Replace uses of fmt.Sprintf with string concatenation

[L3n41c]

What does this PR do?

Replace strings concatenation made with fmt.Sprintf by the standard Go string concatenation operator.

Motivation

fmt.Sprintf is a very inefficient way of concatenating strings.
I’m not only interested by the gain in CPU consumption, but also by the gain on stress on the GC by doing much less allocations.

package main

import (
        "flag"
        "fmt"
        "os"
        "strings"
        "testing"

        "github.com/stretchr/testify/assert"
)

var (
        key string
        value string
        expected string
)

func TestMain(m *testing.M) {
        flag.StringVar(&key, "key", "key", "key")
        flag.StringVar(&value, "value", "value", "value")
        flag.Parse()
        expected = key + ":" + value
        os.Exit(m.Run())
}

func BenchmarkSprintf(b *testing.B) {
        var tag string

        b.ReportAllocs()
        for b.Loop() {
                tag = fmt.Sprintf("%s:%s", key, value)
        }

        assert.Equal(b, expected, tag)
}

func BenchmarkConcat(b *testing.B) {
        var tag string

        b.ReportAllocs()
        for b.Loop() {
                tag = key + ":" + value
        }

        assert.Equal(b, expected, tag)
}

func BenchmarkStringBuffer(b *testing.B) {
        var tag strings.Builder

        b.ReportAllocs()
        for b.Loop() {
                tag.Reset()
                tag.Grow(len(key)+1+len(value))
                tag.WriteString(key)
                tag.WriteString(":")
                tag.WriteString(value)
        }

        assert.Equal(b, expected, tag.String())
}

$ go test -bench . -count=10 -args -key foo -value bar | ~/go/bin/benchstat -
goos: linux
goarch: amd64
pkg: bench
cpu: 12th Gen Intel(R) Core(TM) i9-12900H
                │      -      │
                │   sec/op    │
Sprintf-20        79.39n ± 3%
Concat-20         19.68n ± 1%
StringBuffer-20   22.48n ± 2%
geomean           32.75n

                │     -      │
                │    B/op    │
Sprintf-20        40.00 ± 0%
Concat-20         8.000 ± 0%
StringBuffer-20   8.000 ± 0%
geomean           13.68

                │     -      │
                │ allocs/op  │
Sprintf-20        3.000 ± 0%
Concat-20         1.000 ± 0%
StringBuffer-20   1.000 ± 0%
geomean           1.442

Describe how you validated your changes

No behavioral change.

Additional Notes

• Follow-up of Replace uses of fmt.Sprintf and fmt.Errorf with better alternatives #43413

[L3n41c]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Another round soon, please!

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[cit-pr-commenter]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Run ID: 4fd98739-4f68-4047-9471-5b92c0a9abbd

Baseline: 765a93f
Comparison: 9a42a15
Diff

Optimization Goals: ✅ No significant changes detected

Experiments ignored for regressions

Regressions in experiments with settings containing erratic: true are ignored.

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	docker_containers_cpu	% cpu utilization	-2.93	[-5.93, +0.06]	1	Logs

