Redis write

Writes one key to a Redis cache with an expiry: the whole input as JSON, or a text from an expression. Use it to fill a cache, for idempotency (write only if missing) and to share values with C# scripts that use StackExchange.Redis or IDistributedCache.

Pins

Pin	Kind	Types	Description
Input	input	any	The record to store (empty Value), and what the expressions read.
Written	continue	same as input	The unchanged input, after the value was stored.
Exists	no data	same as input	Condition 1 only: the unchanged input, when the key already existed and nothing was written.

Configuration

The configuration is shared with Redis read and Redis delete.

Field	Type	Default	Description
ConnectionString	string (max 2048)		Required. StackExchange.Redis configuration string, e.g. redis1:6379,ssl=true,password=...,defaultDatabase=0.
StorageMode	dropdown: 0 String, 1 DistributedCache	0	0: a plain Redis string (SET). 1: the IDistributedCache hash format (data, absexp, sldexp).
InstanceName	string (max 255)		Visible with StorageMode 1. Prefix in front of every key, the RedisCacheOptions.InstanceName of the scripts.
ConnectTimeoutMs	integer (min 1)	5000	Connect timeout in milliseconds.
SyncTimeoutMs	integer (min 1)	5000	Timeout of one operation in milliseconds.
CaCertificate	certificate name		CA that signed the server certificate (ssl=true, private CA). Empty: OS trust store.
ClientCertificate	certificate name		Client certificate with private key for mutual TLS.
Key	string (max 1024)		Required. The key, usually an expression: order:{data.OrderId}.
Value	text		Text to store, usually an expression such as {data.Token}. Empty: the whole input as JSON.
Ttl	integer (min 0)	3600	Absolute time to live in seconds. 0: no expiry.
SlidingTtl	integer (min 0)	0	Visible with StorageMode 1. Sliding expiration in seconds: the entry expires when not read for this long. 0: none.
Condition	dropdown: 0 Always, 1 Only if missing	0	Visible with StorageMode 0. 1: SET NX, writes only when the key doesn't exist; otherwise the record goes to Exists.

Behaviour

• Key and Value are evaluated for every record: {data.X} is the input, {meta.X} the metadata, {config.X} the flow configuration. An empty key fails that record. Ttl and SlidingTtl are fixed numbers (an expression setting =Package.Setting works, a per-record expression doesn't).
• Empty Value: the input is stored as JSON written by ViaJsonSerializer (default options, UTF-8), byte for byte what a script writes with ViaJsonSerializer.Serialize. A Value is stored as is (UTF-8 text).
• The connection is opened at flow start and shared by all Redis components on the Host with the same connection string, timeouts and certificates. A wrong connection string, a missing certificate, an unreachable server or Condition 1 with StorageMode 1 stops the flow at start.
• A timeout or lost connection fails that record (recoverable error); the next record is tried again.

Notes

• Keys without expiry (Ttl 0) stay until deleted and fill a large cache; choose it deliberately.
• Condition 1 gives claim-once and idempotency without a lock: the first record writes, the others go to Exists. IDistributedCache has no such call, so it isn't available in DistributedCache mode.
• To store part of the input as JSON, shape it with the data mapper first and leave Value empty.
• Keep the password in an expression setting: "ConnectionString": "=Secrets.RedisConnection".

Example

Process each order once, across Hosts:

{ "ConnectionString": "=Secrets.RedisConnection", "Key": "processed:{data.OrderId}", "Value": "1", "Ttl": 86400, "Condition": 1 }

Kafka consumer → Json deserializer → Redis write ─ Written → process the order; Exists → Log (duplicate)