fix: the translator no longer panics on a label name holding its key-list separator bytes

[szibis]

Summary

FuzzTranslateWithStreamFields found a panic in the query translator (CI fuzz-smoke):

{app="x"} | json | \x01a_b="v"
panic: runtime error: index out of range [0] with length 0
  translateParsedKeyFilter (parsed_key_variants.go:130)

The translator encodes the candidate keys of a sanitized label as one string: keys are joined by \x00, and a name_extracted collision candidate is marked with a leading \x01. A label name that itself held those bytes was decoded as a key list: a leading \x01 recursed past the end of the list, and an inner \x00 split one name into two keys.

• withParsedKeyVariants leaves a name holding either byte as a plain name.
• translateSingleLabelFilter splits the translation into keys only when the label name itself holds no separator.

Client impact

None. The request path validates the query with the Loki grammar first and answers Loki's parse error (400) for these names, so only direct translator callers (and the fuzz target) could reach the panic.

Tests

• TestParsedKeyFilterNameWithSeparatorBytes: panics on main, passes here.
• FuzzTranslateWithStreamFields for 60 s locally: pass.
• go test -short ./internal/translator ./internal/proxy, golangci-lint, the changelog and conformance gates: pass.

No change to translated queries for valid label names, so no A/B or e2e run.

[github-actions]

⚪ Performance A/B: no change beyond noise

105 shape×range — 105 ⚪ same · results vs Loki: 88 same, 0 new difference(s), 17 pre-existing

Every shape is within noise of the base build (±30% and 100 ms).

105 unchanged shape×range (within noise)

