Merge pull request #281354 from JeffreyWolford/patch-23

Update azure-monitor-agent-custom-text-log-migration.md

Author: Stacyrch140

articles/azure-monitor/agents/azure-monitor-agent-custom-text-log-migration.md

@@ -5,24 +5,29 @@ ms.topic: conceptual
 ms.date: 05/09/2023
 ---
 
-# Migrate from MMA custom text log to AMA DCR based custom text logs
-This article describes the steps to migrate a [MMA Custom text log](data-sources-custom-logs.md) table so you can use it as a destination for a new [AMA custom text logs](data-collection-log-text.md) DCR. When you follow the steps, you won't lose any data. If you're creating a new AMA custom text log table, then this article doesn't pertain to you.
+# Migrate from MMA custom text table to AMA DCR based custom text table
+This article describes the steps to migrate a [MMA Custom text log](data-sources-custom-logs.md) table so you can use it as a destination for a new [AMA custom text logs](data-collection-log-text.md) DCR. If you're creating a new AMA custom text table, then this article doesn't pertain to you.
 
-> Note: Once logs are migrated, MMA will not be able to write to the destination table. This is an issue for the migration of production system that we are actively working.
->
 
-## Background
-MMA custom text logs must be configured to support new features in order for AMA custom text log DCRs to write to it. The following actions are taken:
-- The table is reconfigured to enable all DCR-based custom logs features.
-- All MMA custom fields stop updating in the table. AMA can write data to any column in the table. 
-- The MMA Custom text log can write to noncustom fields, but it will not be able to create new columns. The portal table management UI can be used to change the schema after migration.
+> [!Warning]
+> Your MMA agents won't be able to write to existing custom tables after migration. If your AMA agent writes to an existing custom table, it is implicitly migrated.
+
 
-## Migration procedure
+## Background
+You must configure MMA custom text logs to support new DCR features that allow AMA agents to write to it. Take the following actions:
+- Your table is reconfigured to enable all DCR-based custom logs features.
+- Your AMA agents can write data to any column in the table. 
+- Your MMA Custom text log will lose the ability to write to the custom log.
+To continue to write you custom data from both MMA and AMA each must have its own custom table. Your data queries in LA that process your data must join the two tables until the migration is complete at which point you can remove the join. 
+  
+## Migration
 You should follow the steps only if the following criteria are true:  
 - You created the original table using the Custom Log Wizard.
 - You're going to preserve the existing data in the table.
-- You're going to write new data using and [AMA custom text log DCR](data-collection-log-text.md) and possibly configure an [ingestion time transformation](azure-monitor-agent-transformation.md).
+- You do not need MMA agents to send data to the existing table
+- You're going to exclusively write new data using and [AMA custom text log DCR](data-collection-log-text.md) and possibly configure an [ingestion time transformation](azure-monitor-agent-transformation.md).
 
+## Procedure
 1. Configure your data collection rule (DCR) following procedures at [collect text logs with Azure Monitor Agent](data-collection-log-text.md) 
 2. Issue the following API call against your existing custom logs table to enable ingestion from Data Collection Rule and manage your table from the portal UI. This call is idempotent and future calls have no effect. Migration is one-way, you can't migrate the table back to MMA.