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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-07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 latest version available is 2.37.0-rc, which represents a release candidate version of the software."],["This page provides access to documentation for multiple versions of the software, ranging from 2.11.0 up to the latest release candidate."],["The documentation on this page specifically covers `MaxPendingBytesOption`, which relates to setting constraints on pending message size within the `google::cloud::pubsub` namespace."],["`MaxPendingBytesOption` is a configuration option to manage the maximum number of bytes a user is willing to tolerate in a pending state in memory."],["The `MaxPendingBytesOption` is an alias of the `std::size_t` data type."]]],[]]
