The referential integrity feature in Philter ensures that filtered values are replaced consistently across documents or contexts. When Philter is deployed in a cluster and is using referential integrity across contexts, a Valkey cache is required. The cache stores the replacement values so that all instances of Philter have access to the same replacement values for the same original values.
The Valkey cache will contain PHI. It is important to prepare your Valkey cache such that it can contain PHI.
Configuring the Valkey cache
To enable Philter to use the Valkey cache, set the following environment variables for Philter:
| Environment Variable | Description | Default Value |
|---|---|---|
CACHE_HOSTNAME | The hostname or IP address of the Valkey cache. | localhost |
CACHE_PASSWORD | The Valkey password. | (empty) |
CACHE_SSL | Whether to use SSL for communication with the Valkey cache. | false |
Replace localhost with the IP address or hostname of your Valkey cache.
If you are using Valkey on AWS ElastiCache, see ElastiCache for Valkey In-Transit Encryption (TLS) for information on using in-transit encryption.
Restart Philter
After starting (or restarting) Philter, it will use the Valkey cache for referential integrity across contexts.
Philter is part of Philterd’s open source PII redaction software toolkit .