> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vortexiq.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Error Rate, New Relic

> Error Rate for New Relic stores. Tracked live in Vortex IQ Nerve Centre. How to read it, why it matters, and how to act on it.

**Metrics type:** [Key Metrics](/nerve-centre/overview#metrics-types-explained)  •  **Category:** [Monitoring](/nerve-centre/connectors#connectors-by-type)

## At a glance

> Percentage of `Transaction` events that ended in an error in the rolling window. The fastest leading-edge signal of a deploy gone wrong, an upstream dependency crashing, or a database hitting connection-pool exhaustion. The card a duty engineer should pin to a second monitor.

|                               |                                                                                                                                                                                                                                                                                                                                     |
| ----------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **What it counts**            | `errorCount / count(*) FROM Transaction x 100`, expressed as a percentage. An error is any `Transaction` event with `error IS true` (set by the APM agent on uncaught exceptions, 5xx responses, and explicit `noticeError()` calls).                                                                                               |
| **NerdGraph endpoint**        | NRQL via [NerdGraph](https://api.newrelic.com/graphql): `SELECT percentage(count(*), WHERE error IS true) FROM Transaction WHERE appName IN (...) SINCE 5 MINUTES AGO`.                                                                                                                                                             |
| **Metric basis**              | Event-rate (not request-rate). Async background work, scheduled jobs, and message-consumer transactions all contribute equally to a foreground HTTP transaction. To restrict to user-facing only, filter `WHERE transactionType = 'Web'`.                                                                                           |
| **Aggregation window**        | 5-minute rolling for the live KPI; 1-hour rollup on the trend chart; 1-day rollup for the 7D vsP comparison.                                                                                                                                                                                                                        |
| **Severity threshold**        | All errors counted equally by default. To prioritise P1-only paths, scope the NRQL to `WHERE name LIKE 'Controller/Checkout/%'` or your equivalent.                                                                                                                                                                                 |
| **Browser vs APM scope**      | This card is APM-only (server-side). For client-side errors see [JS Errors / Session](/nerve-centre/kpi-cards/newrelic/js-errors-session) which reads `JavaScriptError` events from Browser. APM error rate of 0.5% with Browser JS errors at 8% means the issue is client-side (a third-party script, a CDN edge, or a CORS rule). |
| **Filtered hosts / services** | `appName IN (...)` is set per-merchant during onboarding to the apps that matter (typically the storefront app, checkout app, and payment service). Background workers and admin tools are excluded by default.                                                                                                                     |
| **Sample basis**              | NRQL on Transaction is sample-corrected for accounts in [event sampling](https://docs.newrelic.com/docs/data-apis/manage-data/high-cardinality/). The percentage stays accurate; the absolute error count may be lower than what server logs show.                                                                                  |
| **Time zone**                 | Account-configured timezone for chart axes; UTC for raw event timestamps.                                                                                                                                                                                                                                                           |
| **Time window**               | `T/7D vsP` (today vs prior 7-day average for the same time-of-day)                                                                                                                                                                                                                                                                  |
| **Alert trigger**             | `>2%`, calibrated to "above the normal day-to-day noise floor of 0.5, 1% on a healthy storefront". Tune up to 3% for B2B integrations where partner-side timeouts inflate the baseline.                                                                                                                                             |
| **Sentiment key**             | `error_rate`                                                                                                                                                                                                                                                                                                                        |
| **Roles**                     | owner, engineering, operations                                                                                                                                                                                                                                                                                                      |

## Calculation

Calculated automatically from your New Relic data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.

## Worked example

A BigCommerce storefront on Cloud Run is showing this card going from 0.6% to 4.1% between 14:05 and 14:20 on 02 May 26. The duty engineer pulls this card up first.

| Time         | NRQL result                     | Interpretation                                |
| ------------ | ------------------------------- | --------------------------------------------- |
| 14:00, 14:05 | 0.6% (60 errors / 9,800 txns)   | Normal noise floor, no action                 |
| 14:05, 14:10 | 1.4% (155 errors / 11,200 txns) | Above noise floor, watch for sustained breach |
| 14:10, 14:15 | 2.8% (348 errors / 12,400 txns) | **Alert fires** (over 2% threshold)           |
| 14:15, 14:20 | 4.1% (525 errors / 12,800 txns) | Sustained, escalate                           |

**What's actually happening:** at 14:08 a deploy went out to the catalogue service. The new build introduced a regression in the product-detail endpoint that returns 503 when SKU has more than 12 variants. About 8% of products meet that condition, so roughly 8% of product-detail page loads now fail.

**Conversion impact translation.** With 12,800 transactions / 5 min and a 4.1% error rate, \~525 customers in 5 minutes hit a broken page. At an average product-detail-to-cart conversion of 12% and an AOV of £85, that's `525 x 0.12 x £85 = £5,355` of cart-add value lost per 5-minute window, or roughly **£1,070/min** of risked GMV. If the rollback takes 25 minutes from alert to deploy, the total exposure is **\~£26.7k** for a single regression.

