"A request to the search index has failed" - OpenSearch(AWS)

[tim.clark]

Hello,

We're experiencing a known compatibility issue between FusionAuth and AWS-managed OpenSearch related to Point-in-Time (PIT) operations during bulk delete operations.

Issue Summary:

Error: SearchEngineRequestFailedException with message "A request to the search index has failed"

Log Pattern: Unable to create point in time on index [fusionauth_user]

Frequency: Occurs during nightly dedupe operations

Impact: Prevents deletion of users via the bulk delete API

Status Code: 503

Environment:

FusionAuth Version: 1.55.1

Search Engine: AWS-managed OpenSearch

Infrastructure: AWS

Background:
We understand this is a known issue with PIT operations against AWS OpenSearch, as documented in FusionAuth community discussions. We've reviewed release notes through version 1.62.1 and haven't found a specific fix for this issue.

Questions:

• Is there a timeline for a fix to address AWS OpenSearch PIT compatibility?
• Are there alternative deletion methods that bypass PIT operations we could use as a workaround?

We'd appreciate any guidance on addressing this issue or information about planned fixes.

Thank you for your assistance.

[mark.robustelli]

@tim-clark Can you please point to the community discussion where this comes up? I could not find it in the issues.

[tim.clark]

@mark-robustelli Hi Mark,

Apologies for the delayed response. We've done some detailed investigation and can share concrete data.

Environment:

• FusionAuth 1.68.0
• search.type=elasticsearch (per your docs, the correct setting for OpenSearch)
• AWS-managed OpenSearch 2.19 (single t3.medium.search node)
• This issue has persisted from at least version 1.55.1 (Dec 2025) through to current 1.68.0

What we observe:

Our deletion job calls the bulk delete API once per user:

DELETE /api/user/bulk?queryString=<email>&hardDelete=true&dryRun=false

On a typical night, 70–210 of these calls are made in rapid succession. A subset fail with:

ERROR io.fusionauth.api.service.search.BaseElasticsearchSearchEngine - Failed to set a Point in Time on index [fusionauth_user]

The response our application receives:

{
"generalErrors": [{"code": "[SearchEngineRequestFailedException]", "message": "A request to the search index has failed. This error is unexpected. Please review the troubleshooting guide..."}],
"status": 503
}

CloudWatch metrics from our OpenSearch domain at the exact moment of failure (29 Jul, 23:12 UTC):

│ Metric                        │ Value                                           │
│ JVM memory pressure           │ 41%                                             │
│ CPU utilisation               │ 11%                                             │
│ Thread pool search rejections │ 0                                               │
│ Thread pool write rejections  │ 0                                               │
│ OpenSearch 5xx responses      │ 0                                               │
│ OpenSearch 4xx responses      │ elevated (spike correlates with deletion burst) │
│ HasUsedPointInTime            │ 0 (PIT never successfully created)              │
│ Request volume                │ ~1,130 in 60 seconds vs normal ~15/min     |    

The OpenSearch node is healthy and not under resource pressure. It appears to be actively rejecting the PIT creation request as a client error (4xx), not failing due to overload. The HasUsedPointInTime CloudWatch metric remains 0 throughout, confirming no PIT is ever successfully established.

We don't have visibility into the raw 4xx response body from OpenSearch — FusionAuth wraps it in the generic SearchEngineRequestFailedException. Our OpenSearch application logs only capture JVM-level warnings, and audit logging isn't enabled.

Questions:

1. What PIT API endpoint does FusionAuth call internally when processing a queryString-based bulk delete? (e.g. POST /{index}/_pit vs POST /{index}/_search/point_in_time)
2. Is it possible to expose the underlying search engine error response in the SearchEngineRequestFailedException? That would help diagnose whether this is a request format issue, a permissions issue,
   or something else specific to AWS-managed OpenSearch.
3. Does FusionAuth use PIT when deleting by explicit userId array rather than queryString? If not, that might give us a workaround?

Thanks,
Tim