Global.get fails while using contextStorage(redis)

General
1

While using redis contextStorage as default and use global.get() it results in an error as below.

"Error: Callback must be a function"

Using the below redis package.

GitHub - node-red/node-red-context-redis: A Node-RED Context store plugin backed by Redis

global.set() goes through and my redis-cli has stored the value too that I can query and check.

This doesn't happen with default being filesystem (and obviously memory)

I cannot make redis context as default. I would like both durability + Transactionality hence was trying redis context storage for this purpose.

contextStorage: {
        default: {
            module: require("node-red-context-redis"),
            config: {
               host: "127.0.0.1",
               port: 6379,
               db:0,
               password:"mypassword",

            }
        },
},

I can selectively use redis for storing explicitly without making it default

global.set("myglobalkey","myval","redis");
context.set("mycontextkey","myval2","redis");
..
global.get("mykey","redis");
context.get("mycontextkey","redis");

Has anyone faced this issue?

2

Assuming you are talking about accessing values in a function node, use the callback signature. This is necessary as the storage is remote and cannot be synchronous.

image
image501×169 6.16 KB

global.get("key", "redis", function(err, data) {
   if (err) {
      // didnt work
   } else {
      // worked - use the data!
      node.warn({data})
      node.send({payload: data})
   }
})
3

Check the documentation about asynchronous context storage: Writing Functions : Node-RED

If context storage does not implement synchronous reads and writes (that only works with nodered core memory and file storage), you get the value inside a passed callback to get function.

This error is telling you that you did not provide that callback function when calling get.