Reindexing rebuilds an Atlas Search index after its mapping changes. Atlas Search reads relevant source data, reorganizes it under the new mapping, and switches indexes after completion. section 11.3.3
Plan reindexing around these operational considerations:
- Keep serving queries without downtime because the old index remains available while the replacement builds. section 11.3.3
- Reserve free disk space equal to 125% of the current index size before updating it. section 11.3.3
- Expect rebuilds when adding or scaling Search Nodes or when internal mongot changes require index resynchronization. section 11.3.3
Mapping update workflow
1. Change the Atlas Search mapping, analyzer, or indexed fields. 2. Confirm adequate disk capacity. 3. Let Atlas build the new index in the background while the old index serves queries. 4. Use the new index after Atlas completes the seamless transition and removes the old one. section 11.3.3
Listing 11.1 Atlas Search index syntax
{
"analyzer": "<analyzer-for-index>",
"searchAnalyzer": "<analyzer-for-query>",
"mappings": {
"dynamic": <boolean>,
"fields": { <field-definition> }
},
"analyzers": [ <custom-analyzer> ],
"storedSource": <boolean> | {
<stored-source-definition>
},
"synonyms": [
{
"name": "<synonym-mapping-name>",
"source": {
"collection": "<source-collection-name>"
},
"analyzer": "<synonym-mapping-analyzer>"
}
]
}
Use the Atlas Search index syntax to identify mapping and analyzer changes that can trigger reindexing. section 11.3.3
