title: Google Pubsub vs Kafka comparison on the restart of pipeline
body: <p>I am trying to write an ingestion application on GCP by using Apache Beam.I should write it in a streaming way to read data from Kafka or pubsub topics and then ingest to datasource.</p>
  
  <p>while it seems straight forward to write it with pubsub and apache beam but my question is what would happen if my ingestion fails or to be restarted and if it again reads all data from the start of pubsub topic or like kafka it can read from latest committed offsets in the topic?</p>