Earlier this week, we released Stellar Core v15.3.0. Download it and read the full release notes here:
This release includes some stability and performance improvements that, among other things, should help reduce the impact of network traffic spikes caused by arbitrage-seeking bots. For more info on those spikes, see this FAQ.
If you run Stellar Core, we urge you to upgrade to this version as soon as possible. Doing so is good for your node and for the network as a whole. If you have any questions, please let me know.