{"action":"created","issue":{"url":"https://api.github.com/repos/real-logic/Aeron/issues/206","repository_url":"https://api.github.com/repos/real-logic/Aeron","labels_url":"https://api.github.com/repos/real-logic/Aeron/issues/206/labels{/name}","comments_url":"https://api.github.com/repos/real-logic/Aeron/issues/206/comments","events_url":"https://api.github.com/repos/real-logic/Aeron/issues/206/events","html_url":"https://github.com/real-logic/Aeron/issues/206","id":139241882,"number":206,"title":"Handling of dropped packets","user":{"login":"republisher","id":17721826,"avatar_url":"https://avatars.githubusercontent.com/u/17721826?v=3","gravatar_id":"","url":"https://api.github.com/users/republisher","html_url":"https://github.com/republisher","followers_url":"https://api.github.com/users/republisher/followers","following_url":"https://api.github.com/users/republisher/following{/other_user}","gists_url":"https://api.github.com/users/republisher/gists{/gist_id}","starred_url":"https://api.github.com/users/republisher/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/republisher/subscriptions","organizations_url":"https://api.github.com/users/republisher/orgs","repos_url":"https://api.github.com/users/republisher/repos","events_url":"https://api.github.com/users/republisher/events{/privacy}","received_events_url":"https://api.github.com/users/republisher/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2016-03-08T10:41:08Z","updated_at":"2016-03-08T16:16:55Z","closed_at":null,"body":"I understand that when subscribers notice a gap in the sequence numbers of the received messages they can issue a NAK to the publisher to request a retransmission. However in some low-latency use-cases this may not be desirable, since the subscriber might prefer to just move on to the next message without having to wait for the retransmission to occur. Can you please clarify whether Aeron subscribers will block until the missing messages are received? Can Aeron be configured (or modified) so that it delivers the next available message to the client application without having to wait for the missing packet to arrive? Is sending the NAK mandatory or optional? Thanks"},"comment":{"url":"https://api.github.com/repos/real-logic/Aeron/issues/comments/193844707","html_url":"https://github.com/real-logic/Aeron/issues/206#issuecomment-193844707","issue_url":"https://api.github.com/repos/real-logic/Aeron/issues/206","id":193844707,"user":{"login":"tmontgomery","id":1979352,"avatar_url":"https://avatars.githubusercontent.com/u/1979352?v=3","gravatar_id":"","url":"https://api.github.com/users/tmontgomery","html_url":"https://github.com/tmontgomery","followers_url":"https://api.github.com/users/tmontgomery/followers","following_url":"https://api.github.com/users/tmontgomery/following{/other_user}","gists_url":"https://api.github.com/users/tmontgomery/gists{/gist_id}","starred_url":"https://api.github.com/users/tmontgomery/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/tmontgomery/subscriptions","organizations_url":"https://api.github.com/users/tmontgomery/orgs","repos_url":"https://api.github.com/users/tmontgomery/repos","events_url":"https://api.github.com/users/tmontgomery/events{/privacy}","received_events_url":"https://api.github.com/users/tmontgomery/received_events","type":"User","site_admin":false},"created_at":"2016-03-08T16:16:55Z","updated_at":"2016-03-08T16:16:55Z","body":"The Subscribers always deliver in order and do not skip gaps. From that perspective, retransmissions are necessary to keep a Subscriber delivering data.\r\n\r\nIn cases where loss is acceptable, a Subscriber could use the techniques in the TermGapScanner to find the end of a gap and simply skip over it and move on. Some other pieces would have to adapt, but it could be done.\r\n\r\nHowever, who use Aeron, or any transport protocol really, if loss is acceptable?\r\n"}}