> Since we don't have infinite space, we can expect eventually to lose some messages in this scenario.
Sure, that's technically correct but applies to basically everything. It is very likely your users/orders/whatever table in your database is also "trending to infinity" over time, except this doesn't mean databases should always be empty or that we should expect to eventually lose some users/orders/whatever.
Or, more succinctly, if your queue capacity is 10 million messages and your queue messages represent "houses purchased through our website", then in reality your queue capacity is infinite because nobody will ever purchase 10 million homes through your application per small unit of time.
Your response is correct, but there's a more fundamental flaw in the preceding comment: although both paragraphs are true in isolation, the implication between them is false. "The queue is _currently_ trending to infinity" does not imply "The queue will _continue_ to monotonically trend to infinity". Periodicity is commonplace in real-life situations; and while parts of Queueing Theory produces some insightful and helpful insights by ignoring it, care should be taken when applying them.
Sure, that's technically correct but applies to basically everything. It is very likely your users/orders/whatever table in your database is also "trending to infinity" over time, except this doesn't mean databases should always be empty or that we should expect to eventually lose some users/orders/whatever.
Or, more succinctly, if your queue capacity is 10 million messages and your queue messages represent "houses purchased through our website", then in reality your queue capacity is infinite because nobody will ever purchase 10 million homes through your application per small unit of time.