	shape	range	base p50	PR p50	change	Loki p50	PR ÷ Loki	result vs Loki
⚪	bytes_over_time by app	1h	68 ms	69 ms	⚪ +1%	89 ms	0.78×	✅ same
⚪	drilldown service landing	1h	38 ms	33 ms	⚪ -13%	26 ms	1.27×	✅ same
⚪	instant json filtered	instant	364 ms	373 ms	⚪ +2%	76 ms	4.91×	✅ same
⚪	instant json volume	instant	404 ms	409 ms	⚪ +1%	98 ms	4.17×	✅ same
⚪	instant ungrouped rate	instant	9 ms	8 ms	⚪ -11%	74 ms	0.11×	✅ same
⚪	json rate by level (no filter, no drop)	1h	400	400	⚪ +0%	400	—	✅ same
⚪	json volume no filters	1h	202 ms	201 ms	⚪ -0%	3 ms	67×	✅ same
⚪	logfmt count by level, filter, drop	1h	429 ms	439 ms	⚪ +2%	59 ms	7.44×	✅ same
⚪	logfmt volume	1h	312 ms	313 ms	⚪ +0%	62 ms	5.05×	✅ same
⚪	logs plain	1h	72 ms	68 ms	⚪ -6%	42 ms	1.62×	✅ same
⚪	logs | json	1h	101 ms	98 ms	⚪ -3%	64 ms	1.53×	✅ same
⚪	logs | logfmt	1h	150 ms	156 ms	⚪ +4%	51 ms	3.06×	✅ same
⚪	stream-label count by app	1h	32 ms	25 ms	⚪ -22%	39 ms	0.64×	✅ same
⚪	topk rate by app	1h	45 ms	45 ms	⚪ +0%	87 ms	0.52×	➖ differs (as base)
⚪	ungrouped rate	1h	19 ms	12 ms	⚪ -37%	81 ms	0.15×	✅ same
⚪	DB3 json field breakdown user_id	1h	51 ms	50 ms	⚪ -2%	25 ms	2.00×	✅ same
⚪	DB4 json field breakdown batch_id	1h	99 ms	92 ms	⚪ -7%	54 ms	1.70×	✅ same
⚪	X1 json filter level_extracted, by level	1h	413 ms	432 ms	⚪ +5%	45 ms	9.60×	✅ same
⚪	X2 json group by level_extracted	1h	341 ms	342 ms	⚪ +0%	48 ms	7.12×	✅ same
⚪	X3 json rate, level_extracted equality	1h	322 ms	313 ms	⚪ -3%	37 ms	8.46×	✅ same
⚪	X4 json bytes, level_extracted regexp	1h	434 ms	448 ms	⚪ +3%	94 ms	4.77×	✅ same
⚪	X5 logfmt filter level_extracted, by level	1h	737 ms	696 ms	⚪ -6%	56 ms	12×	✅ same
⚪	E1 logs, json parser over stream labels	1h	118 ms	114 ms	⚪ -3%	63 ms	1.81×	✅ same
⚪	E2 logs, logfmt parser over stream labels	1h	84 ms	78 ms	⚪ -7%	53 ms	1.47×	✅ same
⚪	E3 logs, json, existence filter on level_extracted	1h	151 ms	145 ms	⚪ -4%	81 ms	1.79×	✅ same
⚪	E4 logs, logfmt, existence filter on level_extracted	1h	99 ms	89 ms	⚪ -10%	57 ms	1.56×	✅ same
⚪	E5 logs, json, drop level_extracted	1h	116 ms	111 ms	⚪ -4%	62 ms	1.79×	✅ same
⚪	E6 logfmt count by level_extracted	1h	46 ms	46 ms	⚪ +0%	8 ms	5.75×	✅ same
⚪	E7 json count by level_extracted	1h	163 ms	159 ms	⚪ -2%	16 ms	9.94×	✅ same
⚪	E8 instant logfmt by level_extracted	instant	7 ms	7 ms	⚪ +0%	11 ms	0.64×	✅ same
⚪	A explore volume, 2 filters, drop	1h	174 ms	167 ms	⚪ -4%	110 ms	1.52×	✅ same
⚪	B grouped sum, filter, no drop	1h	106 ms	101 ms	⚪ -5%	37 ms	2.73×	✅ same
⚪	C ungrouped sum, filter, no drop	1h	102 ms	104 ms	⚪ +2%	35 ms	2.97×	✅ same
⚪	D volume, no filters	1h	227 ms	230 ms	⚪ +1%	47 ms	4.89×	✅ same
⚪	E field breakdown pipeline (explore)	1h	101 ms	103 ms	⚪ +2%	37 ms	2.78×	✅ same
⚪	F field breakdown service_version (explore)	1h	147 ms	166 ms	⚪ +13%	43 ms	3.86×	✅ same
⚪	G field breakdown pipeline (drilldown)	1h	59 ms	59 ms	⚪ +0%	23 ms	2.57×	✅ same
