Symptom:
The Elasticsearch run log records a large number of Invalid signature exceptions.
Cause analysis:
In security mode, a random number is used as the seed for signature verification. The random number exists on the ZooKeeper. However, when the instance is restarted or the cluster load is high, the random numbers obtained in some instances may be different from those in other instances, a different random number is used for verification. As a result, the signature is invalid.
Solution:
Workaround: Restart the ES service to avoid this problem.
Install the 303 patch.
