Understanding and Preventing Race Conditions in Workflows

Overview

A race condition occurs when two (or more) workflow actions attempt to update the same contact record at the same time. The workflow logs may show actions as completed, but the contact record might not reflect the changes—such as missing tags, notes, or field updates.

This guide shows how to identify race conditions, what causes them, and how to prevent them by sequencing actions, adding Wait steps, and reducing simultaneous contact updates.

Source Document: Troubleshooting Guide – Understanding and Preventing Race Conditions in Workflows.

What is a race condition?

In BizStackPro workflows, a race condition happens when multiple actions execute at the same time and try to modify the same contact record. Because processing order can be unpredictable, one update can overwrite or block another.

How to identify race conditions

The clearest sign is a mismatch between the workflow execution log and the contact record. If the log says “success,” but the contact didn’t actually update, check whether other actions fired at the same timestamp.

Quick checklist

1. Open the workflow and review the Execution Logs for an affected contact.
2. Find the action that didn’t apply (Add Tag, Update Field, Add Note, etc.).
3. Look for other actions firing at the exact same second.
4. If multiple actions update the same contact at the same timestamp, a race condition is likely.

What causes race conditions?

Race conditions occur when dependent updates run concurrently instead of in a clearly defined order. This can result in overwritten updates, missing tags, or actions that run before the needed data exists.

• Multiple actions (or workflows) updating tags/fields at the same time.
• External integrations/webhooks writing back to the contact concurrently.
• Branches that fire many contact updates in parallel right after a trigger.

Prevent race conditions with Wait steps

The simplest fix is to add a short Wait step between actions that must run in order. This forces sequential processing and gives the first update time to commit before the next one runs.

Step-by-step

1. Identify the collision: find steps that fire at the same timestamp and update the same contact.
2. Insert a Wait action: place it between the conflicting updates.
3. Start with 1 minute: test reliability first, then reduce if needed.
4. Retest: enroll a test contact and confirm updates now show on the contact record.

If 1 minute feels too long, reduce gradually (for example, to 30 seconds) as long as updates remain consistent.

Best practices to avoid race conditions

Use controlled sequencing

Keep dependent updates in a clear order: update data first, then trigger notifications or external calls, then move opportunities or enroll into other workflows.

Use conditional branching

Instead of firing many contact updates at once, split logic with If/Else so only the required branch runs.

Limit concurrent external updates

If you use webhooks or external tools that update the same contact record, stagger calls with Wait steps and avoid multiple “write-backs” at the same moment.

How to verify the issue is resolved

• Logs: key actions should have distinct timestamps instead of firing at the same second.
• Testing: enroll multiple test contacts and confirm updates consistently apply.
• Consistency: compare execution logs to the contact record and verify they match.
• Overlap: review triggers/schedules so multiple workflows aren’t updating the same data simultaneously.