In your case, you need to restart B2 with unclean.leader.election=true. This will enable B2 to become leader with 90 messages.
On Thu, Jun 28, 2018 at 11:51 PM Jordan Pilat <jrpi...@gmail.com> wrote: > If I restart the broker, won't that cause all 100 messages to be lost? > > On 2018/06/28 02:59:15, Manikumar <manikumar.re...@gmail.com> wrote: > > You can enable unclean.leader.election temporarily for specific topic by > > using kafka-topics.sh command. > > This requires broker restart to take effect. > > > > http://kafka.apache.org/documentation/#topicconfigs > > > > On Thu, Jun 28, 2018 at 2:27 AM Jordan Pilat <jrpi...@gmail.com> wrote: > > > > > Heya, > > > > > > I had a question about what behavior to expect from a particular > > > scenario. Given: > > > A. Unclean leader elections are disabled > > > B. A partition is led by Broker1 and followed by Broker2 > > > C. Broker1 is on offset 100 > > > D. Broker2 is on offset 90 > > > E. Broker2 has fallen out of the ISR, leaving only Broker1 in the ISR > > > F. Broker1 has a hard drive failure and goes down. All messages for > the > > > partition in question are permanently lost. > > > > > > _As I understand it_, the only way for the partition to come back > online > > > is to bring Broker1 back online, and suffer the loss of 100 messages > (as > > > Broker2's log will be truncated to Broker1's offset, which will start > from > > > scratch due to the hard drive loss) > > > > > > Is there a procedure in such a case, to force-elect Broker2 the leader, > > > and thus only lose 10 messages? > > > > > > Thanks! > > > - Jordan Pilat > > > > > >
