/
Data engineering

Why Heroku Connect Conflict Errors Occur and Stacksync Fixes

Discover how Heroku Connect handles data conflicts and see why Stacksync's real-time sync offers the definitive fix to prevent these errors entirely.

Why Heroku Connect Conflict Errors Occur and Stacksync Fixes

Heroku Connect is a widely used service for synchronizing data between a Salesforce instance and a Heroku Postgres database. For many teams, it serves as the bridge enabling applications built on Heroku to interact with critical business data stored in Salesforce. However, a persistent and costly issue plagues many Heroku Connect implementations: data conflict errors. These conflicts can silently corrupt data, halt critical operations, and force developers to spend valuable hours on manual investigation and intervention.

Understanding Heroku Connect Conflict Errors

In the context of Heroku Connect, a data conflict error occurs when the same data record is modified in both Salesforce and Heroku Postgres simultaneously, before the changes can be synchronized across both systems. This race condition results in two different versions of the same record, and the system is left without a clear directive on which update is the "correct" one.

This often manifests as an UNABLE_TO_LOCK_ROW error, signaling that one process is attempting to write to a record that is already locked by another [7]. The consequences of these errors are severe. They lead to inaccurate data across systems, failed synchronization cycles that disrupt application functionality, and a progressive loss of trust in the data's integrity. These common errors require developers to parse logs to diagnose and fix the underlying issues, wasting significant time and resources [4].

The Root Causes of Data Conflicts in Heroku Connect

Data conflicts in Heroku Connect are not random; they are a direct result of its underlying architecture. Several key factors contribute to their occurrence.

Sync Latency and Polling Intervals

Heroku Connect is not a real-time service. It operates on a polling mechanism, checking for data changes at set intervals. This frequency is typically every 10 minutes, though it can be configured to be shorter for certain plans. This delay creates a significant window where a record can be updated independently in both Salesforce and Postgres before Heroku Connect initiates its next sync cycle. For modern applications where low update times are critical for data integrity, this architectural limitation is a primary source of conflicts [3].

Concurrent Processes and Bulk Updates

Simultaneous operations are another major trigger for data conflicts. Common scenarios include:

  • A sales representative in Salesforce edits a contact record at the same moment an automated process in a Heroku application updates the same contact's status.
  • A bulk data import is executed in Salesforce while a developer runs a script to clean or update records directly in the Postgres database.

When these concurrent processes target the same records within the polling window, conflicts become almost inevitable.

Complex Salesforce Logic and Triggers

Salesforce automations, such as Apex triggers, Flows, and processes from Process Builder, can introduce another layer of complexity that leads to conflicts. For example, Heroku Connect may write an update to a Salesforce record. This write operation can then fire a trigger that immediately modifies the same record again. If this second modification happens before the sync state is fully resolved, it can conflict with a subsequent update from Postgres, leading to a sync failure. In some cases, Salesforce flow triggers can fail entirely when unable to handle the volume of updates from Heroku Connect [5].

How Heroku Connect Handles Data Conflicts: An Imperfect System

Heroku Connect offers rudimentary strategies for conflict resolution, typically allowing users to configure a "Salesforce wins" or "Postgres wins" rule [2]. However, this is not a true resolution; it is a simple overwrite mechanism. The "losing" update is entirely discarded, leading to silent data loss. The data from the losing system is never merged or reconciled it simply vanishes.

This forces a reactive, manual process on development teams. To identify what data was lost, engineers must painstakingly sift through logs to find the overwritten records and attempt to reconcile them. This inefficient process is a major cause of data discrepancies. Over time, these unresolved issues erode data integrity and lead to significant operational challenges. If your team is struggling with these inconsistencies, you may need to Fix Heroku Connect Record Mismatches Using Stacksync Tools.

The Stacksync Solution: Preventing Conflicts with Real-Time, Two-Way Sync

Stacksync is a modern data integration platform architected to proactively prevent conflicts rather than reactively manage them after they occur [1]. It achieves this through a fundamentally different, event-driven approach to synchronization.

