To guarantee messages are received by the service in the same order that the application gives them to a publisher, the client library needs to wait until a batch of messages is successfully delivered before sending the next batch, otherwise batches may arrive out of order as there is no guarantee the same channel or network path is used for each batch.
For applications that do not care about message ordering, this can limit the throughput. Therefore, the behavior is disabled by default.
See Also
the documentation for the Publisher class for details.
[[["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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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\u003eThe latest version available is 2.37.0-rc, with numerous other versions, down to 2.11.0, also listed.\u003c/p\u003e\n"],["\u003cp\u003eThis document details the \u003ccode\u003eMessageOrderingOption\u003c/code\u003e struct within the Google Cloud Pub/Sub C++ library, with versioning support.\u003c/p\u003e\n"],["\u003cp\u003eMessage ordering in Pub/Sub guarantees that messages are received in the order they were sent, but this feature is disabled by default as it can limit throughput for those who don't need it.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003ePublisher\u003c/code\u003e class documentation provides additional information on message ordering.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eMessageOrderingOption\u003c/code\u003e is a type alias that represents a boolean value.\u003c/p\u003e\n"]]],[],null,[]]
