Cluster Encrypted Inter-Node Communication
All the communication between the cluster nodes are end-to-end encrypted using OpenSSL.
Any valid TLS/SSL certificate issued by a certificate authority or a self-signed certificate will be accepted. For self-signed certificates, the verification level must be set to '0'. Client certificates are not validated in this case. Nevertheless, the communication is still encrypted.
The following table provides an overview of Adabas nucleus parameters related to cluster inter-node encryption with OpenSSL:

Parameter | Description
CLUSTER_CLIENT_CADIR | Points to a directory containing CA certificates in PEM format for client.
CLUSTER_CLIENT_CAFILE | CA certificate file or certificate chain file of client.
CLUSTER_CLIENT_CERTFILE | Fully qualified path name to certificate file of client.
CLUSTER_CLIENT_KEYFILE | Fully qualified path name to private key file of client.
CLUSTER_CLIENT_VERIFY | Verification level of client certificates: 0 = no verification 1-10 = maximum depth for certificate chain verification that shall be allowed
CLUSTER_CLIENT_PASSWD | Passphrase/password or path name to the file that contains the passphrase/password for client file. If using a file path, the pass phrase/password is encrypted on the first access and written back to the file. The file must have the write access permission. After encryption, change the file access permission to read-only. Password rules: Leading or trailing white spaces (like tabs and spaces) are ignored when reading passphrase/password from the file.
CLUSTER_SERVER_CADIR | Points to a directory containing CA certificates in PEM format for server.
CLUSTER_SERVER_CAFILE | CA certificate file or certificate chain file of server.
CLUSTER_SERVER_CERTFILE | Fully qualified path name to the certificate file of server.
CLUSTER_SERVER_KEYFILE | Fully qualified path name to the private key file of server.
CLUSTER_SERVER_VERIFY | Verification level of certificates: 0 = no verification 1-10 = maximum depth for the certificate chain verification that shall be allowed
CLUSTER_SERVER_PASSWD | Passphrase/password or path name to the file that contains the passphrase/password. If using a file path, the passphrase/password is encrypted on the first access and written back to the file. The file must have the write access permission. After encryption, change the file access permission to read-only. Password rules: Leading or trailing white spaces (like tabs and spaces) are ignored when reading passphrase/password from the file.
CLUSTER_TLS_ENABLED | Enable the TLS encryption for the node communication.