Writeback troubleshooting

Use this page when Writeback shows a message you do not understand. Find the message under the area you were working in, then follow what to do.

Tip

For a run that failed or was skipped, open the table's Settings tab and read its Sync Log. The Error and Note columns give the reason. See Synchronize a table and read the Sync Log.

Connecting a destination

Messages from the destination forms. For the forms and their settings, see Add and manage destinations.

You see	What it means and what to do
Connection test successful	The test passed. Click Add (or Save) to save the destination.
Connection failed	The test failed. Hover over it to read Error Details, the message the destination returned. Check the host, port, username, password, SSL setting and network access, then test again.
Failed to test connection (in Error Details)	The test failed and the destination gave no reason. Check the same settings, then test again.
Name is required or Name must be at least 3 characters	Enter a name of at least 3 characters.
Code is required or Code must be at least 2 characters	Enter a code of at least 2 characters.
Code must contain only letters and numbers	The code has a space or a symbol. Replace it with letters and numbers only.
Host is required, Port is required, Username is required or Password is required	Fill in the field.
This name is already in use or This code is already in use	Another destination uses this name or code. Choose another.
Failed to create connection, Failed to edit connection or Failed to duplicate connection	Saving failed and the destination gave no reason. Check the fields and try again. When you edit a destination, the message appears on the form.
Error toast with a message from the server	The save was refused. The text under Error is the reason the server returned; fix what it names and save again.
Connection added successfully, Connection updated successfully or Connection duplicated successfully	The destination is saved. Nothing to do.
Unsaved Changes: You have unsaved changes. Are you sure you want to close? All changes will be lost.	You are leaving a destination form you changed. Click Confirm to discard the changes, or Cancel to keep editing.
Do you wish to Revert all changes? (editing) or Do you wish to Reset form? (adding or duplicating)	Revert discards the form's unsaved changes and restores the last saved state; the dialog warns this cannot be undone. Confirm only if you want that, otherwise cancel.
No data available: This data source type does not have a connection form available.	The type you picked has no form. Close it and choose another type.
Data source not found	The destination could not be opened and the server gave no reason. Click Refresh in the toolbar, then try again.

RabbitMQ destinations

For the destination form itself, see Publish to RabbitMQ.

You see	What it means and what to do
Exchange is required - messages are published into it	Enter the Exchange name. Messages are published into that exchange.
Message schemas: invalid JSON	The text in Message Schemas (optional) is not valid JSON. Fix the JSON.
Message schemas must be a non-empty JSON array of table entries	The field holds something other than a list of entries. Wrap the entries in square brackets, or clear the field.
Message schema entry <n> must be an object	Entry <n> is not an object. Fix that entry.
Message schema entry <n>: "name" is required and must be a non-empty string	Give the entry a table name.
Message schema entry <n> ("<name>"): "columns" must be an array (omit it to auto-detect from live messages)	Make columns a list, or leave it out to detect the columns from live messages.
Message schema entry <n> ("<name>"): column <n> must be an object	Fix that column in the entry.
Message schema entry <n> ("<name>"): column <n> needs a non-empty "name"	Give the column a name.
Message schema entry <n> ("<name>"): column "<name>" needs a "type"	Give the column a type.
Connection test passed	The broker check in the Test connection card succeeded. Nothing to do; continue with Add.
Connection test failed	The broker check failed; the reason from the broker appears under the title. Read it; check Host, Port, Username and Password (and that the management API port answers when discovery is used), then test again.

Importing tables

Messages from the picker beside the tree. For the picker itself, see Import destination tables.

