Create a TDE-enabled cluster

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You can secure your data at rest and protect sensitive information by enabling transparent data encryption (TDE) in AlloyDB Omni. This document describes how to create a TDE-enabled cluster by providing required vault environment variables and the --tde-kek-url flag in the POSTGRES_INITDB_ARGS environment variable during database initialization.

Before you begin

  • Read Plan your AlloyDB Omni installation.
  • When you plan your AlloyDB Omni deployment with TDE enabled, be sure to account for additional CPU usage based on your anticipated workload and data volume. Encryption and decryption are compute-intensive operations.

Create the cluster

To create a TDE-enabled cluster, you must pass the necessary Key Management Service (KMS) configuration and authentication credentials during the initialization of the database. The only supported authentication type is jwt.

  1. Install AlloyDB Omni using RPM to prepare your environment and install the AlloyDB Omni RPM package.

  2. Initialize the database.

    HashiCorp Vault KMS

    Use this approach for production workloads.

    1. Run the following command to initialize the database with TDE enabled:

      sudo PGPASSWORD=POSTGRES_PASSWORD \
PGDATA=DATA_DIR \
VAULT_AUTH_TYPE=jwt \
VAULT_AUTH_MOUNT=JWT_AUTH_ENGINE_MOUNT \
VAULT_JWT_PATH=JWT_FILE_PATH \
VAULT_ROLE=VAULT_ROLE \
VAULT_CERT_PATH=VAULT_CERT_PATH \
POSTGRES_INITDB_ARGS="--tde-kek-url=KEK_URL" \
/usr/lib/postgresql/18/bin/alloydbomniproduct_major_version_numeric-setup initdb

      Replace the following:

      • POSTGRES_PASSWORD: the password for the database user.
      • DATA_DIR: the local directory to mount as the data volume for AlloyDB Omni—for example, /local/data.
      • JWT_AUTH_ENGINE_MOUNT: the path where the HashiCorp Vault authentication engine is mounted—for example, /auth/jwt.
      • JWT_FILE_PATH: the path where vault JWT is stored on your nodes—for example, tde-tls/jwt-token.
      • (Optional) VAULT_ROLE: the client role defined in your vault setup that lets HashiCorp Vault verify the JWT token authenticity.
      • VAULT_CERT_PATH: the path where the certificates for the vault connection are located on your nodes—for example, /tde-tls. If not set, the certificates in the default trust store are used.
      • KEK_URL: the fully qualified URL to the KEK in HashiCorp Vault. Use vault as the protocol to specify HashiCorp Vault as the KMS provider—for example, vault://127.0.0.1:8200/v1/secrets/data/alloydb_kek.

    2. To create an override file for alloydbomni18.service in /etc/systemd/system/alloydbomni18.service.d/override.conf, add the following to the override.conf file:

      [Service]
Environment="VAULT_AUTH_TYPE=VAULT_AUTH_TYPE"
Environment="VAULT_AUTH_MOUNT=JWT_AUTH_ENGINE_MOUNT"
Environment="VAULT_JWT_PATH=JWT_FILE_PATH"
Environment="VAULT_ROLE=VAULT_ROLE"
Environment="VAULT_CERT_PATH=VAULT_CERT_PATH"

      Replace the following:

      • VAULT_AUTH_TYPE: the type of authentication to use for the vault connection. Only jwt is supported.
      • JWT_AUTH_ENGINE_MOUNT: the path where the HashiCorp Vault authentication engine is mounted—for example, /auth/jwt.
      • JWT_FILE_PATH: the path where vault JWT is stored on your nodes—for example, tde-tls/jwt-token.
      • (Optional) VAULT_ROLE: the client role defined in your vault setup that lets HashiCorp Vault verify the JWT token authenticity.
      • VAULT_CERT_PATH: the path where the certificates for the vault connection are located on your nodes—for example, /tde-tls. If not set, the certificates in the default trust store are used.

    3. To apply the changes, reload the systemd daemon.

      sudo systemctl daemon-reload

    File-based KMS

    Use this approach for testing purposes only.

    To test TDE locally using a file-based key, you must first generate a 32 byte KEK on your machine.

