Why are my synonyms returning nothing? - search

Question

I am new to Elasticsearch, and right now I am trying to figure out why my synonyms are not returning any results like I expect them to.
I created a custom filter and analyzer for my synonyms file and applied the analyzer to both the _all field and explicitly defined the specialty field to use it as well.
When I search for "specialty": "aids" without the analyzer/tokenizer, it gives me zero results as expected.
However, when I search for "specialty": "aids" with the analyzer/tokenizer, I expect it to give me the same results as searching for "speciality": "retrovirology", which should yields 3 results, but it comes back with nothing.
Is there something wrong with how I am approaching this?
Here are my settings and some sample data:
curl -XDELETE "http://localhost:9200/personsearch"
curl -XPUT "http://localhost:9200/personsearch" -d'
{
"settings": {
"index": {
"analysis": {
"analyzer": {
"XYZSynAnalyzer": {
"tokenizer": "standard",
"filter": [
"XYZSynFilter"
]
}
},
"filter": {
"XYZSynFilter": {
"type": "synonym",
"synonyms": [
"aids, retrovirology"
]
}
}
}
}
},
"mappings": {
"xyzemployee": {
"_all": {
"analyzer": "XYZSynAnalyzer"
},
"properties": {
"firstName": {
"type": "string"
},
"lastName": {
"type": "string"
},
"middleName": {
"type": "string",
"include_in_all": false,
"index": "not_analyzed"
},
"specialty": {
"type": "string",
"analyzer": "XYZSynAnalyzer"
}
}
}
}
}'
curl -XPUT "http://localhost:9200/personsearch/xyzemployee/1" -d'
{
"firstName": "Don",
"middleName": "W.",
"lastName": "White",
"specialty": "Adult Retrovirology"
}'
curl -XPUT "http://localhost:9200/personsearch/xyzemployee/2" -d'
{
"firstName": "Terrance",
"middleName": "G.",
"lastName": "Gartner",
"specialty": "Retrovirology"
}'
curl -XPUT "http://localhost:9200/personsearch/xyzemployee/3" -d'
{
"firstName": "Carter",
"middleName": "L.",
"lastName": "Taylor",
"specialty": "Pediatric Retrovirology"
}'
# Why is this returning nothing?
curl -XGET "http://localhost:9200/personsearch/xyzemployee/_search?pretty=true" -d'
{
"query": {
"match": {
"specialty": "retrovirology"
}
}
}'

Answer 1

You aren't lowercasing anywhere.
Try this:
{
"settings": {
"index": {
"analysis": {
"analyzer": {
"XYZSynAnalyzer": {
"tokenizer": "standard",
"filter": [
"lowercase", "XYZSynFilter"
]
}
},
"filter": {
"XYZSynFilter": {
"type": "synonym",
"synonyms": [
"aids, retrovirology"
]
}
}
}
}
}
Note: you may want to split your index analyzer and search analyzer, and choose only one of them to do the synonyms. Expanding them only during indexing will speed search results.