Understanding the max.inflight property of kafka producer
Your use case is slightly unclear. You mention ordering and no data loss but don't specify if you tolerate duplicate messages. So it's unclear if you want At least Once (QoS 1) or Exactly Once
Either way, as you're using 1.0.0 and only using a single partition, you should have a look at the Idempotent Producer instead of tweaking the Producer configs. It allows to properly and efficiently guarantee ordering and no data loss.
From the documentation:
Idempotent delivery ensures that messages are delivered exactly once to a particular topic partition during the lifetime of a single producer.
The early Idempotent Producer was forcing max.in.flight.requests.per.connection to 1 (for the same reasons you mentioned) but in the latest releases it can now be used with max.in.flight.requests.per.connection set to up to 5 and still keep its guarantees.
Using the Idempotent Producer you'll not only get stronger delivery semantics (Exactly Once instead of At least Once) but it might even perform better!
I recommend you check the delivery semantics [in the docs] [in the docs]:http://kafka.apache.org/documentation/#semantics
Back to your question
Yes without the idempotent (or transactional) producer, if you want to avoid data loss (QoS 1) and preserve ordering, you have to set max.in.flight.requests.per.connection to 1, allow retries and use acks=all. As you saw this comes at a significant performance cost.
Yes, you must set the max.in.flight.requests.per.connection property to 1.
In the article you have read it was an initial mistake (currently corrected) where author wrote:
max.in.flights.requests.per.session
which doesn't exist in the Kafka documentation.
This errata comes probably from the book "Kafka The Definitive Guide" (1st edition) where you can read in the page 52:
<...so if guaranteeing order is critical, we recommend setting
in.flight.requests.per.session=1to make sure that while a batch of messages is retrying, additional messages will not be sent ...>