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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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."],[[["The latest version available is 2.37.0-rc, which can be accessed via the provided link."],["The webpage provides a list of version-specific documentation for `MaxPendingMessagesOption` within the Google Cloud Pub/Sub C++ library, spanning from version 2.11.0 to the most current release candidate version."],["`MaxPendingMessagesOption` defines the maximum number of messages that can be pending during publishing and consuming, which can affect memory usage."],["This option is important for applications that need to control memory consumption related to pending messages, especially as it relates to batching and flushing."],["The type alias for `MaxPendingMessagesOption` is defined as `std::size_t`, indicating it's an unsigned integer representing the size of pending messages."]]],[]]