Real-Time Sync Eliminates the Conflict Window

Unlike Heroku Connect’s polling mechanism, Stacksync uses an event-driven architecture that synchronizes data changes in milliseconds. When a record is updated in either Salesforce or your database, the change is captured and propagated to the other system almost instantly. This real-time speed eliminates the latency window where conflicting updates can occur. For mission-critical applications that depend on absolute data accuracy, this is not just a feature—it's a requirement. This efficiency also delivers significant operational advantages; you can learn How to Reduce Heroku Connect Costs with Real-Time Bi-Directional Sync and improve your bottom line.

Advanced Issue Management and Visibility

While Stacksync's architecture is designed to prevent conflicts, it also provides superior tools for handling any sync exceptions that may arise. The platform includes a dedicated issue management dashboard that offers clear, real-time visibility into the health of your data sync. Features like single-click retry and revert capabilities empower developers to resolve any issues instantly, without resorting to manual data reconciliation or log diving. With Stacksync, you can Fix Heroku Connect Conflict Errors with Stacksync Sync permanently.

Reliable Sync for Complex Data Relationships

Sync issues often become more frequent and complex when dealing with sophisticated data models involving parent-child relationships. Stacksync is engineered to handle these dependencies gracefully, ensuring that related records are synced in the correct order to maintain referential integrity across systems. This prevents the foreign key errors and orphaned records that often plague Heroku Connect users. To learn more about this specific challenge, see how to Fix Heroku Connect Relationship Sync Issues with Stacksync.

From Risky Polling to Reliable Real-Time Sync

The core problem is clear: Heroku Connect's polling-based architecture inherently creates a high risk of data conflicts, data loss, and operational overhead. Its conflict resolution method overwriting data is not a true solution and often makes the problem worse. The platform's limitations reflect an older approach to data integration that is no longer sufficient for today's real-time business needs [6].

Stacksync provides the definitive fix. By offering a real-time, event-driven, and truly bidirectional sync, it eliminates the root cause of conflicts before they can happen. For businesses that require reliable, scalable, and perfectly accurate data synchronization between Salesforce and their databases, moving to a modern platform like Stacksync is the logical and necessary next step.

→  FAQS
What causes a Heroku Connect conflict error?
A Heroku Connect conflict error happens when a record is updated in both Salesforce and the connected Postgres database at roughly the same time. Because Heroku Connect polls for changes on a delay, it creates a window where two different updates can occur before the system has a chance to sync them, leading to a conflict over which version is correct.
How can you identify Heroku Connect conflict errors?
You can identify conflict errors by checking the Heroku Connect dashboard and reviewing the logs. Look for error messages related to sync failures, such as UNABLE_TO_LOCK_ROW, or investigate records that are in an error state. These are strong indicators that a data conflict has occurred and requires manual review to resolve.
Does Heroku Connect merge conflicting data automatically?
No, Heroku Connect does not merge data. Its conflict resolution setting simply chooses a winner, either "Salesforce wins" or "database wins," and overwrites the other version. This means one of the updates is completely discarded, which can lead to unintentional data loss rather than a true resolution or merge of the conflicting changes.
How does a real-time sync prevent data conflicts?
A real-time sync prevents conflicts by eliminating the delay that causes them. Instead of polling for changes every few minutes, a real-time platform like Stacksync uses an event-driven approach to sync updates in milliseconds. This speed closes the "conflict window," ensuring that changes are reflected in the other system almost instantly and preventing simultaneous, conflicting updates from occurring.
Is Stacksync a better alternative to Heroku Connect for preventing conflicts?
Yes, Stacksync is a superior alternative specifically designed to prevent the conflict errors common in Heroku Connect. Its real-time, bidirectional sync architecture eliminates the latency that causes conflicts. Additionally, its advanced issue management dashboard provides greater visibility and control over the entire sync process, ensuring data remains consistent and reliable across systems.

Syncing data at scale
across all industries.

a blue checkmark icon
14-day trial
a blue checkmark icon
Two-way, Real-time sync
a blue checkmark icon
Workflow automation
a blue checkmark icon
White-glove onboarding
“We’ve been using Stacksync across 4 different projects and can’t imagine working without it.”

Alex Marinov

VP Technology, Acertus Delivers
Vehicle logistics powered by technology