If you have a way to pull and format data from another system, the Apex Data Loader is a great, on-demand way to push data into Salesforce CRM. Without much effort, you can automate the process and create a hands-free data sync. The tricky part is that while the Data Loader creates excellent logs, there's no obvious way to alert a person when a data sync fails. Once a system is in place, failures are rare, but, in real life, stuff happens, and it's helpful if failsafes are in place.
A key problem is that the Apex Data Loader writes an error log whether there are errors or not. If the pass is 100% successful, the error log will have a header line and no rows.
If the error log was only written when errors occurred, we could just look for the error logs, and process the files whenever they crop up. But, in this case, we first need to look inside the log and count the lines before we can be sure there was a failure.
