Using a predeclared exchange that does not exist creates it

[gvmw]

Running the following command creates an exchange:

make run ARGS="--producers 1 --rate 1 --consumers 0 --exchange idonotexist --predeclared true"

Since this exchange does not exist, it should not be created since we use the --predeclared true flag.

[acogoluegnes]

Oh boy, this goes back to fc02da2.

[acogoluegnes]

So this is the condition:

if (!predeclared || !exchangeExists(connection, exchangeName)) {
  channel.exchangeDeclare(exchangeName, exchangeType);
  topologyRecording.recordExchange(exchangeName, exchangeType);
}

It's been there since the beginning of time, it's been changed, reverted, etc. I don't really know what's the best thing to do here :)

[acogoluegnes]

So you're in the case when predeclared is true but the exchange does not exist, so PerfTest sees the exchange does not exists and creates it for you, how nice and paternalistic of it.

This is surprising, but we're telling PerfTest to publish to something that does not exist, is it really what we want?

[michaelklishin]

Arguably --predeclared should mean that at least for exchanges (the less dynamic part of the topology in practice), nothing is declared. I can see how this won't be constructive for queues and consumers, in particular since a single flag
can control the behavior of both producer and consumer sides.

[acogoluegnes]

So you're suggesting that PerfTest should never create exchanges when --predeclared is set to true?