Intelligent Search - Cross-Searching Internal Knowledge with Amazon Kendra

Learn how to build enterprise search with Amazon Kendra. Covers natural language queries, data source connectors, RAG (Retrieval-Augmented Generation) integration, and when to choose Kendra vs. OpenSearch.

Enterprise Search Challenges and Where Kendra Fits

Enterprise knowledge is scattered across numerous systems - S3, SharePoint, Confluence, internal wikis, FAQ sites, and databases. Traditional keyword search requires users to know the right search terms and can't handle natural language questions like "How do I apply for paid leave?" Amazon Kendra is an ML-based intelligent search service that supports 40+ data source connectors and 14 languages, understands natural language questions, and extracts answers directly from documents. For example, given the question "By when do new employees need to complete their health checkup?", Kendra identifies the relevant section in an internal policy PDF and presents the answer. While OpenSearch (Elasticsearch-based) excels at keyword matching via inverted indexes and aggregation/analytics, Kendra specializes in semantic search powered by natural language understanding (NLU) and machine learning. OpenSearch for engineers doing log analysis and metrics search, and Kendra for non-technical business users searching internal knowledge - the two are complementary.

Data Source Connectors and Index Building

Kendra provides 40+ data source connectors out of the box, enabling no-code connections to major data sources. Supported sources include S3 (PDF, Word, HTML, text), RDS/Aurora (text columns in databases), SharePoint Online, Confluence, Salesforce, ServiceNow, Google Drive, OneDrive, Slack, and GitHub. Custom connector APIs let you integrate proprietary data sources as well. Data source synchronization runs on a configurable schedule (hourly, daily, weekly), automatically reflecting new, updated, and deleted documents in the index. The ACL (Access Control List) auto-import feature pulls access permissions directly from data sources like SharePoint and Confluence, so those permissions are transparently applied to Kendra search results. Documents that User A doesn't have permission to view won't appear in their search results. This transparent access control is a critical feature for enterprise environments with strict security requirements.

Search Features and RAG Integration

Kendra returns search results in three types. Suggested Answer extracts a direct answer from a document with the relevant passage highlighted. FAQ Answer returns answers from a pre-registered FAQ database. Document returns a list of highly relevant documents, similar to traditional search results. For search tuning, you can configure field boosting (weighting specific metadata fields), faceted search (filtering by category, date, author), and synonym dictionaries (thesaurus). Kendra can serve as a retriever in Bedrock's RAG (Retrieval-Augmented Generation) pattern. Kendra searches for relevant documents in response to a user's question, then passes those documents as context to a Bedrock LLM, generating accurate answers grounded in internal knowledge. Kendra's high-precision search results directly improve RAG answer quality. To understand Kendra's model design, related books on Amazon can be helpful.

Pricing and Edition Selection

Kendra offers two editions: Developer Edition and Enterprise Edition. Developer Edition costs $1.125 per hour (approximately $810/month) and supports up to 5 indexes, 40,000 documents, and 4,000 queries per day. It's suitable for development/testing environments and small-scale internal search. Enterprise Edition costs $1.40 per hour (approximately $1,008/month) and supports up to 5 indexes, 500,000 documents, and 8,000 queries per day, with high availability (multi-AZ). Additional document storage and query capacity can be purchased on demand. To reduce costs, you can control index uptime by stopping indexes during nights and weekends. Compared to OpenSearch Serverless, Kendra offers superior natural language search accuracy but at a higher cost. If your search targets are structured log data, OpenSearch is the better fit; for unstructured internal documents, Kendra is the rational choice.

Summary - Guidelines for Using Kendra

Amazon Kendra is an intelligent search service that cross-searches internal knowledge using ML-based natural language understanding. Its key strengths are 40+ data source connectors, transparent access control via ACLs, FAQ functionality, and RAG integration with Bedrock. It's most effective in scenarios where information retrieval is a business bottleneck - reducing internal helpdesk inquiries, improving knowledge management efficiency, and enhancing customer support answer quality. We recommend starting small with Developer Edition, validating the results, and then scaling up to Enterprise Edition.