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	quality_gate_logs	% cpu utilization	+1.63	[+0.15, +3.10]	1	Logs bounds checks dashboard
➖	tcp_syslog_to_blackhole	ingress throughput	+1.56	[+1.47, +1.66]	1	Logs
➖	ddot_metrics	memory utilization	+1.35	[+1.14, +1.57]	1	Logs
➖	ddot_metrics_sum_delta	memory utilization	+0.66	[+0.46, +0.86]	1	Logs
➖	quality_gate_idle_all_features	memory utilization	+0.45	[+0.41, +0.48]	1	Logs bounds checks dashboard
➖	otlp_ingest_logs	memory utilization	+0.41	[+0.31, +0.52]	1	Logs
➖	uds_dogstatsd_20mb_12k_contexts_20_senders	memory utilization	+0.38	[+0.32, +0.43]	1	Logs
➖	quality_gate_idle	memory utilization	+0.10	[+0.06, +0.14]	1	Logs bounds checks dashboard
➖	ddot_metrics_sum_cumulativetodelta_exporter	memory utilization	+0.04	[-0.19, +0.28]	1	Logs
➖	file_to_blackhole_0ms_latency	egress throughput	+0.03	[-0.39, +0.45]	1	Logs
➖	otlp_ingest_metrics	memory utilization	+0.01	[-0.15, +0.17]	1	Logs
➖	uds_dogstatsd_to_api_v3	ingress throughput	+0.01	[-0.11, +0.13]	1	Logs
➖	file_to_blackhole_1000ms_latency	egress throughput	+0.01	[-0.42, +0.43]	1	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	+0.00	[-0.07, +0.08]	1	Logs
➖	uds_dogstatsd_to_api	ingress throughput	-0.02	[-0.14, +0.11]	1	Logs
➖	file_to_blackhole_100ms_latency	egress throughput	-0.03	[-0.07, +0.02]	1	Logs
➖	file_to_blackhole_500ms_latency	egress throughput	-0.03	[-0.41, +0.34]	1	Logs
➖	ddot_logs	memory utilization	-0.22	[-0.30, -0.15]	1	Logs
➖	docker_containers_memory	memory utilization	-0.40	[-0.47, -0.33]	1	Logs
➖	file_tree	memory utilization	-0.44	[-0.49, -0.39]	1	Logs
➖	ddot_metrics_sum_cumulative	memory utilization	-0.71	[-0.86, -0.56]	1	Logs
➖	quality_gate_metrics_logs	memory utilization	-1.22	[-1.43, -1.02]	1	Logs bounds checks dashboard
➖	docker_containers_cpu	% cpu utilization	-2.93	[-5.93, +0.06]	1	Logs

Bounds Checks: ✅ Passed

perf	experiment	bounds_check_name	replicates_passed	links
✅	docker_containers_cpu	simple_check_run	10/10
✅	docker_containers_memory	memory_usage	10/10
✅	docker_containers_memory	simple_check_run	10/10
✅	file_to_blackhole_0ms_latency	lost_bytes	10/10
✅	file_to_blackhole_0ms_latency	memory_usage	10/10
✅	file_to_blackhole_1000ms_latency	lost_bytes	10/10
✅	file_to_blackhole_1000ms_latency	memory_usage	10/10
✅	file_to_blackhole_100ms_latency	lost_bytes	10/10
✅	file_to_blackhole_100ms_latency	memory_usage	10/10
✅	file_to_blackhole_500ms_latency	lost_bytes	10/10
✅	file_to_blackhole_500ms_latency	memory_usage	10/10
✅	quality_gate_idle	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_idle	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_idle_all_features	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_idle_all_features	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_logs	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_logs	lost_bytes	10/10	bounds checks dashboard
✅	quality_gate_logs	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_metrics_logs	cpu_usage	10/10	bounds checks dashboard
✅	quality_gate_metrics_logs	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_metrics_logs	lost_bytes	10/10	bounds checks dashboard
✅	quality_gate_metrics_logs	memory_usage	10/10	bounds checks dashboard

Explanation

Confidence level: 90.00%
Effect size tolerance: |Δ mean %| ≥ 5.00%

Performance changes are noted in the perf column of each table:

• ✅ = significantly better comparison variant performance
• ❌ = significantly worse comparison variant performance
• ➖ = no significant change in performance

A regression test is an A/B test of target performance in a repeatable rig, where "performance" is measured as "comparison variant minus baseline variant" for an optimization goal (e.g., ingress throughput). Due to intrinsic variability in measuring that goal, we can only estimate its mean value for each experiment; we report uncertainty in that value as a 90.00% confidence interval denoted "Δ mean % CI".

For each experiment, we decide whether a change in performance is a "regression" -- a change worth investigating further -- if all of the following criteria are true:

1. Its estimated |Δ mean %| ≥ 5.00%, indicating the change is big enough to merit a closer look.

2. Its 90.00% confidence interval "Δ mean % CI" does not contain zero, indicating that if our statistical model is accurate, there is at least a 90.00% chance there is a difference in performance between baseline and comparison variants.

