Data of type AzureDiagnostics is being dropped due to incorrect format at lineOffset: 247. Exception message: Unexpected character encountered while parsing value: \. Path 'records[247].resultDescription', line 1, position 155215.

Question

Data of type AzureDiagnostics is being dropped due to incorrect format at lineOffset: 247. Exception message: Unexpected character encountered while parsing value: \. Path 'records[247].resultDescription', line 1, position 155215.

merlingadz 5

The Diag setting of my Postgresql seems to send wrong data to my log analytics workspace:

https://learn.microsoft.com/en-us/answers/questions/1701891/log-analytics-workspace-reports-10-warnings

Data of type AzureDiagnostics is being dropped due to incorrect format at lineOffset: 1. Exception message: Unexpected character encountered while parsing value: . Path 'records[1].resultDescription', line 1, position 1081.

Data of type AzureDiagnostics is being dropped due to incorrect format at lineOffset: 247. Exception message: Unexpected character encountered while parsing value: . Path 'records[247].resultDescription', line 1, position 155215.

Does anyone have a work arround in order to solve this issue ?

Sai Raghunadh M 4,575 Reputation points Microsoft External Staff Moderator

2025-02-27T17:22:02.7766667+00:00

HI @Nicolas Lhoir

Just checking in to see if the below answer provided by @ Vinodh247 helped.

If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.
Vinodh247-1375 44,801 Reputation points Volunteer Moderator

2025-02-28T05:30:23.9233333+00:00

@merlingadz

Please feel free to 'Accept as Answer' and click the 'Upvote'(Thumbs-up) button. This helps the community by allowing others with similar queries to easily find the solution.

1 answer

Your answer

Sai Raghunadh M 4,575 Reputation points Microsoft External Staff Moderator

2025-02-27T17:22:02.7766667+00:00

HI @Nicolas Lhoir

Just checking in to see if the below answer provided by @ Vinodh247 helped.

If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.
Vinodh247-1375 44,801 Reputation points Volunteer Moderator

2025-02-28T05:30:23.9233333+00:00

@merlingadz

Please feel free to 'Accept as Answer' and click the 'Upvote'(Thumbs-up) button. This helps the community by allowing others with similar queries to easily find the solution.

Answer 1

Vinodh247-1375 44,801 Volunteer Moderator

Hi ,

Thanks for reaching out to Microsoft Q&A.

This problem has been reported by other users as well, suggesting it might be related to the diagnostic settings of azure services, including azure database for PostgreSQL.

Potential Workarounds:

Inspect Diagnostic Settings:
- Review the diagnostic settings configured for your Azure Database for PostgreSQL. Ensure that the logs are being sent in the correct format and that all necessary categories are selected appropriately.
Validate JSON Formatting:
- The error message indicates a JSON parsing issue. Verify that the logs being generated and sent to Log Analytics are properly formatted JSON. Malformed JSON can lead to ingestion errors.
Check for Recent Changes:
- Determine if any recent updates or changes were made to your PostgreSQL instance or its diagnostic settings around the time the errors began. Reverting or adjusting these changes might resolve the issue.
Monitor Log Analytics Workspace:
- Utilize the _LogOperation function in your Log Analytics workspace to identify and analyze the errors. Running the following query can help pinpoint the source of the issue.
  
  _LogOperation | where Level in ("Error", "Warning") | summarize arg_max(TimeGenerated, *) by Level, Resource=_ResourceId, Computer, Category, Operation, Details=Detail | project TimeGenerated, Level, Category, Computer, Details

If nothing worked, raise a support case with azure.

https://learn.microsoft.com/en-us/answers/questions/1701891/log-analytics-workspace-reports-10-warnings

Please feel free to click the 'Upvote' (Thumbs-up) button and 'Accept as Answer'. This helps the community by allowing others with similar queries to easily find the solution.

merlingadz 5 Reputation points

2025-02-28T08:34:27.3766667+00:00

Actually, I did not find my way to solve this issue:

1 & 2 : it's a PaaS config where I want to forward all logs and metrics

3: it's a new implementation

How can I identify which resource send this faulted message ?
Vinodh247-1375 44,801 Reputation points Volunteer Moderator

2025-03-01T16:26:06.3733333+00:00
Since this is a new implementation and you want to forward all logs and metrics from an Azure Database for PostgreSQL PaaS to Log Analytics Workspace, you need to identify the resource sending malformed messages.

Steps to Identify the Faulty Resource Sending Malformed Logs:

Query Log Analytics Workspace for Errors

You can use KQL in azure log analytics to filter logs and identify which resource is causing the issue.

Run the following query in Log Analytics:

AzureDiagnostics | where isnotempty(resultDescription) | where resultDescription contains "Unexpected character" | project TimeGenerated, ResourceId, Resource, Category, resultDescription | order by TimeGenerated desc

This query will:

Look for entries in AzureDiagnostics where there is an issue in resultDescription.

Identify if there are any messages containing "Unexpected character".

List the ResourceId, Resource Name, and Category associated with the faulty message.

If this query doesn't return anything, expand your search with:

AzureDiagnostics | where isnotempty(resultDescription) | where resultDescription contains "parsing value" | project TimeGenerated, ResourceId, Resource, Category, resultDescription | order by TimeGenerated desc

Investigate Diagnostic Settings in Azure Portal

Navigate to Azure Monitor > Diagnostic Settings.

Check the diagnostic settings for PostgreSQL.

If multiple resources (Application Insights, other databases, VMs) are sending logs to the same Log Analytics Workspace, check their settings.

Disable each one temporarily and observe if the error disappears.

Use Azure Monitor to Trace Log Errors

Go to Azure Monitor > Logs > AzureDiagnostics.

Set up Alerts for parsing errors (this can help in live monitoring).

If a specific query or function is causing an error, check the logs related to that operation.

If you identify a specific resource causing the issue, try disabling that resource's diagnostic settings temporarily.

If PostgreSQL itself is generating malformed logs, consider opening a support ticket with Microsoft because PaaS diagnostic logs should be formatted correctly by default.
Sai Raghunadh M 4,575 Reputation points Microsoft External Staff Moderator

2025-03-03T00:30:53.29+00:00

HI @HI @Nicolas Lhoir

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
Toivo Voll 6 Reputation points

2026-09-28T11:55:51.7533333+00:00
Support case seems to be the only answer. We have no databases, but are getting the same error. There is no information about the resource or the diagnostic setting or the message itself in the error message, even when I query the raw message.

_LogOperation | where Level in("Error", "Warning")