Redis Writer

Introduction

redis_writer is used to write data to Redis-like databases.

Configuration

[redis_writer]
cluster = false
address = "127.0.0.1:6379" # when cluster is true, address is one of the cluster node
username = ""              # keep empty if not using ACL
password = ""              # keep empty if no authentication is required
tls = false

• cluster: Whether it's a cluster or not.
• address: Connection address. When the destination is a cluster, address can be any node in the cluster.
• Authentication:
  • When using the ACL account system, configure both username and password
  • When using the traditional account system, only configure password
  • When no authentication is required, leave both username and password empty
• tls: Whether to enable TLS/SSL. No need to configure certificates as RedisShake doesn't verify server certificates.

Important notes:

1. When the destination is a cluster, ensure that the commands from the source satisfy the requirement that keys' hash values belong to the same slot.
2. It's recommended to ensure that the destination version is greater than or equal to the source version, otherwise unsupported commands may occur. If a lower version is necessary, you can set target_redis_proto_max_bulk_len to 0 to avoid using the restore command for data recovery.

Duplicate Key Handling

When a key already exists in the target Redis, you can control the behavior using the rdb_restore_command_behavior configuration.

Configuration

[advanced]
rdb_restore_command_behavior = "panic"  # panic, rewrite, or skip

Options

Value	Description
panic	Stop when encountering duplicate keys (default)
rewrite	Overwrite the key in the target
skip	Skip duplicate keys

Applicability

Reader	Phase	Uses RESTORE	Config Applies
rdb_reader	RDB	✅ Yes	✅ Yes
sync_reader	RDB phase	✅ Yes	✅ Yes
sync_reader	AOF phase	❌ No (forwards commands directly)	❌ No
scan_reader	Full/KSN	✅ Yes	✅ Yes

Limitation

When data size exceeds target_redis_proto_max_bulk_len, individual commands (SET, HSET, etc.) are used instead of RESTORE, and this configuration may not be respected.