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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 page provides a list of different versions of the \u003ccode\u003eMessageOrderingOption\u003c/code\u003e for the Google Cloud Pub/Sub C++ client library, with version 2.37.0-rc being the latest release candidate.\u003c/p\u003e\n"],["\u003cp\u003eThe default behavior for message ordering in the \u003ccode\u003ePublisher\u003c/code\u003e class is disabled to maximize throughput, as guaranteeing order requires waiting for each batch to be delivered successfully.\u003c/p\u003e\n"],["\u003cp\u003eThe page references the \u003ccode\u003ePublisher\u003c/code\u003e class documentation, providing information regarding the implications and usage of message ordering, which is to ensure messages are received in the order they were sent.\u003c/p\u003e\n"],["\u003cp\u003eThe page states that the \u003ccode\u003eMessageOrderingOption\u003c/code\u003e is a type alias of \u003ccode\u003ebool\u003c/code\u003e.\u003c/p\u003e\n"]]],[],null,[]]
