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 documents various versions of the `MaxPendingMessagesOption` for the Google Cloud Pub/Sub C++ client library."],["The latest version documented is 2.37.0-rc, while the page also includes documentation for versions ranging from 2.36.0 down to 2.11.0."],["`MaxPendingMessagesOption` relates to managing the number of messages that can be in a pending state after being sent but not yet received, which impacts memory usage."],["This option is configurable with `std::size_t` type, giving the user control over memory consumption."]]],[]]
