BUGFIX: TSDB: panic in query during truncation with OOO head #14831
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Regression test for prometheus#14822 Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
krajorama
force-pushed
the
fix-panic-in-ooo-query
branch
from
a113fe7
to
d102c99
Compare
krajorama
added a commit
that referenced
this pull request
Sep 5, 2024
Ref: #14831 Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
krajorama
force-pushed
the
fix-panic-in-ooo-query
branch
from
c754ab5
to
247ed00
Compare
Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
krajorama
force-pushed
the
fix-panic-in-ooo-query
branch
2 times, most recently
from
356e519
to
8a39690
Compare
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
krajorama
force-pushed
the
fix-panic-in-ooo-query
branch
from
8a39690
to
03e1ac1
Compare
bboreham
reviewed
Sep 5, 2024
tsdb/ooo_head_read.go
Outdated
| @@ -513,7 +513,7 @@ type HeadAndOOOQuerier struct { | |||
| head *Head | |||
| index IndexReader | |||
| chunkr ChunkReader | |||
| querier storage.Querier | |||
| querier storage.Querier // This might be nil if head was truncated. | |||
There was a problem hiding this comment.
Generally I advise to state what the thing means, not when you expect it to apply.
So "If nil, do not read from in-order head"?
Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
|
cc PTAL @colega |
jesusvazquez
approved these changes
Sep 5, 2024
bboreham
approved these changes
Sep 5, 2024
krajorama
added a commit
to krajorama/prometheus
that referenced
this pull request
Sep 9, 2024
Followup to prometheus#14831 Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Added regression test for #14822. Doesn't cause segfault before #14354
The segfault was due to a race condition between query start and compaction.
When compaction starts, in-order queries may overlap with the TSDB head, but also might fall into the truncated time of the head. In such case, the head querier
headQuerieris nil in db.go hereprometheus/tsdb/db.go
Line 2062 in 1e01e97
and
prometheus/tsdb/db.go
Line 2137 in 1e01e97
That pointer is not used for selecting samples, but is referenced in
Close()which causes the segfault.The fix essentially restores the original function where we did not rely on the headQuerier in creating the OOO head querier:
prometheus/tsdb/db.go
Line 2157 in 9849418