You see	What it means and what to do
Failed to load source menu	The destination's tables could not be listed. Read the reason, check the connection and click Retry.
No tables available: There are no tables to import from this source.	The destination has no tables. Create the table in the destination, then open the source menu again.
Import in progress: Tables are being imported. Please wait until processing completes.	An import is still running. Wait for it to finish.
Please wait for import to complete	The picker cannot be closed while an import runs. Wait for the import to finish, then close the picker.
Importing...	The import is running; the picker is locked and the Import button shows a spinner. Wait; the picker unlocks when the import finishes.
Import <n> databases, <n> schemas and <n> tables	The tooltip on Import counts the current selection; parts with zero are left out, for example Import 2 schemas and 5 tables. While an import runs it reads Import in progress, and Select items to import when nothing is ticked. Hover over Import to read the breakdown.
All tables imported: Every available table has already been imported.	Every table is already in Writeback. There is nothing to import.
No results found for "<search text>"	The search in the picker matched nothing. Check the spelling, or clear the search and expand the branches by hand.
Import completed successfully.	The tables are imported. Configure them. See Configure a Writeback table.
The schema contains too many tables for processing, maximum number per import is 500, consider splitting	One import can take at most 500 new tables from a schema. Tick fewer tables and import the rest later.
An unexpected error occurred	The import failed and no reason came back. Try again. If it fails again, check that you have Add/Modify Lake Objects.

The destination tree

Statuses and toolbar messages of the tree. For the badges and the toolbar, see The Writeback screen.

You see	What it means and what to do
No Data Sources Found	You have no destinations yet. Click Add destination to add one.
No connections in this group	A dashboard card has no destinations to list. Use the card's Add data source to add a destination of that type.
No items to display	The tree has nothing to show. Add a destination with Add destination, then import its tables.
No items match the current filters	A tree filter hides every row. Change or clear the filter; the Filter button's badge shows how many filters are active.
No results for "<query>"	The tree search found nothing. Check the spelling, or search for a shorter part of the name; the search matches anywhere in the name.
Showing first 50 results	The search hit its 50-result cap. Type more of the name to narrow the list.
Failed (badge on a destination; the tooltip reads Click to open error logs)	The last sync of the destination failed. In the tree, click the Failed badge to open Error Details - <name>. Read or copy the error, fix the cause, then run Sync Schema again.
Unknown (status badge)	The screen does not recognise the destination's status. Click Refresh in the toolbar to reload the tree; if it stays, ask your administrator.
Stopped (status badge)	You stopped a sync of this destination yourself; it is not an error. Nothing to do.
Error Details - <name> with Copy, Copied and Close	The destination's error log. Click Copy to copy the text; the button shows Copied for about 2 seconds. Click Close when you are done.
Synchronization started	Sync Schema or Synchronize has started. The destination shows Processing until it finishes; wait for the status, or check the Sync Log.
Failed to synchronize	Sync Schema failed and the server gave no reason. Try again, and check the destination connection.
Data refreshed successfully or Failed to refresh data	The Refresh on a tree row worked, or it failed. On failure, try again.
Items deleted successfully or Failed to delete items	On failure, the items return to the tree. Read the message for the reason, then try again.

Deleting

You see	What it means and what to do
Delete Selected Items? with This action cannot be undone.	You are deleting the selected items from the toolbar. Check the summary and confirm only if they should go.
This action will permanently remove this table. This operation cannot be undone.	You chose Delete from the right-click menu. The last noun matches what you delete: data source (a destination), database, schema or table. Confirm only if nothing needs the item.
Could not load every dependant, so the list may be incomplete.	The list of items that depend on this one may be short. Check Lineage before you delete.
Dependants could not be determined because the check failed. Deleting may be unsafe.	The dependency check failed. Do not delete yet. Check Lineage, then try again.
Cannot remove table "<name>": it is used as the source for a writeback. Remove it from the writeback first	A Lake or Warehouse table feeds a Writeback table, so it cannot be removed. Change the source of that Writeback table, or delete the Writeback table, then remove the table.

Configuring a table

The editor's saves and loads. For its tabs and steps, see Configure a Writeback table.