The Apdex calibration interaction matters here: with `t = 0.5s`, errors that take 8s to surface (the 503 timeout) push customers into the *frustrated* bucket (4 x t = 2s, anything above is frustrated). So Apdex drops from 0.91 to 0.74 at the same time the error rate climbs. The composite [Operational Health Score](/nerve-centre/kpi-cards/newrelic/operational-health-score) drops from 87 to 68, breaching its 70 alert threshold roughly 2 minutes before the error rate alone would.

If the card stayed at 0.6%, the conversation would be different: 0.6% of 12,800 is 77 errors in 5 minutes. Most are background-worker timeouts and 404 from bot crawlers; the customer-facing impact is negligible. Same number, different story, hence the rule "look at trend not absolute level".

## Sibling cards merchants should reference together

| Card                                                                            | Why pair it with Error Rate                                                                                                                            |
| ------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------ |
| [5xx Response Rate](/nerve-centre/kpi-cards/newrelic/5xx-response-rate)         | Subset view: only HTTP 5xx errors. When error rate spikes but 5xx rate doesn't, the cause is application-level exceptions, not infrastructure.         |
| [Errors by Transaction](/nerve-centre/kpi-cards/newrelic/errors-by-transaction) | The drill-down. Tells you *which* endpoint is failing. Open this immediately when error rate breaches threshold.                                       |
| [Top Error Classes](/nerve-centre/kpi-cards/newrelic/top-error-classes)         | Groups by exception class so you can see whether one root cause is driving most of the volume.                                                         |
| [New Error Types (last 24h)](/nerve-centre/kpi-cards/newrelic/new-error-types)  | Detects errors that didn't exist yesterday, the strongest deploy-regression signal.                                                                    |
| [Apdex Score](/nerve-centre/kpi-cards/newrelic/apdex-score)                     | Companion latency-and-satisfaction view. Error rate up + Apdex down = customer-facing problem; error rate up + Apdex stable = background-only problem. |
| [Datadog Error Rate](/nerve-centre/kpi-cards/datadog/error-rate)                | Cross-connector peer. The two should agree within 0.3% during normal periods; gaps over 1% point at probe coverage drift.                              |
| [GA4 Conversion Rate](/nerve-centre/kpi-cards/google-analytics/conversion-rate) | Customer-side outcome. Sustained 3%+ error rate on commerce paths typically drops conversion 15, 30%.                                                  |
| [Shopify Sales / Min](/nerve-centre/shopify/sales_per_minute)                   | Revenue-side outcome. Watch this co-move with error rate during incidents to quantify revenue at risk.                                                 |

## Reconciling against the vendor's own dashboard

**Where to look in New Relic:**

* [APM > Application > Error analytics](https://one.newrelic.com/nr1-core?filters=%28domain%3D%27APM%27%29) for the same NRQL chart in New Relic's native UI.
* [Dashboards](https://one.newrelic.com/dashboards) > pre-built "Error analytics" dashboard.
* [Alerts & AI > Conditions](https://one.newrelic.com/alerts-ai/conditions) to see the alert configuration that backs this card's threshold.

The chart in NR's APM > Errors page should match Vortex IQ to 4 decimal places when both are on the same time-window. If they differ by more than 0.5% on the same window, check the timezone and `appName` filters.

**Why our number may legitimately differ from New Relic's own screens:**

| Reason                                                                                                                                                                                                                                         | Direction of divergence                                 |
| ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------- |
| **Account timezone vs UTC**. NR APM chart axes follow the account timezone; Vortex IQ NRQL runs in UTC. Boundary-period rollups can differ by 0.1, 0.3% on the most recent hour slice.                                                         | Either direction near hour boundaries                   |
| **NRQL retention windows**. Full-resolution `Transaction` events are retained 8 days on standard plans, 13 months on Data Plus. Beyond the retention window, queries return aggregated data with slightly coarser percentage rounding.         | Vortex IQ may show a 0.05, 0.1% drift on >7-day windows |
| **Ingest sampling**. NR samples `Transaction` events on high-cardinality accounts; the percentage stays correct (sample-corrected) but the count differs from raw server logs.                                                                 | Counts in Vortex IQ \< server logs; rates match         |
| **NerdGraph rate limits**. Default 3,000 NRQL points / minute / account. Heavy investigation can stale the card by 30, 60s.                                                                                                                    | Stale, not wrong                                        |
| **Filter scope**. Vortex IQ scopes `appName` to merchant-relevant apps; NR's all-apps default chart includes background workers and admin tools, which can read at 5, 10x the merchant-facing rate without it being a customer-facing problem. | Vortex IQ \< NR raw                                     |

**Cross-connector reconciliation:**

NR APM and [Datadog APM](/nerve-centre/kpi-cards/datadog/error-rate) instrument differently (NR APM agent vs DD trace agent). On the same Express.js or Rails app, the two error-rate numbers should agree within 0.3% during steady state. A 1%+ persistent gap usually means one platform is missing instrumentation on a sub-route (common with framework middleware order changes) or one has a different error-classification rule (NR counts `noticeError()` calls, DD counts unhandled exceptions plus configured 5xx).