⚪	H field breakdown service_version (drilldown)	1h	88 ms	93 ms	⚪ +6%	25 ms	3.72×	✅ same
⚪	I grafana volume of B	1h	98 ms	100 ms	⚪ +2%	36 ms	2.78×	✅ same
⚪	O2 explore log volume (Grafana form), underscore structured-metadata filter	1h	70 ms	70 ms	⚪ +0%	36 ms	1.94×	✅ same
⚪	DL1 drilldown field breakdown json-expr, level filter	1h	489 ms	485 ms	⚪ -1%	23 ms	21×	✅ same
⚪	DL2 drilldown field breakdown, level + stream-label filter before json	1h	49 ms	52 ms	⚪ +6%	8 ms	6.50×	✅ same
⚪	DL3 drilldown logfmt field breakdown, level filter	1h	624 ms	634 ms	⚪ +2%	92 ms	6.89×	➖ differs (as base)
⚪	DL4 instant count, level filter, json+logfmt, 1h	instant	522 ms	514 ms	⚪ -2%	1.35 s	0.38×	✅ sum ±0.29%
⚪	DL6 explore volume, level filter before json	1h	500 ms	499 ms	⚪ -0%	41 ms	12×	✅ sum ±0.30%
⚪	OR1 logs, or alternatives	1h	86 ms	77 ms	⚪ -10%	68 ms	1.13×	✅ same
⚪	OR2 logs, negated or alternatives	1h	73 ms	68 ms	⚪ -7%	50 ms	1.36×	✅ same
⚪	OR3 logs, regexp or alternatives	1h	67 ms	63 ms	⚪ -6%	71 ms	0.89×	✅ same
⚪	OR4 count by level, or alternatives with parser	1h	83 ms	84 ms	⚪ +1%	32 ms	2.62×	✅ same
⚪	OR5 rate, negated regexp or alternatives	1h	59 ms	59 ms	⚪ +0%	90 ms	0.66×	✅ same
⚪	OR6 instant, or alternatives	instant	8 ms	9 ms	⚪ +12%	66 ms	0.14×	✅ same
⚪	P1 api-gateway empty pattern	1h	24 ms	24 ms	⚪ +0%	7 ms	3.43×	✅ same
⚪	P2 api-gateway not empty pattern, line filter	1h	76 ms	78 ms	⚪ +3%	21 ms	3.71×	✅ same
⚪	P3 nginx count_over_time, pattern with spaces	1h	14 ms	13 ms	⚪ -7%	7 ms	1.86×	✅ same
⚪	P4 nginx count_over_time, GET request pattern	1h	15 ms	15 ms	⚪ +0%	6 ms	2.50×	✅ same
⚪	A1 nginx include GET, log query	1h	18 ms	19 ms	⚪ +6%	11 ms	1.73×	✅ same
⚪	A2 nginx exclude GET, log query	1h	21 ms	21 ms	⚪ +0%	15 ms	1.40×	✅ same
⚪	A3 nginx include GET, count_over_time	1h	1 ms	1 ms	⚪ +0%	2 ms	0.50×	✅ same
⚪	A4 nginx exclude GET, count_over_time	1h	20 ms	21 ms	⚪ +5%	7 ms	3.00×	✅ same
⚪	A5 drilldown exclude, volume by detected_level	1h	25 ms	24 ms	⚪ -4%	6 ms	4.00×	✅ same
⚪	A6 nginx include ends on a literal, log query	1h	14 ms	15 ms	⚪ +7%	5 ms	3.00×	✅ same
⚪	A7 nginx exclude ends on a literal, log query	1h	17 ms	17 ms	⚪ +0%	16 ms	1.06×	✅ same
⚪	A8 nginx include two literals, count_over_time	1h	26 ms	26 ms	⚪ +0%	6 ms	4.33×	✅ same
⚪	A9 nginx include two literals, ends on a literal, count_over_time	1h	23 ms	23 ms	⚪ +0%	6 ms	3.83×	✅ same
⚪	P1 logs, json, level equals	1h	135 ms	128 ms	⚪ -5%	80 ms	1.60×	✅ same
⚪	P2 logs, logfmt, level not equal	1h	31 ms	32 ms	⚪ +3%	5 ms	6.40×	✅ same
⚪	P3 logs, json, level existence	1h	132 ms	130 ms	⚪ -2%	68 ms	1.91×	✅ same
⚪	P4 logfmt count by level	1h	33 ms	33 ms	⚪ +0%	7 ms	4.71×	✅ same
⚪	P5 json count by level	1h	87 ms	90 ms	⚪ +3%	16 ms	5.62×	✅ same
⚪	P6 json count, level filter	1h	20 ms	17 ms	⚪ -15%	14 ms	1.21×	✅ same
⚪	P7 json rate by level, level regexp	1h	18 ms	19 ms	⚪ +6%	15 ms	1.27×	✅ same
