Logstash dont start if output fail

Using RabbitMQ as output, Logstash dont start if RabbitMQ is down:

[2020-10-08T14:45:32,102][ERROR][logstash.outputs.rabbitmq][main] RabbitMQ connection error, will retry. {:error_message=>"Connection was refused. Target host list: datahub-hot-rabbitmq:5672, target virtual host: /, username: guest", :exception=>"MarchHare::ConnectionRefused"}

Is it possible to start logstash anyway, then event could queue?

My use case:

We use logstash as HTTP service, on kubernetes, as Service/Ingress, to send events to RabbitMQ, sometime RabbitMQ is down, but I would like Logstash always up, and accept HTTP connections.

(Then, when RabbitMQ is up, logstash logs:

[2020-10-08T14:55:05,692][INFO ][logstash.outputs.rabbitmq][main] Connected to RabbitMQ at
[2020-10-08T14:55:05,928][INFO ][logstash.javapipeline    ][main] Starting pipeline {:pipeline_id=>"main", "pipeline.workers"=>1, "pipeline.batch.size"=>125, "pipeline.batch.delay"=>50, "pipeline.max_inflight"=>125, "pipeline.sources"=>["/usr/share/logstash/pipeline/logstash.conf"], :thread=>"#<Thread:0x20d4b737 run>"}
[2020-10-08T14:55:06,819][INFO ][logstash.javapipeline    ][main] Pipeline Java execution initialization time {"seconds"=>0.89}
[2020-10-08T14:55:06,923][INFO ][logstash.javapipeline    ][main] Pipeline started {"pipeline.id"=>"main"}
[2020-10-08T14:55:06,936][INFO ][logstash.inputs.http     ][main][4f906e017895aa9eaf664da2c6d2e5e882bd314ad4555d292d5e53c9fa053cd6] Starting http input listener {:address=>"0.0.0.0:8080", :ssl=>"false"}
[2020-10-08T14:55:07,008][INFO ][logstash.agent           ] Pipelines running {:count=>1, :running_pipelines=>[:main], :non_running_pipelines=>[]}
[2020-10-08T14:55:07,275][INFO ][logstash.agent           ] Successfully started Logstash API endpoint {:port=>9600}