sql: do not consider TCL stmts in sql stats tracing #138041
Merged
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
![blathers[crl]](https://avatars.githubusercontent.com/in/59700?s=40&u=373d9101a12edc3847d2fb6ae78e3adcfb4ca41e&v=4){kind=avatar}
|
It looks like your PR touches production code but doesn't add or edit any test code. Did you consider adding tests to your PR? 🦉 Hoot! I am a Blathers, a bot for CockroachDB. My owner is dev-inf. |
|
This change is |
xinhaoz
force-pushed
the
disable-sampling-tcl
branch
4 times, most recently
from
443406e to
6da47a8
Compare
xinhaoz
requested review from
a team and
kyle-a-wong
and removed request for
a team
kyle-a-wong
approved these changes
Jan 3, 2025
pkg/sql/instrumentation_test.go
Outdated
| @@ -251,10 +252,11 @@ func TestSampledStatsCollectionOnNewFingerprint(t *testing.T) { | |||
|
|
|||
| require.Equal(t, len(queries), len(collectedTxnStats)) | |||
|
|
|||
| // We should have collected stats for each of the queries. | |||
| for i := range collectedTxnStats { | |||
| // We should have collected stats for each of the first 4 queries. | |||
There was a problem hiding this comment.
nit: maybe change this to "each of the queries, except the last" or something, since more queries could be added in the future
For SQL stats we trace every new fingerprint in an application container in order to populate statistics that are only available via tracing for each fingerprint. This sampling logic worked by tracking the SQL fingerprint strings encountered by each application but did not factor in fingerprints that are not tracked by SQL stats, such as TCL statements (BEGIN, COMMIT, ROLLBACK), were being treated as new fingerprints on each execution which resulted in tracing being turned on. This commit ensures that we don't consider TCL statements in this sampling strategy. TestSampledStatsCollectionOnNewFingerprint is also fixed as it was assuming that previously seen statements in new transactions would trigger this sampling behaviour when it should not - this was being erronneously triggered by `BEGIN`. ``` name old time/op new time/op delta Sysbench/SQL/3node/oltp_read_write-10 5.61ms ± 3% 5.69ms ± 4% ~ (p=0.167 n=8+9) name old alloc/op new alloc/op delta Sysbench/SQL/3node/oltp_read_write-10 2.15MB ± 2% 2.12MB ± 2% -1.24% (p=0.029 n=10+10) name old allocs/op new allocs/op delta Sysbench/SQL/3node/oltp_read_write-10 10.7k ± 1% 10.5k ± 0% -1.69% (p=0.000 n=10+9) ``` Epic: none Part of: cockroachdb#133307 Release note: None
xinhaoz
force-pushed
the
disable-sampling-tcl
branch
from
6da47a8 to
8f86503
Compare
|
TFTR! |
|
Nice, thank you! |
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.
For SQL stats we trace every new fingerprint in an application
container in order to populate statistics that are only available
via tracing for each fingerprint. This sampling logic worked by
tracking the SQL fingerprint strings encountered by each application
but did not factor in fingerprints that are not tracked by SQL stats,
such as TCL statements (BEGIN, COMMIT, ROLLBACK), were being treated
as new fingerprints on each execution which resulted in tracing being
turned on. This commit ensures that we don't consider TCL statements
in this sampling strategy. TestSampledStatsCollectionOnNewFingerprint
is also fixed as it was assuming that previously seen statements in
new transactions would trigger this sampling behaviour when it should
not - this was being erronneously triggered by
BEGIN.Epic: none
Part of: #133307
Release note: None