⚪	P8 json count by a name that is no stream label	1h	93 ms	89 ms	⚪ -4%	14 ms	6.36×	✅ same
⚪	P9 instant logfmt by level	instant	6 ms	6 ms	⚪ +0%	10 ms	0.60×	✅ same
⚪	E1 json duration_ms sum by service	1h	91 ms	92 ms	⚪ +1%	16 ms	5.75×	➖ differs (as base)
⚪	E2 json duration_ms p95 by service	1h	326 ms	336 ms	⚪ +3%	16 ms	21×	✅ same
⚪	E3 logfmt latency_ms rate, production	1h	488 ms	500 ms	⚪ +2%	128 ms	3.91×	➖ differs (as base)
⚪	E4 logfmt size_bytes max by service	1h	48 ms	46 ms	⚪ -4%	16 ms	2.88×	➖ differs (as base)
⚪	E5 json duration_ms sum, instant	instant	30 ms	29 ms	⚪ -3%	28 ms	1.04×	✅ same
⚪	E6 logfmt ttl unit string (Loki 400)	1h	400	400	⚪ +3%	400	—	✅ same
⚪	E7 json hexadecimal trace_id (Loki 400)	1h	400	400	⚪ +0%	400	—	✅ same
⚪	E8 json duration_ms sum by service, namespace prod	1h	193 ms	194 ms	⚪ +1%	82 ms	2.37×	➖ differs (as base)
⚪	E9 logfmt latency_ms sum by service, namespace prod	1h	302 ms	299 ms	⚪ -1%	90 ms	3.32×	➖ differs (as base)
⚪	U1 logfmt amount rate	1h	39 ms	37 ms	⚪ -5%	14 ms	2.64×	✅ same
⚪	U2 json duration_ms rate	1h	91 ms	92 ms	⚪ +1%	24 ms	3.83×	✅ same
⚪	U3 json duration_ms rate, error filter	1h	91 ms	90 ms	⚪ -1%	29 ms	3.10×	✅ same
⚪	U4 logfmt latency_ms rate, production	1h	351 ms	353 ms	⚪ +1%	126 ms	2.80×	➖ differs (as base)
⚪	U5 logfmt amount rate, instant	instant	8 ms	7 ms	⚪ -12%	12 ms	0.58×	✅ same
⚪	U6 json duration_ms rate, instant	instant	13 ms	13 ms	⚪ +0%	20 ms	0.65×	✅ same
⚪	U7 json duration_ms sum_over_time, instant	instant	16 ms	16 ms	⚪ +0%	21 ms	0.76×	✅ same
⚪	U8 logfmt amount rate by service (grouped)	1h	44 ms	43 ms	⚪ -2%	13 ms	3.31×	✅ same
⚪	U9 logfmt amount rate_counter (folded per series)	1h	230 ms	224 ms	⚪ -3%	33 ms	6.79×	➖ differs (as base)
⚪	U1 json duration_ms sum by service	1h	93 ms	86 ms	⚪ -8%	16 ms	5.37×	➖ differs (as base)
⚪	U10 instant sum_over_time unwrap	instant	29 ms	31 ms	⚪ +7%	29 ms	1.07×	✅ same
⚪	U11 instant max_over_time missing label	instant	6 ms	5 ms	⚪ -17%	16 ms	0.31×	✅ same
⚪	U12 json duration_ms over every service	1h	248 ms	255 ms	⚪ +3%	44 ms	5.80×	➖ differs (as base)
⚪	U13 logfmt latency_ms over every service	1h	506 ms	503 ms	⚪ -1%	58 ms	8.67×	➖ differs (as base)
⚪	U14 duration() of a unit string	1h	47 ms	44 ms	⚪ -6%	8 ms	5.50×	➖ differs (as base)
⚪	U2 json duration_ms max by service	1h	98 ms	103 ms	⚪ +5%	43 ms	2.40×	➖ differs (as base)
⚪	U3 json duration_ms sliding sum	1h	92 ms	86 ms	⚪ -7%	34 ms	2.53×	➖ differs (as base)
⚪	U4 logfmt size_bytes sum by service	1h	41 ms	39 ms	⚪ -5%	7 ms	5.57×	➖ differs (as base)
⚪	U5 logfmt ttl unit string (no sample)	1h	41 ms	41 ms	⚪ +0%	7 ms	5.86×	✅ same
⚪	U6 missing label, no parser	1h	23 ms	23 ms	⚪ +0%	10 ms	2.30×	✅ same
⚪	U7 missing label, ungrouped sum	1h	22 ms	22 ms	⚪ +0%	9 ms	2.44×	✅ same
⚪	U8 rate of an unwrapped label	1h	93 ms	89 ms	⚪ -4%	16 ms	5.56×	✅ same
⚪	U9 bytes() conversion	1h	52 ms	54 ms	⚪ +4%	12 ms	4.50×	➖ differs (as base)

