After a publisher flushes a batch of messages the batch is (obviously) not received immediately by the service. While the batch remains pending it potentially consumes memory resources in the client (and/or the service).
Some applications may have constraints on the number of bytes and/or messages they can tolerate in this pending state, and may prefer to block or reject messages.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-03-14 UTC."],[[["The content provides a list of C++ Pub/Sub library versions, ranging from the latest release candidate `2.37.0-rc` down to version `2.11.0`."],["Each version listed links to documentation for the `MaxPendingMessagesOption` struct within that specific release."],["`MaxPendingMessagesOption` controls the maximum number of messages a publisher can have pending, and this limits the amount of memory that pending messages consume in the client and service."],["The `MaxPendingMessagesOption` type is an alias of `std::size_t`, an unsigned integer type."]]],[]]