consider range and offset in queries while looking for schema config for query sharding #7880
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…for query sharding
sandeepsukhani
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./tools/diff_coverage.sh ../loki-target-branch/test_results.txt test_results.txt ingester,distributor,querier,querier/queryrange,iter,storage,chunkenc,logql,loki Change in test coverage per package. Green indicates 0 or positive change, red indicates that test coverage for a package fell. + ingester 0%
+ distributor 0%
+ querier 0%
+ querier/queryrange 0.1%
+ iter 0%
+ storage 0%
+ chunkenc 0%
- logql -0.4%
+ loki 0% |
| return 0, 0, err | ||
| } | ||
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| if _, ok := expr.(syntax.SampleExpr); !ok { |
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Note this also changes the previous behavior of returning non-nil errors for LogSelectorExpr but now it would return nil error.
Do you think this would break anything?
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I think it is okay since previous usage was only in metric query path and range and offset are only used in metric queries.
| if r, ok := e.(*syntax.LogRange); ok && r.Interval > max { | ||
| max = r.Interval | ||
| if r, ok := e.(*syntax.LogRange); ok { | ||
| if r.Interval > maxRVDuration { |
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Q: whats the point of comparing it with maxRvDuration and maxOffset. They have only zero values right? (from the above declarations)
why not just maxRVDuration, maxOffset = r.Internval, r.Offset? Given, there can be only one LogRange expression in a given LogQL.? (can LogQL contains multiple Range expression? I doubt it though)
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you can have multiple of them with binary operations like rate({job="foo"} [1m] offset 5m) / rate({job="bar"} [1m] offset 15m)
yeah, I am working on the tests. Didn't get to work on them due to having my hand in multiple things and would like to get this PR in this week's build. Will let you know when I am done with the tests. |
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./tools/diff_coverage.sh ../loki-target-branch/test_results.txt test_results.txt ingester,distributor,querier,querier/queryrange,iter,storage,chunkenc,logql,loki Change in test coverage per package. Green indicates 0 or positive change, red indicates that test coverage for a package fell. + ingester 0%
+ distributor 0%
+ querier 0%
+ querier/queryrange 0.4%
+ iter 0%
+ storage 0%
+ chunkenc 0%
+ logql 0%
+ loki 0% |
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./tools/diff_coverage.sh ../loki-target-branch/test_results.txt test_results.txt ingester,distributor,querier,querier/queryrange,iter,storage,chunkenc,logql,loki Change in test coverage per package. Green indicates 0 or positive change, red indicates that test coverage for a package fell. + ingester 0%
+ distributor 0%
+ querier 0%
+ querier/queryrange 0.4%
+ iter 0%
+ storage 0%
+ chunkenc 0%
+ logql 0%
+ loki 0% |
…for query sharding (#7880) **What this PR does / why we need it**: We disable query sharding when a query touches multiple schema configs since they might have different sharding factors and might handle sharding differently. This check was done purely on the start and end time of the query without considering `range` and `offset`, which would change the length of the actual data being queried. Besides being incorrect, it also causes us to fail queries when migrating between tsdb and non-tsdb stores since both handle query sharding differently. For e.g., if the prev schema is `boltdb-shipper` and starting today, `tsdb` index is being used, so if we do a query `sum(rate({foo="bar"}[24h])` even with start and end within `tsdb` range, we will fail the query with error `incompatible index shard` if dynamic sharding goes with shard factor other than `32`(default shard factor in ingester for inverted index). The reason being the `range` here is `24h` which causes us to process data from previous schema as well. This PR takes care of the issue by factoring in `range` and `offset` in the queries while looking for schema config for query sharding. **Checklist** - [x] `CHANGELOG.md` updated.
What this PR does / why we need it:
We disable query sharding when a query touches multiple schema configs since they might have different sharding factors and might handle sharding differently. This check was done purely on the start and end time of the query without considering
rangeandoffset, which would change the length of the actual data being queried.Besides being incorrect, it also causes us to fail queries when migrating between tsdb and non-tsdb stores since both handle query sharding differently. For e.g., if the prev schema is
boltdb-shipperand starting today,tsdbindex is being used, so if we do a querysum(rate({foo="bar"}[24h])even with start and end withintsdbrange, we will fail the query with errorincompatible index shardif dynamic sharding goes with shard factor other than32(default shard factor in ingester for inverted index). The reason being therangehere is24hwhich causes us to process data from previous schema as well.This PR takes care of the issue by factoring in
rangeandoffsetin the queries while looking for schema config for query sharding.Checklist
CHANGELOG.mdupdated