Cold (first-run) timings — what a user opening a panel sees

shape	range	base cold	PR cold	Loki cold	PR ÷ Loki cold
bytes_over_time by app	1h	73 ms	73 ms	729 ms	0.10×
drilldown service landing	1h	39 ms	38 ms	522 ms	0.07×
instant json filtered	instant	390 ms	386 ms	77 ms	5.01×
instant json volume	instant	441 ms	428 ms	102 ms	4.20×
instant ungrouped rate	instant	8 ms	8 ms	76 ms	0.11×
json rate by level (no filter, no drop)	1h	400	400	400	—
json volume no filters	1h	204 ms	211 ms	3 ms	70.33×
logfmt count by level, filter, drop	1h	437 ms	436 ms	976 ms	0.45×
logfmt volume	1h	250 ms	239 ms	1.08 s	0.22×
logs plain	1h	96 ms	80 ms	45 ms	1.78×
logs | json	1h	124 ms	105 ms	65 ms	1.62×
logs | logfmt	1h	171 ms	166 ms	56 ms	2.96×
stream-label count by app	1h	26 ms	29 ms	517 ms	0.06×
topk rate by app	1h	64 ms	69 ms	566 ms	0.12×
ungrouped rate	1h	12 ms	12 ms	679 ms	0.02×
DB3 json field breakdown user_id	1h	69 ms	53 ms	643 ms	0.08×
DB4 json field breakdown batch_id	1h	99 ms	126 ms	497 ms	0.25×
X1 json filter level_extracted, by level	1h	3.99 s	3.97 s	779 ms	5.10×
X2 json group by level_extracted	1h	383 ms	345 ms	685 ms	0.50×
X3 json rate, level_extracted equality	1h	310 ms	312 ms	513 ms	0.61×
X4 json bytes, level_extracted regexp	1h	448 ms	443 ms	769 ms	0.58×
X5 logfmt filter level_extracted, by level	1h	704 ms	703 ms	914 ms	0.77×
E1 logs, json parser over stream labels	1h	147 ms	121 ms	66 ms	1.83×
E2 logs, logfmt parser over stream labels	1h	77 ms	68 ms	56 ms	1.21×
E3 logs, json, existence filter on level_extracted	1h	154 ms	144 ms	215 ms	0.67×
E4 logs, logfmt, existence filter on level_extracted	1h	102 ms	95 ms	69 ms	1.38×
E5 logs, json, drop level_extracted	1h	124 ms	115 ms	61 ms	1.89×
E6 logfmt count by level_extracted	1h	46 ms	46 ms	37 ms	1.24×
E7 json count by level_extracted	1h	1.58 s	1.56 s	180 ms	8.66×
E8 instant logfmt by level_extracted	instant	8 ms	9 ms	10 ms	0.90×
A explore volume, 2 filters, drop	1h	2.60 s	1.83 s	1.15 s	1.60×
B grouped sum, filter, no drop	1h	126 ms	129 ms	485 ms	0.27×
C ungrouped sum, filter, no drop	1h	124 ms	123 ms	487 ms	0.25×
D volume, no filters	1h	211 ms	213 ms	855 ms	0.25×
E field breakdown pipeline (explore)	1h	108 ms	106 ms	476 ms	0.22×
F field breakdown service_version (explore)	1h	1.49 s	1.47 s	528 ms	2.77×
G field breakdown pipeline (drilldown)	1h	47 ms	45 ms	674 ms	0.07×
H field breakdown service_version (drilldown)	1h	144 ms	142 ms	520 ms	0.27×
I grafana volume of B	1h	120 ms	127 ms	470 ms	0.27×
O2 explore log volume (Grafana form), underscore structured-metadata filter	1h	176 ms	153 ms	494 ms	0.31×
DL1 drilldown field breakdown json-expr, level filter	1h	499 ms	482 ms	412 ms	1.17×
DL2 drilldown field breakdown, level + stream-label filter before json	1h	86 ms	85 ms	28 ms	3.04×
DL3 drilldown logfmt field breakdown, level filter	1h	645 ms	642 ms	897 ms	0.72×
DL4 instant count, level filter, json+logfmt, 1h	instant	521 ms	514 ms	1.38 s	0.37×
DL6 explore volume, level filter before json	1h	1.02 s	1.00 s	699 ms	1.43×
OR1 logs, or alternatives	1h	101 ms	76 ms	66 ms	1.15×
OR2 logs, negated or alternatives	1h	77 ms	83 ms	52 ms	1.60×
OR3 logs, regexp or alternatives	1h	65 ms	62 ms	70 ms	0.89×
OR4 count by level, or alternatives with parser	1h	127 ms	126 ms	558 ms	0.23×
OR5 rate, negated regexp or alternatives	1h	57 ms	57 ms	603 ms	0.09×
OR6 instant, or alternatives	instant	7 ms	8 ms	68 ms	0.12×
P1 api-gateway empty pattern	1h	46 ms	24 ms	60 ms	0.40×