You see	What it means and what to do
Query cannot be empty	You clicked Validate with an empty query. Write a query, then validate it.
Query validation failed	The query failed without a readable reason. Check the query in the Editor, then validate again.
The database's error text, shown above the editor	The query has an error. Fix it and click Validate again.
Validation Error: Please complete and save the General configuration before continuing	Click Apply on General before you go on to Columns.
Validation Error: Please complete all required fields and validate your query before continuing	Choose a Workflow, pick a table or, for a query, click Validate after your last change.
Validation Error: Please fix column mapping errors before continuing	Fix the red entries on Columns, then continue; a new table also needs at least one column mapped or skipped.
Validation Error: Please complete all required fields before navigating or Please complete all required fields before finishing	Complete the unsaved changes, or revert them, then click Previous or Finish again.
Unsaved Changes: You have unsaved changes. How would you like to proceed?	Click Save & Continue to save and move on, or Cancel to stay. Discard & Continue appears only for a table that already exists.
You have unsaved changes. Refreshing will discard them and reload this popup from the server. Continue?	You clicked Refresh in the header with unsaved changes. Click Refresh again to discard the changes and reload from the server, or Cancel to stay and save them first.
Write-back configuration saved successfully	General is applied. Continue to Columns.
Failed to save write-back	Saving General failed and the server gave no reason. Try again.
Failed to save configuration	Saving the step failed and no other message came back. Try again.
Selected table not found in available options	The source table picked on General is no longer in the offered list when the save is built. Reload the editor, pick the table again and save.
Please select both table type and name before saving. or Please enter a SQL query before saving.	General is not ready to be saved: in table mode, choose both the table type and the table name; in query mode, write the query and click Validate. Then save again.
Write back already exists for table "<name>"	The destination table already has a configuration. Each destination table has only one, so this save was refused. Find that table in the tree and edit it there.
Preview Error	The preview query failed. Read the reason, fix the source, then click Retry.
Failed to load table data	The table preview or editor could not load. Click Retry (the button reads Retrying… while it works).
Publish window updated or Failed to update publish window	The Publish Window on a RabbitMQ table changed, or the change failed. On failure, try again.
No dependencies: This write-back has no upstream tables registered as dependencies.	The table has no upstream tables registered as dependencies to show. Check that the source is chosen and saved on General; when the table reads nothing upstream, this is expected.

Mapping columns

For the step itself, see Map columns.

You see	What it means and what to do
Please finish column mapping to enable this table	The table is not deployed. Open Columns, map at least one column, then click Apply.
Please validate your query in the General tab first	You are using a SQL query and it is not validated. Open General, click Validate, then return to Columns.
No table selected for column mapping	No source is chosen. Choose the source on General.
Failed to load column mapping data.	The mapping could not load. Click Retry.
No target columns available to save mappings	The table has no columns to map. Click Sync Schema on the destination, then reopen the table.
Please select data type or Invalid data type	A Data Type is empty or not recognised. Pick a type from the list.
No matching data type	The suggestion list found no type for the text typed so far. Finish typing the full type, or pick one from the list; the value is checked each time it changes.
No domains found matching "{searchQuery}"	The search in the domain list matched nothing. Clear the box, or type a word from the meaning you want, such as date, text or email.
Disabled due to foreign key constraint or Disabled because it's an audit row	The domain cannot be changed on this column: a foreign key constraint uses it, or it is an audit row. Nothing to fix; the row shows a Lock icon instead of the picker.
Column mappings saved successfully	The mapping is saved and the table is deployed. Run it or schedule it.

Synchronizing and the Sync Log

For running a table and reading the log, see Synchronize a table and read the Sync Log.

You see	What it means and what to do
Failed to synchronize table	The run did not start and the server gave no reason. Try again.
Failed to synchronize. Please try again.	The Synchronize dialog could not start the run. Try again.
Unable to synchronize, the table is not deployed	The table's column mapping is not saved. Map a column on Columns and click Apply.
The synchronization of this table is currently running.	Another run is active. Wait for it to finish. The Sync Log shows Syncing while it runs.
The workflow containing this table is currently running. Please wait for the workflow to complete before triggering synchronization.	The workflow that holds this table is running. Wait for it to finish.
Workflow for this table is on schedule and next run is in the next 1 hour period, Because of Potential Risk of Collision, Either Workflow or This table synchronization should be disabled	The workflow starts within the hour, so a manual run is refused to avoid a collision. Wait for the scheduled run, or turn the schedule off on the workflows page.
Tables load on the native executor - add the table to a job first, then synchronize it or run the job.	The table has no workflow. Pick a Workflow on General and click Apply.
Skip Reason: Synchronize Option Is Disabled, Skip Reason: Table Is Not Deployed or Skip Reason: Node Already Run	The run skipped the table. Several reasons can appear together, separated by semicolons, in the Note column of the Sync Log. For the first two, map at least one column on Columns and click Apply. For Node Already Run, start a new run. See Run, schedule and monitor Writeback.
No synchronization logs found	The table has never run. Click Synchronize to run it.

