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"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[[["This webpage provides a detailed list of Google Cloud Pub/Sub C++ client library versions, ranging from version 2.11.0 up to the latest release candidate 2.37.0-rc."],["Each version listed links to the documentation for `MaxPendingMessagesOption`, a feature related to managing memory usage and message flow."],["The `MaxPendingMessagesOption` setting controls the maximum number of messages allowed to be pending, thus helping manage memory resources on the client-side."],["The option for `MaxPendingMessages` is an alias of `std::size_t`, a type used for representing sizes or counts."]]],[]]