P2 api-gateway not empty pattern, line filter	1h	84 ms	79 ms	21 ms	3.76×
P3 nginx count_over_time, pattern with spaces	1h	13 ms	14 ms	21 ms	0.67×
P4 nginx count_over_time, GET request pattern	1h	22 ms	18 ms	26 ms	0.69×
A1 nginx include GET, log query	1h	35 ms	19 ms	12 ms	1.58×
A2 nginx exclude GET, log query	1h	24 ms	22 ms	12 ms	1.83×
A3 nginx include GET, count_over_time	1h	1 ms	1 ms	2 ms	0.50×
A4 nginx exclude GET, count_over_time	1h	19 ms	22 ms	28 ms	0.79×
A5 drilldown exclude, volume by detected_level	1h	25 ms	24 ms	25 ms	0.96×
A6 nginx include ends on a literal, log query	1h	14 ms	14 ms	24 ms	0.58×
A7 nginx exclude ends on a literal, log query	1h	19 ms	17 ms	16 ms	1.06×
A8 nginx include two literals, count_over_time	1h	25 ms	25 ms	29 ms	0.86×
A9 nginx include two literals, ends on a literal, count_over_time	1h	23 ms	23 ms	25 ms	0.92×
P1 logs, json, level equals	1h	200 ms	151 ms	135 ms	1.12×
P2 logs, logfmt, level not equal	1h	40 ms	32 ms	34 ms	0.94×
P3 logs, json, level existence	1h	126 ms	125 ms	75 ms	1.67×
P4 logfmt count by level	1h	33 ms	34 ms	44 ms	0.77×
P5 json count by level	1h	104 ms	96 ms	159 ms	0.60×
P6 json count, level filter	1h	22 ms	29 ms	163 ms	0.18×
P7 json rate by level, level regexp	1h	18 ms	22 ms	141 ms	0.16×
P8 json count by a name that is no stream label	1h	107 ms	104 ms	123 ms	0.85×
P9 instant logfmt by level	instant	6 ms	9 ms	10 ms	0.90×
E1 json duration_ms sum by service	1h	107 ms	90 ms	159 ms	0.57×
E2 json duration_ms p95 by service	1h	344 ms	342 ms	183 ms	1.87×
E3 logfmt latency_ms rate, production	1h	483 ms	485 ms	893 ms	0.54×
E4 logfmt size_bytes max by service	1h	45 ms	46 ms	193 ms	0.24×
E5 json duration_ms sum, instant	instant	33 ms	31 ms	32 ms	0.97×
E6 logfmt ttl unit string (Loki 400)	1h	400	400	400	—
E7 json hexadecimal trace_id (Loki 400)	1h	400	400	400	—
E8 json duration_ms sum by service, namespace prod	1h	196 ms	204 ms	647 ms	0.32×
E9 logfmt latency_ms sum by service, namespace prod	1h	291 ms	308 ms	572 ms	0.54×
U1 logfmt amount rate	1h	58 ms	39 ms	47 ms	0.83×
U2 json duration_ms rate	1h	92 ms	93 ms	128 ms	0.73×
U3 json duration_ms rate, error filter	1h	94 ms	91 ms	234 ms	0.39×
U4 logfmt latency_ms rate, production	1h	350 ms	352 ms	829 ms	0.42×
U5 logfmt amount rate, instant	instant	8 ms	8 ms	11 ms	0.73×
U6 json duration_ms rate, instant	instant	13 ms	15 ms	23 ms	0.65×
U7 json duration_ms sum_over_time, instant	instant	17 ms	18 ms	23 ms	0.78×
U8 logfmt amount rate by service (grouped)	1h	43 ms	42 ms	57 ms	0.74×
U9 logfmt amount rate_counter (folded per series)	1h	233 ms	227 ms	470 ms	0.48×
U1 json duration_ms sum by service	1h	107 ms	88 ms	161 ms	0.55×
U10 instant sum_over_time unwrap	instant	35 ms	29 ms	29 ms	1.00×
U11 instant max_over_time missing label	instant	5 ms	6 ms	16 ms	0.38×
U12 json duration_ms over every service	1h	246 ms	250 ms	599 ms	0.42×
U13 logfmt latency_ms over every service	1h	504 ms	507 ms	1.10 s	0.46×
U14 duration() of a unit string	1h	47 ms	44 ms	38 ms	1.16×
U2 json duration_ms max by service	1h	101 ms	101 ms	862 ms	0.12×
U3 json duration_ms sliding sum	1h	94 ms	87 ms	174 ms	0.50×
U4 logfmt size_bytes sum by service	1h	41 ms	40 ms	42 ms	0.95×
U5 logfmt ttl unit string (no sample)	1h	41 ms	40 ms	40 ms	1.00×
U6 missing label, no parser	1h	23 ms	24 ms	76 ms	0.32×
U7 missing label, ungrouped sum	1h	27 ms	21 ms	65 ms	0.32×
U8 rate of an unwrapped label	1h	95 ms	98 ms	161 ms	0.61×
U9 bytes() conversion	1h	54 ms	52 ms	45 ms	1.16×