Workflows

For the Workflows view and table transfer, see Run, schedule and monitor Writeback and Transfer tables between workflows.

You see	What it means and what to do
No destinations ready: Add tables from the writeback menu first. Only destinations with at least one table appear here.	No destination has an imported table yet. Import tables first.
No destination selected: Choose a destination above to see its workflows.	The Workflows list has no destination chosen. Pick one under Destination; one is selected for you when the view opens.
No workflows yet	The destination has no workflows you can see. Click Add Workflow.
Select a destination first or Create workflow for this destination (the Add Workflow tooltip)	Add Workflow needs a destination to attach the new workflow to. Select a destination under Destination, then click Add Workflow.
Cannot add workflow: No workflow container exists for the selected destination.	The destination has no workflow group. Refresh the page. If the message stays, ask your administrator.
Can't run yet: None of this workflow's tables have finished column mapping, so it has nothing to push. Map at least one table, then run it.	The workflow has no table with a saved column mapping, so there is nothing to push. Map at least one table on Columns and click Apply, then run the workflow; Show destination opens the destination.
Workflow enabled successfully or Workflow disabled successfully	The schedule toggle on a workflow card was saved. Nothing to do; the card updates its frequency chip.
No fully mapped tables in this workflow.	The workflow has no table with a saved column mapping, so there is nothing to move. Map a table's columns on Columns and click Apply, then transfer again. The same text appears on the destination side when the target workflow is empty.
No tables match your search.	The transfer list's search found no table. Clear the search box.
Tables from different data sources cannot be assigned to the same metadata workflow	The move tried to combine tables from more than one destination. Retry with tables of a single destination.
Some tables are not compatible with Snapshot metadata type or Some tables are not compatible with Standard metadata type	A table's sync type does not fit the target workflow's type. Move the tables to a workflow whose type fits their sync types.
Select a destination or Select a source workflow	The transfer view needs a choice first. Pick a destination and a source workflow.
No other workflows with the same type on this destination.	There is no workflow to transfer to. Create another workflow of the same type on the destination, then transfer again.
You do not have permission to modify any destination workflow here.	You need Modify WriteBack Workflows to transfer tables into these workflows. Ask your administrator, and see Writeback permissions.
Transferred <n> table(s). or Transfer failed	The transfer finished, or it failed. On failure, try again.

Questions, answered

Why are rows missing in my destination after a run?

Open the table's Settings tab and read the latest row in the Sync Log. Processed Rows shows how many rows the run wrote, and Error shows why a run failed. See Synchronize a table and read the Sync Log.

Why does a run fail because a column cannot be empty?

A target column with no mapping, or one you skipped on Columns, receives an empty value (NULL). Map the column, or allow empty values in the destination. See Map columns.

Why does a run fail with a type conversion error?

The values in your source do not fit the Data Type of the target column. Check the type on Columns against the values in your source, then correct the type or the source. See Data types for columns and Map columns.

Why can't I remove a Lake or Warehouse table?

The table feeds a Writeback table. Change the source of that Writeback table on General, or delete the Writeback table, then remove the table. See Configure a Writeback table.

Why is my table still Unmapped after I mapped columns?

A table becomes Mapped once you save its column mapping. Choosing columns is not enough: click Apply on Columns. If the table still shows as Unmapped, click Refresh in the toolbar. See Map columns.

My import failed with "An unexpected error occurred". What should I check?

The import failed and no reason came back. Try it again. If it fails again, check that you have Add/Modify Lake Objects and that the destination connection still works, then retry from the picker. See Import destination tables.

Why did my table fail to open with "Failed to load table data"?

The table's data could not be loaded. Click Retry. If it keeps failing, check the destination connection, refresh the tree, then open the table again. See Configure a Writeback table.