per subscription (> 0, ≤ 100).
MaxGroupFanout	Integer	100	Maximum fanout for group deliveries (> 0).
MaxPersistentFanout	Integer	Integer.MAX_VALUE	Maximum persistent fanout concurrency (> 0).
MaxPersistentFanoutBytes	Long	Long.MAX_VALUE	Maximum bytes allowed for persistent fanout (> 0).
MaxSessionExpirySeconds	Integer	24 * 60 * 60	Maximum session expiry time in seconds (> 0, ≤ 0xFFFFFFFF).
MinSessionExpirySeconds	Integer	60	Minimum session expiry time in seconds (> 0, ≤ MaxSessionExpirySeconds).
MinKeepAliveSeconds	Integer	60	Minimum keep alive in seconds (> 0, < 65535).
SessionInboxSize	Integer	1000	Maximum size of session inbox (> 0, ≤ 65535).
QoS0DropOldest	Boolean	false	Whether to drop the oldest QoS 0 messages first.
RetainMessageMatchLimit	Integer	10	Limit for retained message matches (≥ 0).