3. Its configuration does not mark it "erratic".

CI Pass/Fail Decision

✅ Passed. All Quality Gates passed.

• quality_gate_idle_all_features, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check lost_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check lost_bytes: 10/10 replicas passed. Gate passed.

[agent-platform-auto-pr]

Static quality checks

✅ Please find below the results from static quality gates
Comparison made with ancestor 9d97650

Successful checks

Info

	Quality gate	Delta	On disk size (MiB)	Delta	On wire size (MiB)
✅	agent_deb_amd64	$${-0}$$	$${705.65}$$ < $${706.32}$$	$${+0.02}$$	$${173.01}$$ < $${173.81}$$
✅	agent_deb_amd64_fips	$${0}$$	$${700.99}$$ < $${701.16}$$	$${+0.02}$$	$${172.03}$$ < $${172.71}$$
✅	agent_heroku_amd64	$${-0}$$	$${327.48}$$ < $${327.69}$$	$${+0}$$	$${87.37}$$ < $${88.19}$$
✅	agent_msi	$${-0.01}$$	$${980.09}$$ < $${982.08}$$	$${+0}$$	$${141.86}$$ < $${143.01}$$
✅	agent_rpm_amd64	$${-0}$$	$${705.64}$$ < $${706.31}$$	$${+0.01}$$	$${176.0}$$ < $${176.86}$$
✅	agent_rpm_amd64_fips	$${0}$$	$${700.98}$$ < $${701.15}$$	$${+0.04}$$	$${174.12}$$ < $${174.95}$$
✅	agent_rpm_arm64	$${-0}$$	$${691.32}$$ < $${691.67}$$	$${-0.04}$$	$${159.82}$$ < $${160.7}$$
✅	agent_rpm_arm64_fips	$${-0}$$	$${687.54}$$ < $${687.54}$$	$${-0.02}$$	$${159.27}$$ < $${160.1}$$
✅	agent_suse_amd64	$${-0}$$	$${705.64}$$ < $${706.31}$$	$${+0.01}$$	$${176.0}$$ < $${176.86}$$
✅	agent_suse_amd64_fips	$${0}$$	$${700.98}$$ < $${701.15}$$	$${+0.04}$$	$${174.12}$$ < $${174.95}$$
✅	agent_suse_arm64	$${-0}$$	$${691.32}$$ < $${691.67}$$	$${-0.04}$$	$${159.82}$$ < $${160.7}$$
✅	agent_suse_arm64_fips	$${-0}$$	$${687.54}$$ < $${687.54}$$	$${-0.02}$$	$${159.27}$$ < $${160.1}$$
✅	docker_agent_amd64	$${-0}$$	$${767.98}$$ < $${768.66}$$	$${-0}$$	$${260.75}$$ < $${261.52}$$
✅	docker_agent_arm64	$${-0}$$	$${777.93}$$ < $${778.35}$$	$${+0}$$	$${250.92}$$ < $${251.72}$$
✅	docker_agent_jmx_amd64	$${-0}$$	$${958.86}$$ < $${959.54}$$	$${-0}$$	$${329.37}$$ < $${330.15}$$
✅	docker_agent_jmx_arm64	$${-0}$$	$${957.53}$$ < $${957.95}$$	$${+0}$$	$${315.53}$$ < $${316.35}$$
✅	docker_cluster_agent_amd64	$${-0}$$	$${179.1}$$ < $${179.28}$$	$${-0}$$	$${63.25}$$ < $${63.96}$$
✅	docker_cluster_agent_arm64	$${0}$$	$${196.58}$$ < $${196.79}$$	$${-0}$$	$${59.96}$$ < $${60.69}$$
✅	docker_cws_instrumentation_amd64	$${0}$$	$${7.07}$$ < $${7.12}$$	$${-0}$$	$${2.95}$$ < $${3.29}$$
✅	docker_cws_instrumentation_arm64	$${-0}$$	$${6.69}$$ < $${6.92}$$	$${-0}$$	$${2.71}$$ < $${3.07}$$
✅	docker_dogstatsd_amd64	$${-0}$$	$${38.65}$$ < $${39.3}$$	$${-0}$$	$${14.93}$$ < $${15.76}$$
✅	docker_dogstatsd_arm64	$${0}$$	$${37.3}$$ < $${37.94}$$	$${-0}$$	$${14.37}$$ < $${14.83}$$
✅	dogstatsd_deb_amd64	$${0}$$	$${29.87}$$ < $${30.53}$$	$${+0}$$	$${7.88}$$ < $${8.75}$$
✅	dogstatsd_deb_arm64	$${0}$$	$${28.39}$$ < $${29.11}$$	$${-0}$$	$${6.81}$$ < $${7.71}$$
✅	dogstatsd_rpm_amd64	$${0}$$	$${29.87}$$ < $${30.53}$$	$${+0}$$	$${7.89}$$ < $${8.76}$$
✅	dogstatsd_suse_amd64	$${0}$$	$${29.87}$$ < $${30.53}$$	$${+0}$$	$${7.89}$$ < $${8.76}$$
✅	iot_agent_deb_amd64	$${0}$$	$${42.6}$$ < $${43.19}$$	$${-0}$$	$${11.12}$$ < $${11.98}$$
✅	iot_agent_deb_arm64	$${0}$$	$${40.34}$$ < $${40.92}$$	$${+0}$$	$${9.58}$$ < $${10.45}$$
✅	iot_agent_deb_armhf	$${0}$$	$${40.25}$$ < $${40.86}$$	$${-0}$$	$${9.69}$$ < $${10.56}$$
✅	iot_agent_rpm_amd64	$${0}$$	$${42.6}$$ < $${43.19}$$	$${-0.01}$$	$${11.14}$$ < $${12.0}$$
✅	iot_agent_suse_amd64	$${0}$$	$${42.6}$$ < $${43.19}$$	$${-0.01}$$	$${11.14}$$ < $${12.0}$$

