Recently noticed that my core Node is using 100% cpu and whilst trying to fire up a eclair lightning node i noticed that the log said "Blockchain transactions are still in the process of being indexed". how ever my node has been running for months. any ideas?
In case your node is pruned, running a lightning node is not supported by almost all the current libraries. You need a full node.
But yes, in case that isn't the problem please share the last lines of your .bitcoin/debug.log file.