Pubsub

Publish and subscribe

StreamingPull - https://cloud.google.com/pubsub/docs/pull#streamingpull_dealing_with_large_backlogs_of_small_messages - if the input streams in bursts.

Points about Pubsub

1. Publisher application send messages to topic.

2. A publisher application sends messages to pubsub service. The message has been received by the subscriber. And an acknowledgement is sent back to the pubsub service. Now the message will be removed from the queue of subscriber service.