Yes, the default ack is currently 0. Let me explain the ack mode a bit more
so that we are on the same page (details are covered in my ApachCon
) . There
are only 3 ack modes that make sense.
ack=0: producer waits until the message is in the producer's socket buffer
ack=1: producer waits until the message is received by the leader
ack=-1: producer waits until the message is committed
The tradeoffs are:
ack=0: lowest latency; some data loss during broker failure
ack=1: lower latency; a few data loss during broker failure
ack=-1: low latency; no data loss during broker failure
All cases work with replication factor 1, which is the default setting out
of box. With ack=1/-1, the producer may see some error when the leader
hasn't been being elected. However, the number of errors should be small
since typically leaders are elected very quickly.
The argument for making the default ack 0 is that (1) this is the same
behavior you get in 0.7 and (2) the producer runs fastest in this mode.
The argument for making the default ack 1 or -1 is that they gave you
I am not sure what's the best thing to do that here since correct setting
really depends on the application. What do people feel?
On Tue, Mar 5, 2013 at 6:36 AM, Joe Stein <[EMAIL PROTECTED]> wrote: