mirror of
https://github.com/prometheus/prometheus.git
synced 2025-09-21 22:01:01 +02:00
3f59fe1a80
* test(chunkenc): appending histograms with empty buckets and gaps Append such native histograms that have empty buckets and gaps between the indexes of those buckets. There is a special case for appending counter native histograms to a chunk in TSDB: if we append a histogram that is missing some buckets that are already in chunk, then usually that's a counter reset. However if the missing bucket is empty, meaning its value is 0, then we don't consider it missing. For this case to trigger , we need to write empty buckets into the chunk. Normally native histograms are compacted when we emit them , so this is very rare and compact make sure that there are no multiple continuous empty buckets with gaps between them. The code that I've added in #14513 did not take into account that you can bypass compact and write histograms with many empty buckets, with gaps between them. These are still valid, so the code has to account for them. Main fix in the expandIntSpansAndBuckets and expandFloatSpansAndBuckets function. I've also refactored them for clarity. Consequently needed to fix insert and adjustForInserts to also allow gaps between inserts. I've added some new test cases (data driven test would be nice here, too many cases). And removed the deprecated old function that didn't deal with empty buckets at all. Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com> Signed-off-by: George Krajcsovits <krajorama@users.noreply.github.com> Co-authored-by: Björn Rabenstein <beorn@grafana.com>
TSDB
This directory contains the Prometheus TSDB (Time Series DataBase) library, which handles storage and querying of all Prometheus v2 data.
Documentation
External resources
- A writeup of the original design can be found here.
- Video: Storing 16 Bytes at Scale from PromCon 2017.
- Compression is based on the Gorilla TSDB white paper.
A series of blog posts explaining different components of TSDB: