We are announcing v4.0.3-hotfix. This release contains the necessary optimization to prevent the beacon node from high resource usage during turbulent times (as seen on May 11th and May 12th).
It is highly recommended to upgrade to this release if your node is under high resource usage.
When we receive an attestation for an old target, a node needs to regenerate the beacon state to validate the attestation. Performing several of these replays at the same time is what stresses the nodes' CPUs and bloats memory usage. A node has a cache of seen attestation targets designed to address this situation. With the increase in validator sizes and the number of this untimely attestation, this cache quickly filled and forced us to replay several times in the same state. This release contains a heuristic to filter out unviable checkpoint attestations, a node will ignore attestations if the target of the attestation is known to be old and not have been a checkpoint in any chain known to our node.
If you are running the prysm script:
For using prysm.sh: USE_PRYSM_VERSION=v4.0.3-hotfix ./prysm.sh beacon-chain
For using prysm.bat: set USE_PRYSM_VERSION=v4.0.3-hotfix prysm.bat beacon-chain
We'll have a formal point release 4.0.4 earlier next week that contains more changes from 4.0.3. We are currently testing the changes over the weekend.