If your node is not synchronized, you may see logs similar to the following:
INFO [12-07|10:04:51.115] Imported new chain segment .... age=10d10h
The age=10d10h part shows that this node is still processing a block from 10 days ago.
If your node is well synchronized, you will still see logs starting with "Imported new chain segment", but there will be nothing like age=xxx in those lines.
Why is my node stuck after restarting from crash?
Sometimes, if your node exits unexpectedly, you may see logs like the following:
WARN [12-07|10:04:51.115] Head state missing, repairing
In most cases, you must wait a little longer for it to recover. If you are not running an archive node, the state in the memory is occasionally flushed to the disk. If the state in the memory is not flushed to the disk yet, an unexpected exit will cause the missing state. Don't worry. The node will try to replay some blocks and recover the state automatically.
Why cannot my node connect to any peers?
If you see logs like the following, your node is not connected to any other nodes (peers):
INFO [12-07|10:04:51.115] Looking for peers peercount=0 tried=20 static=0
The peercount=0 signals that your node is not connected to any other nodes. The underlying wire protocol is TCP based. You should check your network and see if it can connect to another network peer that listens on port 30303/TCP.