[PubSub] Failed precondition when using ordering key.

[okkero]

Seems like Publisher doesn't batch messages correctly based on ordering key. When calling .publish(...) multiple times with different ordering keys I get the following error: Status { code: FailedPrecondition, message: "In a single publish request, all messages must have no ordering key or they must all have the same ordering key. [code=539b]", source: None }

Per the Publisher documentation it looks like it is supposed to be able to handle different ordering keys just fine: "Each item is added with a given key. Items added to the empty string key are handled in random order. Items added to any other key are handled sequentially."

I don't know if this is a documentation issue or an implementation issue, but at least I could not find anything in the documentation stating that multiple different ordering keys is not supported by a single Publisher. I guess the workaround for now would be to use one Publisher per ordering key.

[yoshidan]

We have investigated and found that this is an implementation issue and will correct it. Although the number of requests has increased, the error can be suppressed by setting the bundle_size to 1 in the PublisherConfig, so please use this as a work-around.

 let topic = client.topic("test-topic2");
 let publisher = topic.new_publisher(Some(
        PublisherConfig {
                bundle_size: 1,
                ..Default::default()
        }
));

[okkero]

Thank you for the suggested workaround