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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-07 UTC."],[[["The webpage provides documentation for the `MaxPendingMessagesOption` struct within the Google Cloud Pub/Sub C++ library, specifically detailing its functionality across various versions."],["The latest release candidate version is 2.37.0-rc, and the page also links to documentation for all versions dating back to 2.11.0."],["`MaxPendingMessagesOption` controls the maximum number of messages that can be pending acknowledgement from the Pub/Sub service, before blocking or rejecting further messages."],["The `MaxPendingMessagesOption` is an alias of `std::size_t`, used for managing the memory resources in the client while waiting for a batch of messages to be received."]]],[]]
