---
title: Field mapping mismatch
description: cross-project search machine learning datafeeds merge search results across linked projects. When the same field name maps to incompatible types in different...
url: https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/7403/troubleshoot/elasticsearch/machine-learning/cps-datafeed-field-mapping-mismatch
products:
  - Elastic Cloud Serverless
  - Elasticsearch
  - Machine Learning
applies_to:
  - Elastic Cloud Serverless: Preview
  - Elastic Stack: Unavailable
---

# Field mapping mismatch
cross-project search machine learning datafeeds merge search results across linked projects. When the same field name maps to **incompatible types** in different projects, anomaly detection jobs may exclude the field, fail to start, or drop a conflicting project from the run depending on whether the field is optional or required (such as the time field).
<tip>
  If you can't find your issue here, explore the other [troubleshooting topics](https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/7403/troubleshoot) or [contact us](/elastic/docs-content/pull/7403/troubleshoot#contact-us).
</tip>


## Diagnose field mapping mismatch

**Error messages**
Search for these exact patterns in machine learning job **Messages** or API error responses.
*Optional field conflict (datafeed continues; field may be dropped):*
```txt
Cross-project field conflict for datafeed `[my-datafeed]`: field `[status]` has incompatible types across linked projects — `keyword` in `[prod-us]`, `long` in `[prod-eu]`. Align index mappings across projects or narrow `project_routing` to projects with a consistent schema.
```

*Required time field — creation fail-fast:*
```txt
Cannot run datafeed `[my-datafeed]`: required time field `@timestamp` has conflicting types across projects in scope — `date` in `[prod-us]`, `long` in `[prod-eu]`. Fix mappings so `@timestamp` uses the same type in every project in scope, or exclude the conflicting project(s) via `project_routing`.
```

*Required time field — mid-run project exclusion:*
```txt
Datafeed `[my-datafeed]` excluded project `[prod-eu]` from this run: required time field `@timestamp` has conflicting types — `date` in `[prod-us]`, `long` in `[prod-eu]`. Fix mappings in `[prod-eu]` to resume searching it, or remove it from `project_routing`.
```

Replace bracketed placeholders with your datafeeds id, field names, project aliases, and types.
**Compare mappings across projects**
Run [field capabilities](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-field-caps) on the datafeed indices in each project in scope. Use qualified index names when projects differ:
```json
```

Compare `type` (and `metadata`) for each field across projects. `date` and `date_nanos` are treated as compatible for the time field; other type pairs are not.
**Check machine learning job Messages**
Open **ML → Anomaly Detection → your job → Messages** for mapping conflict warnings or project-exclusion errors. Mid-run exclusions can be easy to miss if the datafeeds stays `started`.

## Resolve field mapping mismatch

**Align index mappings (recommended)**
Standardize the conflicting field to the same type in every linked project — especially `@timestamp` (use `date` with a consistent format). Update index templates or reindex where needed, then update or restart the datafeeds.
**Narrow `project_routing`**
If you cannot align mappings immediately, limit scope to projects with a consistent schema:
```json

{
  "project_routing": "_alias:prod-us"
}
```

For a single conflicting project, remove it from routing instead of dropping the entire cross-project scope.
**Verify recovery**
After mapping fixes or routing changes:
```json
```

Confirm the datafeeds searches the intended projects and **Messages** no longer report field conflicts. For time-field fail-fast errors, start the datafeeds again after mappings are aligned.
If conflicts persist after aligned `_field_caps` results, contact Elastic support with field names, project aliases, and the conflict message text.