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."],[[["This webpage lists various versions of the `MaxPendingMessagesOption` for the Google Cloud Pub/Sub C++ client library, ranging from version 2.11.0 to the latest release candidate 2.37.0-rc."],["The `MaxPendingMessagesOption` controls the maximum number of messages that can be pending after a publisher flushes a batch, which can help manage memory consumption."],["The content also describes that while messages remain in a pending state, they will potentially consume memory resources in the client and/or the service, which may cause some applications to block or reject messages."],["`MaxPendingMessagesOption` is a type alias of `std::size_t`, indicating it uses standard size type for handling the pending message count."]]],[]]