{"action":"created","issue":{"url":"https://api.github.com/repos/edenhill/librdkafka/issues/428","labels_url":"https://api.github.com/repos/edenhill/librdkafka/issues/428/labels{/name}","comments_url":"https://api.github.com/repos/edenhill/librdkafka/issues/428/comments","events_url":"https://api.github.com/repos/edenhill/librdkafka/issues/428/events","html_url":"https://github.com/edenhill/librdkafka/issues/428","id":117642586,"number":428,"title":"A question about  \"How to decrease message latency\" ","user":{"login":"jimmy1911","id":2586763,"avatar_url":"https://avatars.githubusercontent.com/u/2586763?v=3","gravatar_id":"","url":"https://api.github.com/users/jimmy1911","html_url":"https://github.com/jimmy1911","followers_url":"https://api.github.com/users/jimmy1911/followers","following_url":"https://api.github.com/users/jimmy1911/following{/other_user}","gists_url":"https://api.github.com/users/jimmy1911/gists{/gist_id}","starred_url":"https://api.github.com/users/jimmy1911/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jimmy1911/subscriptions","organizations_url":"https://api.github.com/users/jimmy1911/orgs","repos_url":"https://api.github.com/users/jimmy1911/repos","events_url":"https://api.github.com/users/jimmy1911/events{/privacy}","received_events_url":"https://api.github.com/users/jimmy1911/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":10,"created_at":"2015-11-18T17:52:02Z","updated_at":"2015-11-19T08:22:23Z","closed_at":null,"body":"hi, edenhill \r\n    I read the wiki https://github.com/edenhill/librdkafka/wiki/How-to-decrease-message-latency and try to do some test. In my test senario, there is a producer with following config : \r\n    \"queue.buffering.max.messages\", \"500000\"\r\n    \"queue.buffering.max.ms\", \"1\"\r\n    \"batch.num.messages\", \"1\" \r\n    \"message.send.max.retries\", \"3\"\r\n    \"retry.backoff.ms\", \"500\"\r\nand a consumer with  following config : \r\n    \"queued.min.messages\", \"1000000\"\r\n   \"fetch.wait.max.ms\", \"10\"\r\n    \"fetch.error.backoff.ms\", \"5\"\r\n    \"event_cb\", &ex_event_cb\r\nStep1:\r\n    start consumer to consume a new topic which have no message(consume timeout is set 50ms).\r\nStep2:\r\n    start producer to produce 1000 message(size 2000bytes) with a timestamp.\r\nStep3:\r\n    consumer  starts to consume message, and calculate the latency with  timestamp in message.\r\nBefore the 91st message, the avg latency is 13ms.After that there occured 20 consume TIME_OUT which makes 1000ms more latency.So the 92nd message's latency is about 1024ms. No mater how to set the consume timeout, the latency will be more than 1000ms.\r\n    How to config producer and consumer to decrease the latency in this case?\r\n\r\n\r\n"},"comment":{"url":"https://api.github.com/repos/edenhill/librdkafka/issues/comments/157987019","html_url":"https://github.com/edenhill/librdkafka/issues/428#issuecomment-157987019","issue_url":"https://api.github.com/repos/edenhill/librdkafka/issues/428","id":157987019,"user":{"login":"edenhill","id":524990,"avatar_url":"https://avatars.githubusercontent.com/u/524990?v=3","gravatar_id":"","url":"https://api.github.com/users/edenhill","html_url":"https://github.com/edenhill","followers_url":"https://api.github.com/users/edenhill/followers","following_url":"https://api.github.com/users/edenhill/following{/other_user}","gists_url":"https://api.github.com/users/edenhill/gists{/gist_id}","starred_url":"https://api.github.com/users/edenhill/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/edenhill/subscriptions","organizations_url":"https://api.github.com/users/edenhill/orgs","repos_url":"https://api.github.com/users/edenhill/repos","events_url":"https://api.github.com/users/edenhill/events{/privacy}","received_events_url":"https://api.github.com/users/edenhill/received_events","type":"User","site_admin":false},"created_at":"2015-11-19T08:22:23Z","updated_at":"2015-11-19T08:22:23Z","body":"What is your request.required.acks setting?\r\nThe higher replication the higher latency. E.g, compare 1 (just leader) to -1  (all ISR)"}}