The geodatabases are on a 2-node RAC. For loads to both test and production (on different racks in different buildings) tnsnames.ora pointing to one node only. For the test geodatabase, when we point to the node with the setting SQLNET.SEND_TIMEOUT = 600, the load is successful. When we point to the other node, it fails after varying numbers of records.
Our problem is that the DBA is nervous about using the SQLNET.SEND_TIMEOUT = 600 setting on the production database, where it will affect other production databases for other client agencies. Any experience anyone has had with this would be helpful. Also if this problem can be solved some other way, or if a later version of the desktop software has a fix. We have had problems with ArcCatalog 10.5.1 too.
I will submit a service ticket also.
How large of a table are you loading? Also by loading, do you mean performing writes to the database itself via data loading, or simply drawing or querying the database to view data in ArcGIS Desktop? Does this appear to be data specific or only size specific? It appears that the solution you mentioned (SEND_TIMEOUT setting) is typically recommended: https://kb.informatica.com/solution/23/Pages/40/262530.aspx
Could you test lowering the 600 setting to something lower that would still allow the operation to complete that your DBA would be more satisfied with? Lastly, have you ruled out any network instability or intermittent connection drops from clients to the geodatabases involved with the testing? I hope this is helpful!