Components & Best Practices for Map/Reduce Scripts

Components of Map/Reduce Scripts

1. Map Phase

• Purpose: To process individual records and transform data.
• Function: Processes each record retrieved by a search or data input, usually in parallel, and emits intermediate results for the Reduce phase.
• Implementation: Implemented using the map() function.

2. Reduce Phase

• Purpose: To aggregate and further process the data emitted by the Map phase.
• Function: Combines the intermediate results, performs calculations, and generates the final output.
• Implementation: Implemented using the reduce() function.

3. Summarize Phase

• Purpose: To summarize the overall processing, handle errors, and log results.
• Function: Provides a summary of the processing job, including statistics and any issues encountered.
• Implementation: Implemented using the summarize() function.

Best Practices for Map/Reduce Scripts

1. Optimize Performance

• Minimize Data Volume: Use filters and pagination to handle large datasets efficiently.
• Batch Processing: Process data in manageable batches to avoid exceeding governance limits.

2. Error Handling

• Robust Error Logging: Implement detailed error logging and handling in the summarize function to manage issues effectively.
• Retry Logic: Consider adding retry logic for transient errors or issues.

3. Efficient Data Handling

• Use Context Objects: Leverage the context object to pass data efficiently between Map and Reduce phases.
• Avoid Long Operations: Ensure that processing logic is optimized to avoid long-running operations that could impact performance.

4. Manage Governance Limits

• Monitor Usage: Regularly check script governance usage and manage limits using the runtime module.
• Break Down Tasks: If necessary, break down large tasks into smaller scripts or scheduled scripts to comply with governance limits.

5. Documentation and Maintenance

• Document Code: Provide clear comments and documentation within your scripts to facilitate maintenance and updates.
• Regular Updates: Review and update scripts periodically to ensure compatibility with NetSuite updates and business changes.