# 100% cpu when touching ui or a specific flow reloads

**URL:** <https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788>\
**Category:** General\
**Created:** [8 March 2020 12:24 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788 "2020-03-08T12:24:10Z")\
**Posts on this page:** 13\
**Page:** 1

<div class="post-metadata">

**Author:** ![billiaz](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/billiaz/32/17921_2.png) [@billiaz](https://discourse.nodered.org/u/billiaz)\
**Post date:** [8 March 2020 12:24 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788/1 "2020-03-08T12:24:10Z")

</div>

I've created a flow to control my thermostat and also to reset it after some time.  
While testing I set an inject to push timestamp every 5 seconds and if the last change on the thermostat +10 seconds is reached to reset. (this is not fully finished but yet)

The issue is, after some point of running it began eating memory and CPU! and I cannot understand why.  
The Flow is:

```auto
[
    {
        "id": "4398d66c.162748",
        "type": "mqtt in",
        "z": "ebd56e5.ec86b9",
        "name": "TRV CurrentTemp",
        "topic": "zwave2mqtt/HallwayFirst/TRV/49/1/1",
        "qos": "2",
        "datatype": "json",
        "broker": "90876955.0f6418",
        "x": 130,
        "y": 80,
        "wires": [
            [
                "1156e4a.3707d1b"
            ]
        ]
    },
    {
        "id": "6611a45c.a42f9c",
        "type": "ui_heater_controller",
        "z": "ebd56e5.ec86b9",
        "name": "heater",
        "group": "fbed6f0b.6a621",
        "unit": "C",
        "order": 1,
        "width": 0,
        "height": 0,
        "topic": "",
        "title": "",
        "logLengthType": "days",
        "logLength": "0",
        "sliderMinValue": 12,
        "sliderMaxValue": 28,
        "sliderStep": 0.5,
        "thresholdRising": 0.5,
        "thresholdFalling": 0.5,
        "calendar": "{\n \"Monday\": {\n \"00:00\": 19,\n \"06:20\": 22,\n \"08:00\": 19,\n \"16:40\": 22,\n \"23:59\": 19\n },\n \"Tuesday\": {\n \"00:00\": 19,\n \"06:20\": 22,\n \"08:00\": 19,\n \"16:40\": 22,\n \"23:59\": 19\n },\n \"Wednesday\": {\n \"00:00\": 19,\n \"06:20\": 22,\n \"08:00\": 19,\n \"16:40\": 22,\n \"23:59\": 19\n },\n \"Thursday\": {\n \"00:00\": 19,\n \"06:20\": 22,\n \"08:00\": 19,\n \"16:40\": 22,\n \"23:59\": 19\n },\n \"Friday\": {\n \"00:00\": 19,\n \"06:20\": 23,\n \"08:00\": 19,\n \"16:40\": 22,\n \"23:59\": 19\n },\n \"Saturday\": {\n \"00:00\": 19,\n \"08:00\": 20,\n \"20:00\": 22,\n \"23:59\": 19\n },\n \"Sunday\": {\n \"00:00\": 19,\n \"08:00\": 20,\n \"20:00\": 22,\n \"23:59\": 19\n }\n}",
        "x": 490,
        "y": 80,
        "wires": [
            [
                "a8e2dfa0.23693",
                "cfed7818.3ce6a8"
            ]
        ]
    },
    {
        "id": "1156e4a.3707d1b",
        "type": "change",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "rules": [
            {
                "t": "set",
                "p": "topic",
                "pt": "msg",
                "to": "currentTemp",
                "tot": "str"
            },
            {
                "t": "set",
                "p": "payload",
                "pt": "msg",
                "to": "payload.value",
                "tot": "msg"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 320,
        "y": 80,
        "wires": [
            [
                "6611a45c.a42f9c"
            ]
        ]
    },
    {
        "id": "a8e2dfa0.23693",
        "type": "switch",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "property": "payload.targetValue",
        "propertyType": "msg",
        "rules": [
            {
                "t": "neq",
                "v": "currentSetTemp",
                "vt": "flow"
            }
        ],
        "checkall": "true",
        "repair": false,
        "outputs": 1,
        "x": 690,
        "y": 160,
        "wires": [
            [
                "4043672b.9b5ef8"
            ]
        ]
    },
    {
        "id": "61949791.655088",
        "type": "change",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "rules": [
            {
                "t": "set",
                "p": "currentSetTemp",
                "pt": "flow",
                "to": "payload.value",
                "tot": "msg"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 490,
        "y": 440,
        "wires": [
            []
        ]
    },
    {
        "id": "26e241e0.01f89e",
        "type": "mqtt in",
