Troubleshooting the Data Quality Features

Alation Cloud Service Applies to Alation Cloud Service instances of Alation

This section outlines common issues and troubleshooting guidance for the Alation Data Quality application. Use this guide to identify the root cause of a problem and take appropriate steps to resolve it.

Alation Data Quality Monitor

Monitor Setup Wizard does not display Recommendations

The setup wizard fails to show recommended tables, columns, or AI-powered suggestions.

Problem

• Monitor setup wizard does not display any recommended tables or columns.

• AI recommendations do not appear after selecting a table.

Causes

• Cataloged metadata is incomplete or outdated.

• Lineage data is not available or turned off.

• Data source is not profiled or scanned recently.

Solutions

• Ensure metadata extraction has run successfully on the connected data source.

• Confirm table- and column-level lineage is enabled for relevant sources.

• Re-run metadata extraction or profiling jobs if required.

Monitors Not Running as Scheduled

A monitor does not execute at its designated time, and no recent results are visible.

Problem

• Monitor has not run at the scheduled time.

• No recent check results appear in the UI.

Causes

• Monitor schedule is misconfigured.

• Backend job failure or delay.

• Temporary outage of the service.

Solutions

• Go to the Monitor page and verify the schedule.

• Manually trigger a monitor run to test execution.

• Contact Alation Support if the issue persists across multiple monitors.

Check Configuration

Data Quality Checks return “Error” status

Checks display an “Error” status instead of reporting “Pass” or “Fail” results.

Problem

Checks return “Error” instead of “Pass” or “Fail”.

Causes

• Invalid SQL syntax in custom checks (CTE or SQL).

• Missing access privileges for the service account.

• Data source has moved, schema or table renamed.

Solutions

• Verify SQL and CTE logic; test queries in the data source directly.

• Check service account access to the target schema, table, or column.

• Confirm data source configuration is up-to-date.

• Re-create the check using valid references.

YAML Validation Errors

The system displays errors when you attempt to add or update check configurations using YAML.

Problem

You cannot add check configuration through YAML syntax.

Solution

Validate your YAML syntax. Check errors displayed on user interface (for example, missing indentation, undefined keys). As an alternative, you can switch back to UI mode until the errors are resolved.

Data Quality Score Not Displaying

An asset shows a double dash -- instead of a numerical score.

Problem

Table shows -- instead of a score in the Assets tab

Causes

• No active or enabled checks on the table.

• No successful check executions were recorded.

Solutions

1. Add at least one active check to the table.

2. Run the monitor at least once to populate results.

3. Ensure there are no errors in the check definitions.

Columns Missing from UI

Expected columns do not appear in the list when you are configuring a check.

Problem

Some expected columns do not appear while configuring the checks.

Cause

Columns are not covered in the extracted metadata.

Solution

Refresh the metadata for the table.

Inconsistent Results Across Monitors

Identical data quality checks return different results when run in different monitors.

Problem

You are reviewing the results of the same data quality check (for example, a “Null Check” on a specific column) that has been added to multiple monitors.

Cause

The primary reason for discrepancies between identical checks is a difference in data freshness or synchronization across the environments being monitored.

• The tables or columns being checked may have different data recency or update frequencies.

• One environment may have processed a more recent batch of data than the other, causing the check to evaluate different datasets.

Solution

1. Check the Last Updated or Freshness metadata for the tables in each environment to confirm they contain the same data state.

2. Review and align the execution schedules of the monitors.

3. Ensure that monitors run after the upstream data pipelines have finished loading data in their respective environments.

4. Confirm that any row-level filters or parameters used in the checks are exactly the same in both monitor configurations.

UI Lag or Unresponsiveness

The Alation Data Quality application pages load slowly or time out.

Problem

You experience significant delays when navigating between monitors or loading the Data Quality dashboard.

Causes

This performance lag is often related to the volume of data being processed or local browser limitations.

• A very large number of checks or monitors are assigned to a single table.

• There are local browser memory or resource constraints.

