The partition chart
I made you a chart. I make a lot of charts.
A hot partition looks like a slow consumer from the outside. The chart at the top of a topic shows what it looks like from the inside: how the retained messages are spread over the partitions.
What it shows
- The partition holding most of the messages, with its share.
- Partitions holding none while their neighbors are full.
- Which key dominates, estimated from the messages read and weighted by each partition's depth, so a hot partition cannot hide the key that made it hot.
The chart counts what is retained now. Retention and compaction change that, so it is not a record of what was produced. The chart says so under it.
When it refuses
| Refuses when | Says |
|---|---|
| The topic has no partitions, or only one | Nothing to compare |
| Too few messages per partition to carry a proportion | Too few to judge |
| No keys, or too small a sample | No key estimate |
14 messages over 3 partitions are not enough to have an opinion about distribution, and Marshall will not pretend otherwise.
Lily says I over-explain. Lily is right, but look at this partition.