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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 page provides documentation for different versions of the \u003ccode\u003eMessageOrderingOption\u003c/code\u003e in the Google Cloud Pub/Sub C++ library, ranging from version 2.11.0 to the latest release candidate 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eMessage ordering, which ensures messages are received in the same order they were published, is a feature that can be enabled, but is disabled by default to maintain maximum throughput.\u003c/p\u003e\n"],["\u003cp\u003eWhen message ordering is enabled, the client library waits for a batch of messages to be successfully delivered before sending the next batch.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation page has a specific \u003ccode\u003ePublisher\u003c/code\u003e class which can be found in the links provided, and contains more information on message ordering.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003eMessageOrderingOption\u003c/code\u003e is an alias for the \u003ccode\u003ebool\u003c/code\u003e type in the library.\u003c/p\u003e\n"]]],[],null,[]]
