Search Index creation fails when synonyms list are provided

[Ashik_N_A]

Hi,

I was recently working on mongo atlas free tier (M0 cluster) to create a search index for a POC. I needed to include synonyms in the search index to make it easier to search for similar words. But when I try to create the atlas index I encounter the error below.

1. The error doesn’t provide any extra information on where exactly my document is wrong.

2. I followed the documentation and my synonyms collection follows the format (I even queried to check if there were any invalid docs).

3. I also reduced the collection limit to 10000 as mentioned but it didn’t work either.

4. Here is the JSON for the index configuration:

{
	"mappings": {
		"dynamic": false,
		"fields": {
			"title": {
				"fields": {
					"english": {
						"type": "string"
					}
				},
				"type": "document"
			}
		}
	},
	"synonyms": [{
		"analyzer": "lucene.standard",
		"name": "synonym_mapping",
		"source": {
			"collection": "animeSynCollection"
		}
	}],
	"storedSource": {
		"include": [
			"title.english",
			"bannerImage"
		]
	}
}

[Jason_Tran]

Hi @Ashik_N_A - Welcome to the community

@Ashik_N_A

2. I followed the documentation and my synonyms collection follows the format (I even queried to check if there were any invalid docs).

Could you clarify on the query used to verify if there were any invalid docs?

Additionally, could you provide the source synonym collection (redacting any personal or sensitive information) a long with a few sample documents that are being searched on so that I can try reproduce this behaviour?

Regards,
Jason

[Ashik_N_A]

Hey, thanks for the response. I figured out where the problem was. The query I made only checked the format of synonyms (array), and the string (empty strings) but I forgot to consider symbols.

The document that caused the index build to fail looked like this:

{'_id': ObjectId('6496c27616a431fd95eba537'), 'mappingType': 'equivalent', 'synonyms': ['∞']}

But still, it would be nice if Atlas provided a detailed error, suggesting which document was causing the build to fail (at least the document _id).

Regards,
Ashik

[Jason_Tran]

Glad to hear you found the document causing the error.

@Ashik_N_A

But still, it would be nice if Atlas provided a detailed error, suggesting which document was causing the build to fail (at least the document _id).

Thanks for the feedback above. I agree that it would be helpful if some further information (e.g. _id value could be returned in the error) to help locate the document(s) causing errors. I’ll raise this with the team internally as feedback.

Regards,
Jason