System log shows errors and warnings which occur while using the tracker. You can either contact our support to solve the issues, or check our troubleshooting page for more info.
This tab shows the queue of all the postbacks received disregarding of them being processed and added to conversions or not. That means you'll be able to see incorrect subids there if a postback wasn't set up correctly.
This tab shows the postbacks which Keitaro sends to third-party services when you set up an S2S-postback. All queries can be found in this tab.
If this log is enabled you'll see how the filters worked and why each of your clicks was sent to this or another stream. We don't recommend constantly enabling this log, as the info requires a lot of space in your database.