        "z": "ebd56e5.ec86b9",
        "name": "TRV SetTemp",
        "topic": "zwave2mqtt/HallwayFirst/TRV/67/1/1",
        "qos": "1",
        "datatype": "json",
        "broker": "90876955.0f6418",
        "x": 230,
        "y": 440,
        "wires": [
            [
                "61949791.655088"
            ]
        ]
    },
    {
        "id": "4043672b.9b5ef8",
        "type": "change",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "rules": [
            {
                "t": "set",
                "p": "payload",
                "pt": "msg",
                "to": "payload.targetValue",
                "tot": "msg"
            },
            {
                "t": "set",
                "p": "#:(disk)::changeTimestamp",
                "pt": "flow",
                "to": "",
                "tot": "date"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 860,
        "y": 160,
        "wires": [
            []
        ]
    },
    {
        "id": "78177e54.cd333",
        "type": "inject",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "repeat": "5",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "x": 110,
        "y": 280,
        "wires": [
            [
                "687a69.d60d8598",
                "42b35a0.9de0ea8"
            ]
        ]
    },
    {
        "id": "cda34824.2d2678",
        "type": "switch",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "property": "($flowContext(\"changeTimestamp\", \"disk\") + 10000) < payload",
        "propertyType": "jsonata",
        "rules": [
            {
                "t": "true"
            }
        ],
        "checkall": "true",
        "repair": false,
        "outputs": 1,
        "x": 410,
        "y": 280,
        "wires": [
            []
        ]
    },
    {
        "id": "42b35a0.9de0ea8",
        "type": "debug",
        "z": "ebd56e5.ec86b9",
        "name": "Custom state",
        "active": true,
        "tosidebar": false,
        "console": false,
        "tostatus": true,
        "complete": "$flowContext(\"isUserCustom\", \"disk\")",
        "targetType": "jsonata",
        "x": 360,
        "y": 360,
        "wires": []
    },
    {
        "id": "cfed7818.3ce6a8",
        "type": "change",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "rules": [
            {
                "t": "set",
                "p": "#:(disk)::isUserCustom",
                "pt": "flow",
                "to": "payload.isUserCustom",
                "tot": "msg"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 760,
        "y": 80,
        "wires": [
            []
        ]
    },
    {
        "id": "687a69.d60d8598",
        "type": "switch",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "property": "#:(disk)::isUserCustom",
        "propertyType": "flow",
        "rules": [
            {
                "t": "true"
            }
        ],
        "checkall": "true",
        "repair": false,
        "outputs": 1,
        "x": 270,
        "y": 280,
        "wires": [
            [
                "cda34824.2d2678"
            ]
        ]
    },
    {
        "id": "90876955.0f6418",
        "type": "mqtt-broker",
        "z": "",
        "name": "Main MQTT",
        "broker": "mqtt",
        "port": "1883",
        "clientid": "",
        "usetls": false,
        "compatmode": false,
        "keepalive": "60",
        "cleansession": true,
        "birthTopic": "",
        "birthQos": "0",
        "birthPayload": "",
        "closeTopic": "",
        "closeQos": "0",
        "closePayload": "",
        "willTopic": "",
        "willQos": "0",
        "willPayload": ""
    },
    {
        "id": "fbed6f0b.6a621",
        "type": "ui_group",
        "z": "",
        "name": "Heating",
        "tab": "dee0def.c82102",
        "order": 1,
        "disp": true,
        "width": "6",
        "collapse": false
    },
    {
        "id": "dee0def.c82102",
        "type": "ui_tab",
        "z": "",
        "name": "Main",
        "icon": "dashboard",
        "order": 1,
        "disabled": false,
        "hidden": false
    }
]

```

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [8 March 2020 13:33 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788/2 "2020-03-08T13:33:04Z")

</div>

One possibility is an mqtt loop. Connect to the mqtt broker using a different client, such as mosqitto\_sub, and subscribe to "#" so you will see all traffic, and leave that running. See if anything obvious happens when it starts going wrong.

