[Service Bus] Make use of sendable event when sending messages

[chradek]

In the service-bus package, we perform a check to see if the sender has credits to send messages via the sendable() method:

azure-sdk-for-js/sdk/servicebus/service-bus/src/core/messageSender.ts

Line 265 in 56bd4aa

if (this._sender!.sendable()) {

If the sender isn't ready to send messages, we force a retry to give the service a chance to give us more credits:

azure-sdk-for-js/sdk/servicebus/service-bus/src/core/messageSender.ts

Lines 380 to 389 in 56bd4aa

	// let us retry to send the message after some time.
	const msg =
	`[${this._context.namespace.connectionId}] Sender "${this.name}", ` +
	`cannot send the message right now. Please try later.`;
	log.error(msg);
	const amqpError: AmqpError = {
	condition: ErrorNameConditionMapper.SenderBusyError,
	description: msg
	};
	reject(translate(amqpError));

The rhea sender emits a sendable event once more credits are allocated by the service (receiver).
https://github.com/amqp/rhea#sendable-1

Instead of throwing an error, we could attach an event listener for the sendable event and attempt to send the message if it gets triggered. We would still have a timeout that would force a retry as we do for the normal path today. This would allow us to send messages more quickly rather than waiting for the retry delay to complete before checking if the sender is sendable again.

[ramya0820]

When attempting to send over 100000 messages continuously, SenderBusyError used to get thrown repeatedly and further messages were not getting sent even when re-tried infinitely.
Thus, needed to catch this error and then re-establish the sender links such as at - https://github.com/ramya0820/azure-sdk-for-js/blob/service-bus-track-1-1.0.3/sdk/servicebus/service-bus/test/customer_issues/1389/1.0.2/send.ts

Based on this sample, the error was getting thrown at instances when total number of messages sent were 20000, 40000, 70000. These message count markers are consistent across multiple runs.

Also, the MaxListenersExceededWarning is showing up as well - so in case we are working on updating the implementation to use the new AwaitableSender, that might potentially help resolve multiple issues at once.

[github-actions]

Hi @chradek, we deeply appreciate your input into this project. Regrettably, this issue has remained inactive for over 2 years, leading us to the decision to close it. We've implemented this policy to maintain the relevance of our issue queue and facilitate easier navigation for new contributors. If you still believe this topic requires attention, please feel free to create a new issue, referencing this one. Thank you for your understanding and ongoing support.