Solutions

1. Split large monitors into smaller ones by data domain.

2. Use Google Chrome or Microsoft Edge latest versions and clear browser cache.

3. Restart browser and retry in Incognito mode.

Microsoft Teams

Microsoft Teams Notifications Issues

Microsoft Teams notifications are either missing from the dropdown or are not being delivered.

Problem

The specific Microsoft Team you want to use for notifications is not available in the Team dropdown menu.

Cause

The Alation application has not been properly set up for that Team.

Solution

Ensure that a Team Owner has followed all the prerequisite steps, including installing the app, logging into Alation via the app, and adding the app to the specific Team.

Channel Not Receiving Alerts

Notifications are configured, but the channel does not receive any alerts.

Problem

You have configured the notifications but alerts are not showing up in the channel.

Cause

Permission issues with Alation.

Solution

1. Verify that the Alation app still has the necessary permissions in Teams and has not been removed from the Team.

2. Check the monitor’s run history in Alation to confirm that it has run and failed since the notification was configured.

Slack Notifications

Slack Doesn’t Appear in the Notifications

While configuring notifications, you do not see Slack listed.

Problem

You do not see an option for Slack or any channels in the Notifications dropdown.

Cause

The Alation Slack application has not been installed or configured for your Slack workspace.

Solution

Contact your Slack Workspace Administrator to ensure they have installed the app and connected it to your Alation instance.

Alation Anywhere for Slack is Already Installed

You receive an error that Alation Anyware for Slack is already installed.

Problem

When you try to install the Slack app, you get an error: “Alation Anywhere for Slack is already installed on this Slack workspace for another Alation instance.”

Cause

Your Slack workspace is already connected to a different Alation instance. A Slack workspace can only be connected to one Alation instance at a time.

Solution

To connect to a new instance, you must first uninstall the app from the current Slack workspace and then repeat the installation process.

1. In Slack, click on your Workspace name in the top left.

2. Go to Tools & settings > Manage apps.

3. Find the “Alation-DQ” app in the list of installed apps.

4. Navigate to the app’s Configuration tab and select the option to Remove app.

Data Quality Standards

Standard is Not Visible in the Library

You have created a Data Quality Standard, but it does not appear in the library and cannot be selected for bulk application.

Problem

You are in the Standards library or the Apply DQ Standards monitor workflow, but a specific standard you recently created is missing from the list. This prevents you from enforcing these rules across your data assets.

Cause

The standard is currently in a Draft state. Data Quality Standards remain in Draft mode until explicitly published, making them visible only to the creator or designated owners.

Solution

1. Navigate to the Data Quality application and click the Standards tab.

2. Locate the standard with the Draft status icon.

3. Click on the standard to open the editor.

4. Review the configuration and click Publish.

Standard Fails to Save Due to Threshold Errors

The UI displays an error and prevents saving when you attempt to finalize a standard’s check thresholds.

Problem

You are in the Create Check section within the Configure Checks step of the Standards editor. When you click Save, a red banner appears indicating a threshold error, and the check is not added to the standard.

Cause

The defined Severity Levels (Pass, Warn, or Fail) contain overlapping or conflicting numerical ranges. For example, a “Warning” cannot be set for a value range that is already designated as a “Failure”.

Solution

1. In the Create Check section, scroll down to the Threshold section.

2. Review the numerical values for each severity level (Pass, Warn, Fail).

3. Adjust the ranges so that each value belongs to only one category (for example, Fail if >10, Warn if 5-10, Pass if <5).

4. Click Save again to validate the logic.

Column Discovery Returns No Results

Searching for columns during the bulk application workflow yields no matches.

Problem

You are in Step 2 (Select Objects) of the Apply DQ Standards monitor workflow. You enter keywords or select a domain in the search bar, but the results table remains empty.

Cause

The search criteria do not match the physical metadata or the cataloged domain assignments. Either the keyword is not an exact match for the column name, or the domain filter is targeting assets that haven’t been assigned that domain in the catalog.

