--- title: Scope alert thresholds to specific instances source: https://docs.newrelic.com/docs/alerts/create-alert/examples/scope-alert-thresholds-specific-instances --- You can set alert [thresholds](https://docs.newrelic.com/docs/using-new-relic/welcome-new-relic/get-started/glossary#alert-threshold) that trigger when they're breached by any of your Java app's instances. Scoping the condition to instances of your app is helpful for detecting anomalies that occur only in a subset of your app's instances. These sorts of anomalies are easy to miss for apps that aggregate metrics across a large number of instances. By looking at each instance, you can more quickly identify where potential problems are originating. ## Example [#example] In this example, you set up a policy for a Java app with three instances. You want to open an alert event when the condition's critical threshold for any instance's error rate is greater than .02% **for at least** five minutes. During a five-minute time period the three instances have these error rates: | **App instance** | **4:45pm** | **4:50pm** | **alert event opened?** | | ---------------- | ---------- | ---------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | A | 0.00% | 0.00% | No. This instance remained below the target threshold the entire time. | | B | 0.02% | 0.03% | Yes. The alert threshold exceeded the 0.02% threshold for this instance for at least five minutes. | | C | 0.10% | 0.00% | No. The threshold value must be breached for [at least five consecutive minutes](https://docs.newrelic.com/docs/alerts/new-relic-alerts/configuring-alert-policies/define-thresholds-trigger-alert#threshold-triggers) to open an alert event. However, if you had set the threshold for **at least once** in five minutes, then the threshold value must be breached [at least once](https://docs.newrelic.com/docs/alerts/new-relic-alerts/configuring-alert-policies/minimum-maximum-values#violation) during the five-minute period. | ## Create instance-based alert condition [#procedure] /\* \*/ To create a policy that triggers notifications for alert events by your app's individual instances: 1. Follow the [basic workflow process](https://docs.newrelic.com/docs/alerts/new-relic-alerts/configuring-alert-policies/alert-policy-workflow#alert-policy-process) to set up a policy. 2. When creating a [condition](https://docs.newrelic.com/docs/alerts/create-alert/create-alert-condition/alert-conditions) (step 2), select [**APM**](https://docs.newrelic.com/docs/alerts/new-relic-alerts/configuring-alert-policies/select-product-targets-alert-condition). 3. Select **Application metric** as the type of condition. 4. To evaluate alert threshold alert events **individually** for each of the app's selected instances, select **Scope to Java application instances**. 5. Select **Next, select entities**, then identify one or more apps for this condition. 6. Optional: Change the time when alerts will force-close the alert events (default is 24 hours). 7. Use **By condition** or **By condition and signal** [alert event preference](https://docs.newrelic.com/docs/alerts/organize-alerts/specify-when-alerts-create-events). 8. Continue the rest of the [policy workflow process (step 3)](https://docs.newrelic.com/docs/alerts/new-relic-alerts/configuring-alert-policies/alert-policy-workflow#alert-policy-process). > #### 💡 TIP > > To open alert events based on the **average** of all instances for your apps, select **Scope to the application** instead of **Scope to Java application instances**. ## Use "By condition" alert event preference [#targets] When setting the [alert event preference](https://docs.newrelic.com/docs/alerts/organize-alerts/specify-when-alerts-create-events) for policies containing instance-based conditions, we recommend that you select **By condition** instead of **By condition and signal**. Although apps are the selected entities for this condition, we evaluate each JVM as a separate entity. If you set your **Alert event preference** to **By condition and signal**, a separate alert event will be opened for each JVM that breaches the critical threshold. When an app fails across multiple JVMs, this can lead to alert "fatigue" and frustration. ## Use REST API for instance alerts To create instance-based [alert conditions with the New Relic REST API](https://docs.newrelic.com/docs/alerts/new-relic-alerts/rest-api-alerts/manage-entities-alerts-conditions), include these items with your REST API call: - Your [API key](https://docs.newrelic.com/docs/apis/rest-api-v2/getting-started/introduction-new-relic-rest-api-v2#api_key). - The numeric [`entity_id`](https://docs.newrelic.com/docs/using-new-relic/welcome-new-relic/get-started/glossary#entity) for the [entity](https://docs.newrelic.com/docs/using-new-relic/welcome-new-relic/get-started/glossary#entity) being monitored - The [`condition_id`](https://docs.newrelic.com/docs/using-new-relic/welcome-new-relic/get-started/glossary#alert-condition) (available from the API Explorer: [**Alerts Conditions > GET > List**](https://api.newrelic.com/docs/#/Alerts%20Entity%20Conditions)) - The `entity_type` (set to `"application"`) - The `condition_scope` (set to `"instance"` for a Java application instance or `"application"` for a Java app) Here is an example of the API request format and JSON response. **Instance alert API call** Use this format for your API call: ````sh curl -X PUT 'https://api.newrelic.com/v2/alerts_entity_conditions/12345.json' \ -H 'X-Api-Key:$API_KEY' -i \ -H 'Content-Type: application/json' \ -G -d 'entity_type=application&condition_id=234567' ``` * Replace `$API_KEY` with your [API key](/docs/apis/rest-api-v2/getting-started/introduction-new-relic-rest-api-v2#api_key). ```` **Instance alert JSON response** The API returns the response as JSON. ````json { "condition": [ { "id": 234567, "type": "apm_app_metric", "name": "demo", "enabled": true, "entities": [ 12345 ], "metric": "apdex", "condition_scope": "instance", <---<<< scope indicator "violation_close_timer": 24, "terms": [ { "duration": "5", "operator": "above", "priority": "critical", "threshold": "1", "time_function": "all" } ] } ] } ``` ````