    1. Create the directory, generate the key, and set the appropriate permissions.

      KEK_DIR=KEK_DIR
mkdir -p $KEK_DIR
sudo chown 999:999 $KEK_DIR
openssl rand -base64 32 | sudo tee $KEK_DIR/key
sudo chmod 0755 $KEK_DIR/key

    2. Initialize the database by passing the local file URI as your KEK URL.

      sudo PGPASSWORD=POSTGRES_PASSWORD \
PGDATA=DATA_DIR \
POSTGRES_INITDB_ARGS="--tde-kek-url=file:///$KEK_DIR/key" \
/usr/lib/postgresql/18/bin/alloydbomniproduct_major_version_numeric-setup initdb

      Replace the following:

      • POSTGRES_PASSWORD: the password for the database user.
      • DATA_DIR: the local directory to mount as the data volume for AlloyDB Omni—for example, /local/data.
      • KEK_DIR: the directory where the local file-based KEK is stored—for example, /tmp/alloydb/kms.

  3. After the database is initialized, follow the instructions in Install AlloyDB Omni using RPM to prepare the database, set up the host, and start the systemd service.

  4. To enable TDE for columnar engine cache data spilled to SSD storage, connect to your database instance and run the following query:

    ALTER SYSTEM SET google_columnar_engine.enable_tde_for_storage_cache = 'on';

  5. Restart your database server for the changes to take effect.

TDE metrics references

You can view all TDE metrics in AlloyDB Omni's monitoring agent. The following table describes each metric.

Name Description Label Unit Type
alloydb_omni_database_tde_data_blocks_decrypted_count_total Number of data blocks decrypted. Not applicable counter
alloydb_omni_database_tde_data_blocks_encrypted_count_total Number of data blocks encrypted. Not applicable counter
alloydb_omni_database_tde_data_decryption_time_us_total Total time spent in data block decryption. Not applicable microseconds counter
alloydb_omni_database_tde_data_encryption_time_us_total Total time spent in data block encryption. Not applicable microseconds counter
alloydb_omni_database_tde_enabled TDE enabled status. Not applicable gauge
alloydb_omni_database_tde_kek_info TDE KEK information.
  • kek_version: Version of the KEK
    in use for key wrapping.
  • kek_url: Fully qualified path
    to KEK in KMS
  • kek_creation_timestamp:
    Creation time of the KEK version in use.
 gauge
alloydb_omni_database_tde_temp_blocks_decrypted_count_total Number of temporary blocks decrypted. Not applicable counter
alloydb_omni_database_tde_temp_blocks_encrypted_count_total Number of temporary blocks encrypted. Not applicable counter
alloydb_omni_database_tde_temp_decryption_time_us_total Total time spent in temporary block decryption. Not applicable microseconds counter
alloydb_omni_database_tde_temp_encryption_time_us_total Total time spent in temporary block encryption. Not applicable microseconds counter
alloydb_omni_database_tde_wal_blocks_decrypted_count_total Number of WAL blocks decrypted. Not applicable counter
alloydb_omni_database_tde_wal_blocks_encrypted_count_total Number of WAL blocks encrypted. Not applicable counter
alloydb_omni_database_tde_wal_decryption_time_us_total Total time spent in WAL block decryption. Not applicable microseconds counter
alloydb_omni_database_tde_wal_encryption_time_us_total Total time spent in WAL block encryption. Not applicable microseconds counter
tde_chill_cache_blocks_encrypted Number of chill cache blocks encrypted. Not applicable counter
tde_chill_cache_blocks_decrypted Number of chill cache blocks decrypted. Not applicable counter
tde_chill_cache_blocks_total_encryption_time_us Total time spent in chill cache block encryption. Not applicable microseconds counter
tde_chill_cache_blocks_total_decryption_time_us Total time spent in chill cache block decryption. Not applicable microseconds counter
tde_ce_cache_ssd_blocks_encrypted Number of columnar cache blocks spilled to SSD storage that were encrypted. Not applicable counter
tde_ce_cache_ssd_blocks_decrypted Number of columnar cache blocks spilled to SSD storage that were decrypted. Not applicable counter
tde_ce_cache_ssd_blocks_total_encryption_time_us Total time spent encrypting columnar cache blocks spilled to SSD storage. Not applicable microseconds counter
tde_ce_cache_ssd_blocks_total_decryption_time_us Total time spent decrypting columnar cache blocks spilled to SSD storage. Not applicable microseconds counter