Thanks Guozhang， Most params are not set in our config . So max retries should be 3 by default
In your explanation: a. msg1 sent, produce() returned. b. msg2 sent. c. msg1 failed, and retried. d. msg2 acked. e. msg1 acked. But is acks is 0, "the retries configuration will not take effect (as the client won't generally know of any failures). " And I find in new producer to be released acks default value is already changed to 1. If acks is set to 1, the order will be maintained even they are sent from different producers? 2015-11-24 2:47 GMT+08:00 Guozhang Wang <wangg...@gmail.com>: > Yonghui, > > With ack = 0 and retries > 0 this could happen since producer.send() > returns before it gets acked from the broker, so you could get the > following trace: > > a. msg1 sent, produce() returned. > b. msg2 sent. > c. msg1 failed, and retried. > d. msg2 acked. > e. msg1 acked. > > Assuming you said "msg1 and msg2 may notbe sent by one producer", out of > ordering can even happen more likely as they could arrive to the broker > from different sockets at arbitrary ordering. > > Guozhang > > On Mon, Nov 23, 2015 at 4:31 AM, Yonghui Zhao <zhaoyong...@gmail.com> > wrote: > > > The ack mode is default value 0. > > > > > > - 0, which means that the producer never waits for an acknowledgement > > from the broker (the same behavior as 0.7). This option provides the > > lowest > > latency but the weakest durability guarantees (some data will be lost > > when > > a server fails). > > > > And msg1 and msg2 may not be sent by one broker. > > > > > > 2015-11-21 7:56 GMT+08:00 Guozhang Wang <wangg...@gmail.com>: > > > > > Yonghui, > > > > > > What is the ack mode for the producer clients? And are msg1 and msg2 > sent > > > by the same producer? > > > > > > Guozhang > > > > > > On Thu, Nov 19, 2015 at 10:59 PM, Yonghui Zhao <zhaoyong...@gmail.com> > > > wrote: > > > > > > > Broker setting is: 8 partitions, 1 replica, kafka version 0.8.1 > > > > > > > > We send 2 message at almost same time. > > > > > > > > Msg1 first, Msg2 second. > > > > > > > > We have more than 1 producers in sync mode. > > > > > > > > We may send msg1 in one broker, after *producer.send return response* > > > > And send msg2 in the other broker. > > > > > > > > Both 2 msg has same partition key. > > > > > > > > In consumer side, we find the 2 msg is in same partition as expected, > > > but > > > > the order is inverted as msg2, msg1. > > > > > > > > Is it possible for kafka? > > > > > > > > > > > > > > > > -- > > > -- Guozhang > > > > > > > > > -- > -- Guozhang >
