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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 the Google Cloud Pub/Sub C++ client library, spanning versions from 2.11.0 to the latest release candidate 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eMessage ordering in the Pub/Sub client library is disabled by default to maximize throughput for applications that do not require ordered message delivery.\u003c/p\u003e\n"],["\u003cp\u003eWhen message ordering is enabled, the client library ensures that messages are delivered in the same order they are sent by waiting for the successful delivery of each message batch before sending the next one.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eMessageOrderingOption\u003c/code\u003e is a boolean type that controls whether this message ordering behavior is enabled, and you can find more information regarding it in the documentation for the \u003ccode\u003ePublisher\u003c/code\u003e class.\u003c/p\u003e\n"]]],[],null,[]]