---

<div class="post-metadata">

**Author:** ![billiaz](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/billiaz/32/17921_2.png) [@billiaz](https://discourse.nodered.org/u/billiaz)\
**Post date:** [8 March 2020 14:37 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788/3 "2020-03-08T14:37:07Z")

</div>

It is not mqtt the  
mqtt in topic is different. And It was the first link to remove before testing the ui again.  
also using my MQTT explorer i've seen no traffic in mqtt side

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [8 March 2020 14:50 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788/4 "2020-03-08T14:50:34Z")

</div>

Does it fail with just that section of the flow that you exported enabled? If so then if there are not thousands of messages passing through then the only thing I can see that could be using the resources is the ui\_heater\_controller which I don't know anything about.

---

<div class="post-metadata">

**Author:** ![billiaz](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/billiaz/32/17921_2.png) [@billiaz](https://discourse.nodered.org/u/billiaz)\
**Post date:** [8 March 2020 14:54 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788/5 "2020-03-08T14:54:39Z")

</div>

It fails even manually injected objects (for testing and to avoid loops)  
I suspect memory heap or something similar..  
Can it be my flows.json is "contaminated" and causes this?

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [8 March 2020 14:57 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788/6 "2020-03-08T14:57:48Z")

</div>

Did you export the complete flow or is there lots more?  
Which process(s) are consuming the resources?  
How quickly does it fail?  
What do you mean by the flows file being contaminated?  
It might be worth posting the node-red startup log here, sometimes that is useful. Start node red in a terminal and post the log.

---

<div class="post-metadata">

**Author:** ![billiaz](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/billiaz/32/17921_2.png) [@billiaz](https://discourse.nodered.org/u/billiaz)\
**Post date:** [8 March 2020 15:18 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788/7 "2020-03-08T15:18:22Z")

</div>

It was full.  
once i set/change temp from ui it goes 100%. I rebuilt it and it doesn't do it.

also finalised it.. to control my thermostat for a room.

I take care of:

1. Avoid repeating the same message to MQTT if setTemp on thermostat and currentSetTemp is the same!
2. Added timeout in case it is Overridden by manual/user change (Adjustable with global variable)

Can I use on MQTT In/OUT variable as topic?  
If so maybe I can then use something like Subflow, to replicate mechanism on each room.

