Heroku Connect is a useful service for synchronizing data between a Salesforce instance and a Heroku Postgres database. It allows developers to work with Salesforce data using familiar SQL tools. However, despite its utility, data sync failures are common and can disrupt your application's functionality, corrupt data, and halt business operations. When a sync fails, it's crucial to have a plan.

This guide is designed to be your go-to resource for a heroku connect error handling guide. We'll walk through how to quickly diagnose, troubleshoot, and resolve the most common errors to keep your data flowing smoothly.

Understanding Common Heroku Connect Errors

The first step in fixing any problem is understanding it. Heroku Connect errors can generally be grouped based on where they happen in the sync process: reading data from Salesforce, writing data back to Salesforce, or issues with the data's consistency. Knowing which category your error falls into will point you toward the right solution.

Write Errors: Failures When Syncing to Salesforce

Write errors occur when Heroku Connect tries to push changes from your Heroku Postgres database to Salesforce [2]. These are often caused by Salesforce rejecting the data for a specific reason.

Common causes include:

• Validation Rule Failures: The data you're sending violates a business rule set up in Salesforce (e.g., a phone number doesn't have the correct format).
• Apex Trigger Exceptions: A piece of custom code (an Apex trigger) in Salesforce fails or uses too many resources while processing the new data.
• Data Type Mismatches: The data format in your database doesn't match what Salesforce expects (e.g., sending text to a number field).
• Missing Required Fields: You're trying to save a record without filling in a field that is mandatory in Salesforce.

Read Errors: Failures When Syncing from Salesforce

Read errors happen when Heroku Connect tries to pull data from Salesforce into your Heroku Postgres database. These issues usually relate to permissions or Salesforce-side limitations.

Common causes include:

• Permission Issues: The Salesforce user account linked to Heroku Connect doesn't have permission to see certain objects or fields [1].
• Salesforce API Limits: Your Salesforce organization has used up its daily allowance of API requests.
• Query Timeouts: A request to get data from Salesforce is too complex and takes too long to complete.

Data Inconsistency and Mismatch Errors

Sometimes, the error isn't about reading or writing but about the state of the data itself. These issues can be tricky because they often appear after the initial sync is complete, leading to conflicts and "orphaned" records that have lost their connections.

Common scenarios include:

• Duplicate Records: The same record exists multiple times, which can happen during an initial data load or if sync rules are not configured correctly [4].
• Record Mismatches: The data in Salesforce and your database become different over time. When an update is attempted, it can fail because the system has an outdated version of the record. These issues can cause operations to break and erode trust in your data, but there are ways to fix Heroku Connect record mismatches.
• Relationship Sync Issues: Syncing records that are related to each other (like an Account and its Contacts) can be challenging. If a parent record fails to sync, its child records can't be linked, leading to errors. These broken links can be frustrating, but you can fix Heroku Connect relationship sync issues.

A Step-by-Step Guide to Troubleshooting Heroku Connect Failures

When an error pops up, having a structured workflow helps you find and fix the problem systematically without feeling overwhelmed.

Step 1: Check the Heroku Connect Dashboard

Your first stop should always be the Heroku Connect dashboard in your Heroku account. The dashboard gives you a quick, high-level view of your data mappings and their sync status. It will clearly show you how many rows are in an error state for each mapping, letting you know where to focus your attention [6].

Step 2: Analyze Logs and Diagnostic Information

For a deeper look, you need to check the logs [5]. Logs provide detailed messages that can pinpoint the exact cause of a failure. You can view a live stream of logs by running the following Heroku CLI command in your terminal:

heroku logs --addon herokuconnect -t

Look for messages that contain words like ERROR or FAILED to find clues about what went wrong.

Step 3: Isolate the Problematic Records

Once you know which mapping has errors, you need to find the specific records that are failing. Heroku Connect makes this easy by adding a special column named _hc_err to each table in your Postgres database. If a row fails to sync, this column will contain the error message from Salesforce.

You can find all failed records for a Contact table with a simple SQL query:
SELECT id, sfid, _hc_err FROM salesforce.contact WHERE _hc_err IS NOT NULL;

Step 4: Address the Root Cause Based on the Error Type

With the error message in hand, you can take targeted action.

• For write errors like "CPU Timeout": This common error often means an Apex trigger in Salesforce is inefficient and taking too long to run [8]. You may need to ask your Salesforce admin to review the code or try processing the records in smaller batches.
• For read errors: These are usually permission-related. Check the Salesforce user profile and permission sets associated with your Heroku Connect user to ensure it has at least "Read" access to all the necessary fields and objects.
• For relationship issues: The key is to make sure parent records are synced successfully before their children. For example, an Account must exist in the system before you can sync a Contact that belongs to it.

Step 5: Retry or Manually Resolve the Sync

After you've fixed the underlying cause, you can tell Heroku Connect to try syncing the failed records again. You can do this from the dashboard. In some cases, you might need to fix the data directly in the Postgres database or in Salesforce before retrying. While effective, these manual Heroku Connect fixes can become tedious and time-consuming.

Beyond Manual Fixes: Automating Error Resolution with Stacksync

While the troubleshooting steps above work, they are reactive and can consume valuable developer time. Constantly digging through logs and manually fixing records is not a scalable strategy.

For teams that need robust, enterprise-grade data synchronization without the headache, Stacksync offers a modern and proactive solution. Stacksync is built from the ground up to handle the complexities of real-time, bi-directional sync, and it comes with powerful error-handling features that address Heroku Connect's limitations.

Key Stacksync features include:

• Advanced Issue Management: A clean, dedicated dashboard to view, manage, and resolve all sync issues without needing to query logs or databases.
• One-Click Retry/Revert: Easily retry failed records or revert unwanted changes with a single click, saving you time and effort.
• Real-Time Alerting: Get instant notifications in Slack, email, or other tools the moment a sync fails, so you can take immediate action.
• Superior Conflict Resolution: Stacksync uses intelligent logic to handle data conflicts that arise in two-way sync scenarios, preventing the common errors that plague Heroku Connect. It provides a reliable way to fix Heroku Connect conflict errors for good.

If you're tired of fighting with sync failures and want a data integration platform that just works, explore what Stacksync can do for you.