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 detailed list of Google Cloud Pub/Sub C++ client library versions, ranging from the release candidate 2.37.0-rc down to version 2.11.0."],["Each version number in the list links to documentation for the `MaxPendingMessagesOption` struct, which controls the maximum number of messages that can be pending in the client."],["The `MaxPendingMessagesOption` struct relates to managing resource usage by limiting the number of messages waiting to be processed by the service after a batch is flushed by a publisher."],["The `MaxPendingMessagesOption` struct is a type alias of `std::size_t`, indicating that it is an unsigned integer type suitable for representing sizes and counts."]]],[]]