Solution

1. Verify the exact spelling of the column names in table on the catalog page.

2. If searching by domain, navigate to the target table in the catalog and ensure the domain field is correctly populated.

3. Return to the Apply DQ Standards workflow and re-enter the corrected search terms.

Target Columns are Grayed Out and Cannot Be Selected

Specific columns appear in the search results but cannot be checked or selected.

Problem

During Step 2 (Select Objects) of the Apply DQ Standards workflow, some columns are visible but their checkboxes are inactive or grayed out.

Cause

The column already has an active check derived from the exact same standard. Alation Data Quality prevents duplicate applications of the same standard logic to the same asset to avoid conflicting data health signals.

Solution

1. No action is required to apply the standard.

2. To modify the existing logic for that column, navigate to the Data Quality check for the specific catalog asset and edit the check directly.

Application Timeout During Bulk Deployment

The system fails to complete the application process or hangs when you try to deploy a standard to a large number of assets.

Problem

You are in the final step of the Apply DQ Standards workflow. After clicking Create, the UI displays a loading spinner for several minutes, or you receive a “Request Timeout” error. The individual checks are not created, and the workflow does not return you to the monitor list.

Cause

You are attempting to apply a standard to thousands of columns simultaneously, which can take several minutes and overload the system.

Solution

1. Navigate back to the Apply DQ Standards workflow.

2. In Step 2 (Select Objects), use the sidebar filters to reduce the number of selected assets.

3. Apply the standard in smaller, manageable increments (for example, by selecting one specific Schema or Data Source at a time).

4. Repeat the process for the remaining schemas once the first batch is successfully deployed.

High Warehouse Compute Costs

Running checks derived from a standard is incurring unusually high costs on your data warehouse.

Problem

Your data warehouse billing (for example, Snowflake Credits or BigQuery bytes processed) shows a significant spike in usage following the deployment of a new DQ Standards Monitor.

Cause

The checks are performing a full-table scan, evaluating the entire historical depth of the tables rather than focusing on a restricted, operationally relevant timeframe.

Solution

1. Navigate to the Data Quality application and locate the monitor associated with the standard.

2. Click on the monitor and go to Step 3 (Apply Filters).

3. Enable the Global Time Filter toggle.

4. Select a Partition Column (for example, created_at or updated_at) and set a window, such as the Last 7 days.

5. Click Save. Future executions will only process the rows within that 7-day window, significantly reducing compute load.

Standard-Based Checks Fail to Execute

You have successfully applied a standard and configured a monitor, but no results or scores are appearing for the target columns.

Problem

You navigate to the Data Quality tab of a catalog asset or the Monitor page. The checks are listed, but they show a “Never Run” status or have no recent execution timestamps.

Cause

The checks created by a standard rely entirely on the monitor Schedule of the parent data source. If the monitor is created but the schedule is not enabled or activated, the logic remains idle.

Solution

1. Navigate to the Data Quality application and click the Monitors tab.

2. Find the monitor you created for the standard and check the Schedule column.

3. If the schedule is set to None, click the monitor name to edit it.

4. In Step 5 (Configure Monitor), set a frequency (for example, Daily) and a specific run time.

5. Save your changes. The checks will now execute automatically according to the new schedule.

Quality Results Do Not Reflect Standard Updates

You modified a standard in the library, but the checks already in the field are still using the old logic or thresholds.

Problem

You updated a standard’s logic (for example, changed a threshold from 10 to 5) and published it. However, when you view a column where that standard was already applied, the check still reflects the old threshold of 10.

Cause

During the update process in the Standards library, the option to Apply to new columns only was selected. This leaves all existing checks running on the legacy version of the standard to prevent unintended changes to historical scores.

Solution

1. Return to the Standards library and select the standard you modified.

2. Click Edit and make a minor change to trigger the publication dialog.

3. When the prompt appears, explicitly select the option to Reapply to All Existing Assets.

4. Confirm the action. Alation Data Quality will sync the new logic to all existing monitors.