Hi,

during evaluation of the Hashicorp Plugin I noticed the problem, that after a rotation of the encryption key in vault (set version 2 of the secret) and a restart of mariadbd I got an request loop (dos) from the hashicorp plugin against vault.

Reproduce by:

• Install mariadb-server & mariadb-plugin-hashicorp-key-management 10.9.1
• Install hashicorp vault, init and unseal vault
• create secret engine & set a secret key and enable audit_log for debugging purpose:

  vault secrets enable -path /mariadb -version=2 kv

  vault kv put /mariadb/1 data=$(openssl rand -hex 32)

  vault audit enable file file_path=/hashicorp/vault_audit.log

• enable encryption by adding the following block to mariadb section in /etc/mysql/mariadb.conf.d/50-server.cnf:

  [mariadb]

  plugin_load_add = hashicorp_key_management

  hashicorp-key-management-vault-url=http://127.0.0.1:8200/v1/mariadb

  hashicorp-key-management-token=xxxxxxxxxxxxxxxxx

  innodb_encrypt_tables = FORCE

  innodb_encrypt_log = ON

  innodb_encrypt_temporary_tables = ON

  encrypt_tmp_disk_tables = ON

  encrypt_tmp_files = ON

  encrypt_binlog = ON

  aria_encrypt_tables = ON

  innodb_encryption_threads = 4

  innodb_encryption_rotation_iops = 2000

  log_error=server.log

• set new key version

  vault kv put /mariadb/1 data=$(openssl rand -hex 32)

• service mariadb restart
• check /hashicorp/vault_audit.log mariadbd sends an endless loop of requests to vault
  Load of my 1vCPU Instance increases to 7 due to high cpu load of vault & mariadbd