AMQP Appender pending message count - spring

Question

We are sending audit log messages to a RabbitMQ cluster which is sometimes unavailable for reasons we cannot influence.
When the queue is not available, log messages start to accumulate locally and we get a out-of-memory eventually on the client.
We are using a AMQP Appender to submit our messages.
Is there a way we can query the count of pending log messages and raise an alert when messages start adding up?

Answer 1

Well, it isn't possible. There is just no any hooks to do that.
You can consider, though, to decrease maxSenderRetries from default 30 to 1 or 2. After that you'll start to lose log messages:
int retries = event.incrementRetries();
if (retries < AmqpAppender.this.maxSenderRetries) {
// Schedule a retry based on the number of times I've tried to re-send this
AmqpAppender.this.retryTimer.schedule(new TimerTask() {
#Override
public void run() {
AmqpAppender.this.events.add(event);
}
}, (long) (Math.pow(retries, Math.log(retries)) * 1000));
}
else {
addError("Could not send log message " + logEvent.getMessage()
+ " after " + AmqpAppender.this.maxSenderRetries + " retries", e);
}
We might have to expose queueSize option instead of default:
public LinkedBlockingQueue() {
this(Integer.MAX_VALUE);
}
Feel free to raise a JIRA on the matter.