Guaranteed Message Queuing Limits

The maximum number of Guaranteed messages that Solace PubSub+ event brokers can queue at one time for delivery will be cumulatively reduced by the following factors:

• the number of messages that provisioned endpoints receive—If a single published message is queued for delivery on n endpoints, that counts as n messages queued for delivery, even though only one copy of the message is stored in either the ADB or external disk storage array.
• whether data from the event broker is being replicated—When the Replication facility is used, a copy of a message in the Replication queue counts as another message queued for delivery. That is, if a message is queued for delivery on n endpoints, and it is to be replicated, that counts as n +1 messages queued for delivery.
• whether the event broker is processing transactions—When transactions are used, the event broker has to maintain extra information for each message in a transaction until the transaction is committed or rolled back.
• whether there are provisioned endpoints configured to respect published messages’ TTL expiry times—When an endpoint respects a message’s TTL, the TTL is recorded and maintained until the message is consumed or discarded.