Why these shapes

• internal/translator/translator.go → 103: control/bytes_over_time by app, control/instant json filtered, control/instant json volume, control/instant ungrouped rate, control/json rate by level (no filter, no drop), control/json volume no filters, control/logfmt count by level, filter, drop, control/logfmt volume …
• internal/translator/parsed_key_variants.go → 59: control/instant json filtered, control/instant json volume, control/json rate by level (no filter, no drop), control/json volume no filters, extracted-pushdown/X1 json filter level_extracted, by level, extracted-pushdown/X2 json group by level_extracted, extracted-pushdown/X3 json rate, level_extracted equality, extracted-pushdown/X4 json bytes, level_extracted regexp …
• control smoke → 8: control/drilldown service landing, control/instant ungrouped rate, control/json rate by level (no filter, no drop), control/json volume no filters, control/logs plain, control/logs | json, control/stream-label count by app, control/topk rate by app

_{base 1dcb79e0fe → PR 17ae095659 · 4 runs (first is cold), warm p50 · ranges 1h · noise ±30% and 100 ms · VictoriaLogs restarts 0→0 · 10.4 min. Same runner, one fresh stack, targets interleaved per request. How to read and reproduce: bench/ab/README.md.}

[github-actions]

PR Quality Report

Compared against base branch main.

Coverage and tests

Signal	Base	PR	Delta
Test count	9738	9739	1
Coverage	87.9%	87.9%	0.0% (stable)

Compatibility

Track	Base	PR	Delta
Loki API	100.0%	11/11 (100.0%)	0.0% (stable)
Logs Drilldown	100.0%	17/17 (100.0%)	0.0% (stable)
VictoriaLogs	100.0%	11/11 (100.0%)	0.0% (stable)

Performance smoke

Lower CPU cost (ns/op) is better. Lower benchmark memory cost (B/op, allocs/op) is better. Higher throughput is better. Lower load-test memory growth is better. Benchmark rows are medians from repeated samples.

Signal	Base	PR	Delta
QueryRange cache-hit CPU cost	3387.0 ns/op	3515.0 ns/op	+3.8% (stable)
QueryRange cache-hit memory	1240.0 B/op	1240.0 B/op	0.0% (stable)
QueryRange cache-hit allocations	27.0 allocs/op	27.0 allocs/op	0.0% (stable)
QueryRange cache-bypass CPU cost	4352.0 ns/op	4234.0 ns/op	-2.7% (stable)
QueryRange cache-bypass memory	1304.0 B/op	1303.0 B/op	-0.1% (stable)
QueryRange cache-bypass allocations	27.0 allocs/op	27.0 allocs/op	0.0% (stable)
Labels cache-hit CPU cost	892.7 ns/op	911.9 ns/op	+2.2% (stable)
Labels cache-hit memory	48.0 B/op	48.0 B/op	0.0% (stable)
Labels cache-hit allocations	3.0 allocs/op	3.0 allocs/op	0.0% (stable)
Labels cache-bypass CPU cost	1571.0 ns/op	1512.0 ns/op	-3.8% (stable)
Labels cache-bypass memory	399.0 B/op	399.0 B/op	0.0% (stable)
Labels cache-bypass allocations	14.0 allocs/op	14.0 allocs/op	0.0% (stable)

State

• Coverage, compatibility, and sampled performance are reported here from the same PR workflow.
• This is a delta report, not a release gate by itself. Required checks still decide merge safety.
• Performance is a smoke comparison, not a full benchmark lab run.
• Delta states use the same noise guards as the quality gate (percent + absolute + low-baseline checks), so report labels match merge-gate behavior.

