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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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."],[[["\u003cp\u003eThis webpage provides a reference for the \u003ccode\u003eMaxPendingMessagesOption\u003c/code\u003e in the Google Cloud Pub/Sub C++ library, with version 2.37.0-rc being the latest.\u003c/p\u003e\n"],["\u003cp\u003eThe content includes documentation for various versions of the library, ranging from 2.11.0 up to the latest 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003eMaxPendingMessagesOption\u003c/code\u003e manages the maximum number of messages that can be pending, potentially consuming memory resources, after a publisher flushes a batch.\u003c/p\u003e\n"],["\u003cp\u003eThis option helps applications with memory or message constraints to manage and, if needed, reject messages in a pending state.\u003c/p\u003e\n"],["\u003cp\u003eThe type alias for \u003ccode\u003eMaxPendingMessagesOption\u003c/code\u003e is \u003ccode\u003estd::size_t\u003c/code\u003e, indicating it deals with the size or number of messages.\u003c/p\u003e\n"]]],[],null,[]]
