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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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\u003eThis webpage provides documentation for the \u003ccode\u003eMessageOrderingOption\u003c/code\u003e in Google Cloud Pub/Sub, with a specific focus on C++ versions.\u003c/p\u003e\n"],["\u003cp\u003eThe latest version available is 2.37.0-rc, while the documentation also includes various previous versions, all the way down to version 2.11.0.\u003c/p\u003e\n"],["\u003cp\u003eMessage ordering in Pub/Sub can guarantee the sequence in which messages are received, but it can reduce throughput.\u003c/p\u003e\n"],["\u003cp\u003eThe message ordering behavior is disabled by default, and can be enabled in the \u003ccode\u003ePublisher\u003c/code\u003e class, which is documented in a separate page.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eMessageOrderingOption\u003c/code\u003e is an alias of \u003ccode\u003ebool\u003c/code\u003e.\u003c/p\u003e\n"]]],[],null,[]]