<details>
  <summary>Same-metric peers on other connectors</summary>

  | Connector | Card                                                          | Notes                                                                            |
  | --------- | ------------------------------------------------------------- | -------------------------------------------------------------------------------- |
  | Datadog   | [`dd_error_rate`](/nerve-centre/kpi-cards/datadog/error-rate) | Definitional twin via Datadog APM. Should agree within 0.3% on the same service. |
</details>

## Known limitations / merchant FAQs

**New Relic and Datadog disagree on error rate by 1.2%, who's right?**
Probably both, on different scopes. The most common cause is one platform instrumenting a route the other doesn't (a server-sent-events endpoint, a websocket handler, a framework error filter that swallows exceptions before NR sees them). Pick a 5-minute window where the gap is largest and run both queries with the same `appName` filter; if the gap persists, audit each agent's coverage. A persistent 1%+ gap on otherwise identical scope is rare and worth a support ticket on whichever platform looks anomalous.

**Why is my error rate 0% but my customers report errors?**
Three usual causes: (a) the errors are client-side JavaScript, not server-side, see [JS Errors / Session](/nerve-centre/kpi-cards/newrelic/js-errors-session); (b) the application is catching exceptions and not calling `noticeError()`, so APM never sees them, audit the framework's error middleware; (c) the failure is a 4xx (validation, auth) which NR's default config classifies as "expected" rather than "error". Add `error_collector.expected_classes` overrides if 4xx represents real customer pain.

**My error rate jumps every Sunday at 02:00, is something broken?**
Almost certainly a scheduled background job. Check whether your APM scope includes `transactionType = 'Other'` (NR's classification for non-web work). If yes, weekly batch jobs (DB cleanup, report generation) can produce concentrated error volume that doesn't affect customers. Restrict the card to `WHERE transactionType = 'Web'` to filter background work out.

**Apdex math: how do errors interact with Apdex?**
Errors automatically count as *frustrated* in Apdex calculation regardless of duration. So a 200ms error is treated identically to an 8s timeout in the Apdex bucket assignment. This is why a sudden error-rate spike often drops Apdex below 0.5 even when latency p95 looks unchanged: the frustrated bucket fills with fast-failing requests. [NR's Apdex doc](https://docs.newrelic.com/docs/apm/new-relic-apm/apdex/apdex-measure-user-satisfaction/) covers the rule.

**NRQL retention is 8 days but my error trend chart shows 30 days, how?**
NR rolls up `Transaction` data into hourly aggregates after the full-resolution retention window. The 30-day trend chart you see uses the rolled aggregates beyond day 8. Counts and rates remain accurate; what you lose is the ability to drill into a specific minute past day 8.

**Sampling: am I missing real errors?**
On accounts in event sampling, NR keeps a representative subset. Rates are sample-corrected so the percentage you see is accurate; the *raw error count* may be lower than what your server logs show. If you need raw counts (e.g., for billing reconciliation), pair this card with log-side counts from [Error-level Log Rate](/nerve-centre/kpi-cards/newrelic/error-level-log-rate), which is unaffected by event sampling.

**Multi-account: I have a US and EU NR account, can I see one combined number?**
Vortex IQ reads one NR account per integration. To see the combined number, connect both accounts as separate integrations and stack them in the Nerve Centre (the [stack panels](/../05-vortex-mind-runtime) feature averages by transaction count, not arithmetic average, so the combined rate is correctly weighted).

**Ingest cost vs visibility tradeoff: is there a way to keep accuracy and reduce cost?**
Yes. Drop sample rate on non-checkout transactions to 25%, keep checkout at 100%, and keep all error events at 100% (errors should never be sampled, they're rare enough that the cost saving is small). The error rate stays accurate (sample-corrected), checkout flow visibility stays full-fidelity, and ingest cost typically drops 40, 60%.

**Alert tuning playbook: my alert fires too often, what do I tune?**
Three levers in order of usefulness: (a) increase the threshold from 2% to 3% if your baseline noise floor is >1.5%; (b) add a *duration* clause ("must stay above 2% for 5 minutes") to suppress flutter; (c) scope the alert to user-facing transactions only (`WHERE transactionType = 'Web'`). Avoid disabling the alert entirely, an oversensitive alert is fixable, an absent alert costs revenue.

***

### Tracked live in Vortex IQ Nerve Centre

*Error Rate* is one of hundreds of KPI pulses Vortex IQ tracks across New Relic and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English.

[Start for free](https://app.vortexiq.ai/login) or [book a demo](https://www.vortexiq.ai/contact-us) to see this metric running on your own data.
