Hi,
I read the documentation about upgrading
Kafka(http://kafka.apache.org/21/documentation.html#upgrade_2_1_0) but I have
questions that I believe the documentation doesn't cover. I am planning to
upgrade Kafka from 2.0.0 to 2.1.0 and would like to make sure what to do when
something goes wrong - I am mostly interested in reverting back to the older
version. I admit that I am confused about API versions, log message versions
and inter broker protocol versions.
According to the documentation these are the steps I need to follow:
1. Set inter.broker.protocol.version to 2.0.0
2. I don't have currently log.message.format.version set to 2.0.0, so
according to documentation I don't need to specify it
3. Upgrade broker code and restart it. This is I am not sure what happens
next. Since I don't have log.message.format.version set then broker's default
value will be used - I guess 2.1.1. Does it mean that:
* New messages that arrive from producers will be saved in a log file
with a new format?
* Old messages that already exist in log files will be converted to the
new format once the broker starts?
* Does inter.broker.protocol.version has anything to do with
log.message.format.version?
I guess a) and b) are not true since according to the documentation up to this
point I can revert back to the older version of Kafka. Could you confirm?
1. Change inter.broker.protocol.version to 2.1.1 and restart brokers - after
this is done reverting back is not possible. Could you explain what is
happening in Kafka so that reverting cannot be done?
Regards,
Artur
