Configuration Reference

Configuration file

By default, Redistill loads redistill.toml from the current working directory. You can override this with the REDISTILL_CONFIG environment variable:

REDISTILL_CONFIG=/etc/redistill.toml ./redistill

Default configuration (simplified):

[server]
bind = "127.0.0.1"
port = 6379
num_shards = 256
batch_size = 16
buffer_size = 16384
buffer_pool_size = 1024
max_connections = 10000
connection_timeout = 300
connection_rate_limit = 0
health_check_port = 0

[security]
password = ""
tls_enabled = false
tls_cert_path = ""
tls_key_path = ""

[memory]
max_memory = 0
eviction_policy = "allkeys-lru"
eviction_sample_size = 5

[logging]
level = "info"
format = "text"

[performance]
tcp_nodelay = true
tcp_keepalive = 60

[persistence]
enabled = false
snapshot_path = "redistill.rdb"
snapshot_interval = 300
save_on_shutdown = true

Configuration sections

[server]

• bind – interface to bind (e.g. "127.0.0.1", "0.0.0.0").
• port – Redis TCP port (default: 6379).
• num_shards – number of internal shards for the in-memory store; powers of two recommended.
• batch_size – commands batched before flushing to the network.
• buffer_size – per-connection buffer size in bytes.
• buffer_pool_size – number of pre-allocated buffers.
• max_connections – maximum concurrent connections (0 = unlimited).
• connection_timeout – idle connection timeout in seconds (0 = no timeout).
• connection_rate_limit – maximum new connections per second (0 = unlimited).
• health_check_port – HTTP health endpoint port (0 = disabled).

[security]

• password – password required for AUTH (empty = no authentication).
• tls_enabled – enable TLS/SSL using Rustls.
• tls_cert_path, tls_key_path – certificate and key files in PEM format.

[memory]

• max_memory – maximum memory usage in bytes (0 = unlimited).
• eviction_policy – allkeys-lru, allkeys-random, allkeys-s3fifo, or noeviction.
• eviction_sample_size – number of keys sampled when choosing eviction candidates.

[logging]

• level – error, warn, info, debug, trace.
• format – text or json.

[performance]

• tcp_nodelay – disable Nagle's algorithm for lower latency.
• tcp_keepalive – TCP keepalive interval in seconds (0 = disabled).

[persistence]

• enabled – enable snapshot-based persistence (default: false).
• snapshot_path – path to snapshot file (e.g. "redistill.rdb").
• snapshot_interval – auto-save interval in seconds (0 = disabled).
• save_on_shutdown – save snapshot on graceful shutdown.

Environment variables

Environment variables override redistill.toml settings. Common ones include:

Example configurations

Production high-performance

[server]
bind = "0.0.0.0"
port = 6379
num_shards = 512
batch_size = 32
max_connections = 50000
connection_rate_limit = 5000
health_check_port = 8080

[security]
password = "your_secure_password"
tls_enabled = true
tls_cert_path = "/etc/letsencrypt/live/domain.com/fullchain.pem"
tls_key_path = "/etc/letsencrypt/live/domain.com/privkey.pem"

[memory]
max_memory = 8589934592  # 8GB
eviction_policy = "allkeys-lru"

[performance]
tcp_nodelay = true
tcp_keepalive = 120

[persistence]
enabled = true
snapshot_path = "/data/redistill.rdb"
snapshot_interval = 300
save_on_shutdown = true

Development

[server]
bind = "127.0.0.1"
port = 6379
num_shards = 64

[security]
password = ""  # no auth for local dev

[memory]
max_memory = 1073741824  # 1GB

[logging]
level = "debug"

Tuning highlights

• num_shards – increase for high concurrency (2048+), decrease to save memory.
• batch_size – smaller for low-latency interactive workloads, larger (matching pipeline depth) for throughput.
• max_memory – set to ~75–80% of host RAM after accounting for OS and other processes.
• eviction_policy – allkeys-lru for general caches, noeviction when you prefer errors over eviction.

Troubleshooting

• Port in use – adjust server.port or free the existing port.
• Invalid bind address – confirm you are using a valid IP/hostname.
• TLS failures – check tls_cert_path and tls_key_path and verify they are readable.
• High memory usage – ensure max_memory and an eviction policy are set; monitor via INFO.