Migrating existing Logic Apps Workflow Logs Accross multipe storage accounts

Question

Hi,

We are trying to adjust a Logic Apps resource so that it writes its logs to multiple storage accounts, as described in this tutorial: https://techcommunity.microsoft.com/blog/integrationsonazureblog/scaling-logic-app-standard-for-high-throughput-scenarios/3866731

However, the tutorial states that this approach only works for new resources, before any workflows are added. Currently, we have a rather suboptimal setup where multiple busy Logic Apps resources write to a single storage account. This causes additional latency due to throttling on storage write operations.

We want to resolve this by configuring each Logic Apps resource to use three storage accounts for writing logs. We have updated the environment variables and the host.json, but the logs are still being written to the default storage account and are not being spread across the three storage accounts.

Is there a way to make this work for an existing Logic Apps project that already contains workflows?

Answer 1

Hi ,

Thanks for reaching out to Microsoft Q&A.

No. This does not work for existing Logic Apps Standard resources.

Multi-storage account logging is evaluated only at resource creation time.

Once a Logic Apps Standard resource has any workflows created, the storage bindings are locked.

Updating environment variables or host.json later is ignored for log storage routing.

This is by design, not a bug.

What actually works ?

1. Recreate the Logic Apps resource
   • Create a new Logic Apps Standard with the multi-storage configuration upfront.
   • Migrate workflows (ARM/Bicep export + import).
   • This is the only supported way to use multiple storage accounts for logs.
2. One storage account per Logic Apps resource
   • Still supported for existing apps.
   • Reduces throttling without rebuilding everything.
3. Move diagnostics out of storage
   • Send logs to Log Analytics / Application Insights.
   • Storage accounts are a poor choice for high-throughput logging.
4. Scale storage, not hack routing
   • Premium storage, separate accounts per app, avoid shared accounts.
   • Trying to force log fan-out post-creation will not work.

If you need multi-storage logging, you must recreate the Logic Apps Standard resource. There is no supported retrofit path for existing projects.

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