[bitomaxsp]

I reviewed all changes except samber addition

[L3n41c]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Keep them coming!

ℹ️ About Codex in GitHub

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Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[L3n41c]

/merge

[dd-devflow-routing-codex]

View all feedbacks in Devflow UI.

2025-12-10 14:51:58 UTC ℹ️ Start processing command /merge

---

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This pull request is not mergeable according to GitHub. Common reasons include pending required checks, missing approvals, or merge conflicts — but it could also be blocked by other repository rules or settings.
It will be added to the queue as soon as checks pass and/or get approvals.
Note: if you pushed new commits since the last approval, you may need additional approval.
You can remove it from the waiting list with /remove command.

---

2025-12-10 16:17:29 UTC ℹ️ MergeQueue: merge request added to the queue

The expected merge time in main is approximately 42m (p90).

---

2025-12-10 16:18:07 UTC ❌ MergeQueue: This merge request has conflicts

This merge request conflicts with another merge request ahead in the queue.

The merge requests in front of this one are:

• #43909 with merge sha 42425f1
• #44053 with merge sha b2d2a5a

[dd-devflow-routing-codex]

View all feedbacks in Devflow UI.

2025-12-10 16:37:56 UTC ℹ️ Start processing command /merge

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2025-12-10 16:38:05 UTC ℹ️ MergeQueue: waiting for PR to be ready

This pull request is not mergeable according to GitHub. Common reasons include pending required checks, missing approvals, or merge conflicts — but it could also be blocked by other repository rules or settings.
It will be added to the queue as soon as checks pass and/or get approvals.
Note: if you pushed new commits since the last approval, you may need additional approval.
You can remove it from the waiting list with /remove command.

---

2025-12-10 19:04:21 UTC ℹ️ MergeQueue: merge request added to the queue

The expected merge time in main is approximately 41m (p90).

---

2025-12-10 19:34:13 UTC ℹ️ MergeQueue: This merge request was merged