[github-actions]

✅ Visual smoke: passed

Base 1dcb79e0fe vs PR c94b583260, Grafana through the proxy builds and Loki on one fresh stack; run.
Core set: 5 capture(s) at 1h. Detailed set: 26 entries (explore-metric-plain, explore-A, explore-B, explore-C, explore-E, explore-F, explore-logs-json, explore-logfmt-metric, ...). 32 capture(s), 15m/1h/6h, 24h and 7d stay out of PR runs.
Trimmed to the 1h range for the capture budget: explore-A, explore-B, explore-C, explore-E, explore-F, explore-logs-json, explore-logfmt-metric, explore-logs-extracted, explore-extracted-metric, explore-extracted-filter-metric, explore-extracted-group-metric, explore-logs-plain-level, explore-plain-level-metric, explore-logs-line-filter-or, explore-metric-line-filter-or, explore-unwrap-sum, explore-unwrap-unit-string, explore-unwrap-missing-label, explore-unwrap-conversion-error, explore-unwrap-rate-sum, explore-empty-pattern-filter, explore-pattern-filter-anchored, dd-field-service_version, dd-field-pipeline.

page	range	set	base = PR (data)	vs Loki (PR)	pixel diff	result
dd-fields	1h	core	✅ identical	identical (4 explained, 1 history-dependent)	0.11%	✅
dd-landing	1h	core	✅ identical	identical (3 explained)	0.13%	✅
dd-service-logs	1h	core	✅ identical	identical (3 explained, 1 history-dependent)	0.11%	✅
explore-logs-plain	1h	core	✅ identical	identical (1 explained)	0.07%	✅
explore-metric-plain	1h	core	✅ identical	identical (1 explained)	0.04%	✅
dd-field-pipeline	1h	detailed	✅ identical	identical (3 explained, 1 history-dependent)	0.11%	✅
dd-field-service_version	1h	detailed	✅ identical	identical (3 explained, 1 history-dependent)	0.11%	✅
explore-A	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-B	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-C	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-E	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-F	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-empty-pattern-filter	1h	detailed	✅ identical	identical (1 explained)	0.07%	✅
explore-extracted-filter-metric	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-extracted-group-metric	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-extracted-metric	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-logfmt-metric	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-logs-extracted	1h	detailed	✅ identical	identical (1 explained)	0.07%	✅
explore-logs-json	1h	detailed	✅ identical	identical (1 explained)	0.07%	✅
explore-logs-line-filter-or	1h	detailed	✅ identical	identical (1 explained)	0.07%	✅
explore-logs-plain-level	1h	detailed	✅ identical	identical (2 explained)	0.07%	✅
explore-metric-line-filter-or	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-metric-plain	15m	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-metric-plain	6h	detailed	✅ identical	n/a (beyond the Loki window)	0.04%	✅
explore-pattern-filter-anchored	1h	detailed	✅ identical	identical (1 explained)	0.07%	✅
explore-plain-level-metric	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-unwrap-conversion-error	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-unwrap-missing-label	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-unwrap-rate-sum	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
explore-unwrap-sum	1h	detailed	✅ identical	1 difference(s), 1 on base too; 1 explained	0.04%	✅
explore-unwrap-unit-string	1h	detailed	✅ identical	identical (1 explained)	0.04%	✅
tail-json-filter	live	detailed	✅ identical	entries in the window: PR 1904, Loki 687, in both 687	7.15%	✅

Gate: a base-vs-PR data difference passes when the PR is closer to Loki, and fails when the PR diverges from Loki or Loki cannot decide it (at a range Loki does not hold, a difference passes when the same page proved it closer to Loki at a shorter range; otherwise label the pull request visual-change-expected to accept an intended change). Also failing: a panel empty on the PR but not on the base, an error banner, panel error, error answer or new "No data" panel on the PR, a PR side that never settled, a difference that did not reproduce on the recapture. Pixel differences only warn.

Core set montages (5): base | PR | Loki

dd-fields-1h

dd-landing-1h

dd-service-logs-1h

explore-logs-plain-1h

explore-metric-plain-1h

All montages of this run: pr-visuals/pr-761.