3754453 - SAP Signavio Process Intelligence - ServiceNow Table Preview Fails with PREVIEW_RESPONSE_SQL_ERROR and "Socket closed"

When attempting to preview a table from a ServiceNow source data connection in SAP Signavio Process Intelligence, the preview fails with the error key PREVIEW_RESPONSE_SQL_ERROR and the detail "Socket closed". The issue occurs consistently across different ServiceNow tables and regardless of whether a SQL filter is applied. Extracting the same table via a full extraction run succeeds without issue.

The error returned in the SAP Signavio Process Intelligence UI is:

Something went wrong
Socket closed

The error key reported in the backend is PREVIEW_RESPONSE_SQL_ERROR.

This behaviour is observed even when the ServiceNow instance is accessible from a browser and direct API calls to the instance return results immediately.

When SAP Signavio Process Intelligence executes a table preview for a ServiceNow connection, the ServiceNow connector fetches column metadata for all available tables at connect time by paging through the ServiceNow sys_dictionary system table. On large ServiceNow instances this operation can take several minutes to complete. The default connection timeout of 60 seconds is exceeded before this operation completes, causing the REVIEW_RESPONSE_SQL_ERROR and "Socket closed" error.

The delay is not related to the size of the table being previewed, the number of columns selected, or the presence of a SQL filter. 

Add the following to the Extra Connection Arguments field of the affected ServiceNow connection:

  GetColumnsMetadata=OnUse

This instructs the connector to defer metadata retrieval until the first time each table is actually queried, avoiding the full sys_dictionary scan at connect time entirely. 

Steps:

1. Edit the connection settings.
2. In the Extra Connection Arguments field, add: GetColumnsMetadata=OnUse
3. Save the connection.
4. Retry the table preview.

Note: If the preview continues to fail after applying the above, consider also setting Timeout=600 (and possibly increasing it further if required) to increase the general connection timeout beyond the default 60 seconds. This may be relevant if the ServiceNow instance is slow to respond for reasons unrelated to metadata retrieval.

soe, SAP Signavio Process Intelligence, ServiceNow, table preview, preview timeout, Socket closed, PREVIEW_RESPONSE_SQL_ERROR, source data, connection timeout, Extra Connection Arguments, extraction, preview fails, ServiceNow connector, GetColumnsMetadata, sys_dictionary, metadata , KBA , BPI-SIG-PI-DM , Data model / ETL for SAP Signavio Process Intelligence , Problem