So I'm pool mining RandomX using XMRig, and I often see that along with the increasing "accepted" shares, the "expired" shares are also increasing. What does that mean? Am I running the miner correctly? The config.json file I'm using is generated using the XMRig wizard.
Those messages are coming from the pool.
An accepted share is just that; you have worked on a job the pool sent you and submitted the result, which has been accepted. You will be rewarded for it.
An expired share is when you took too long on the job and you will not be rewarded for it.
If you're getting many expired shares, it's typically because the difficulty level of the jobs you are getting from the pool is too high for your hardware. You ideally want jobs that will take no longer than 2 minutes to complete.
Pools usually have different ports for different starting difficulty targets, so ensure you are connecting to the most appropriate pool port for your hardware.
In almost all cases, regardless of the pool port used (thus your starting difficulty target), the pool will automatically adjust the difficulty of the jobs it sends you based on your prior submitted shares. Thus even if you start with a few expired shares, after a few minutes of mining, the pool should start sending you more appropriate difficulty targets.