here is the final:

```auto
[
    {
        "id": "ebd56e5.ec86b9",
        "type": "tab",
        "label": "Hall First Flow",
        "disabled": false,
        "info": ""
    },
    {
        "id": "4398d66c.162748",
        "type": "mqtt in",
        "z": "ebd56e5.ec86b9",
        "name": "TRV CurrentTemp",
        "topic": "zwave2mqtt/HallwayFirst/TRV/49/1/1",
        "qos": "2",
        "datatype": "json",
        "broker": "90876955.0f6418",
        "x": 110,
        "y": 40,
        "wires": [
            [
                "1156e4a.3707d1b"
            ]
        ]
    },
    {
        "id": "6611a45c.a42f9c",
        "type": "ui_heater_controller",
        "z": "ebd56e5.ec86b9",
        "name": "Heater Hallway",
        "group": "fbed6f0b.6a621",
        "unit": "C",
        "order": 1,
        "width": 0,
        "height": 0,
        "topic": "",
        "title": "Hallway First",
        "logLengthType": "days",
        "logLength": "0",
        "sliderMinValue": 12,
        "sliderMaxValue": 28,
        "sliderStep": 0.5,
        "thresholdRising": 0.5,
        "thresholdFalling": 0.5,
        "calendar": "{\n \"Monday\": {\n \"00:00\": 19,\n \"06:20\": 22,\n \"08:00\": 19,\n \"16:40\": 22,\n \"23:59\": 19\n },\n \"Tuesday\": {\n \"00:00\": 19,\n \"06:20\": 22,\n \"08:00\": 19,\n \"16:40\": 22,\n \"23:59\": 19\n },\n \"Wednesday\": {\n \"00:00\": 19,\n \"06:20\": 22,\n \"08:00\": 19,\n \"16:40\": 22,\n \"23:59\": 19\n },\n \"Thursday\": {\n \"00:00\": 19,\n \"06:20\": 22,\n \"08:00\": 19,\n \"16:40\": 22,\n \"23:59\": 19\n },\n \"Friday\": {\n \"00:00\": 19,\n \"06:20\": 23,\n \"08:00\": 19,\n \"16:40\": 22,\n \"23:59\": 19\n },\n \"Saturday\": {\n \"00:00\": 19,\n \"08:00\": 20,\n \"20:00\": 22,\n \"23:59\": 19\n },\n \"Sunday\": {\n \"00:00\": 19,\n \"08:00\": 20,\n \"20:00\": 22,\n \"23:59\": 19\n }\n}",
        "x": 500,
        "y": 80,
        "wires": [
            [
                "4043672b.9b5ef8",
                "a8e2dfa0.23693"
            ]
        ]
    },
    {
        "id": "1156e4a.3707d1b",
        "type": "change",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "rules": [
            {
                "t": "set",
                "p": "topic",
                "pt": "msg",
                "to": "currentTemp",
                "tot": "str"
            },
            {
                "t": "set",
                "p": "payload",
                "pt": "msg",
                "to": "payload.value",
                "tot": "msg"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 300,
        "y": 40,
        "wires": [
            [
                "6611a45c.a42f9c"
            ]
        ]
    },
    {
        "id": "a8e2dfa0.23693",
        "type": "switch",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "property": "payload.targetValue",
        "propertyType": "msg",
        "rules": [
            {
                "t": "neq",
                "v": "currentSetTemp",
                "vt": "flow"
            }
        ],
        "checkall": "true",
        "repair": false,
        "outputs": 1,
        "x": 670,
        "y": 40,
        "wires": [
            [
                "152685af.aa1f6a"
            ]
        ]
    },
    {
        "id": "61949791.655088",
        "type": "change",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "rules": [
            {
                "t": "set",
                "p": "currentSetTemp",
                "pt": "flow",
                "to": "payload.value",
                "tot": "msg"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 430,
        "y": 320,
        "wires": [
            []
        ]
    },
    {
        "id": "26e241e0.01f89e",
        "type": "mqtt in",
        "z": "ebd56e5.ec86b9",
        "name": "TRV SetTemp",
        "topic": "zwave2mqtt/HallwayFirst/TRV/67/1/1",
        "qos": "1",
        "datatype": "json",
        "broker": "90876955.0f6418",
        "x": 130,
        "y": 300,
        "wires": [
            [
                "61949791.655088",
                "e789c9c0.fab848"
            ]
        ]
    },
    {
        "id": "4043672b.9b5ef8",
        "type": "change",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "rules": [
            {
                "t": "set",
                "p": "payload",
                "pt": "msg",
                "to": "payload.targetValue",
                "tot": "msg"
            },
            {
                "t": "set",
                "p": "#:(disk)::changeTimestamp",
                "pt": "flow",
                "to": "",
                "tot": "date"
            },
            {
                "t": "set",
                "p": "#:(disk)::isUserCustom",
                "pt": "global",
                "to": "payload.isUserCustom",
                "tot": "str"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 700,
        "y": 120,
        "wires": [
            []
        ]
    },
    {
        "id": "78177e54.cd333",
        "type": "inject",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "repeat": "300",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "x": 130,
        "y": 380,
        "wires": [
            [
                "687a69.d60d8598",
                "7ec87129.2d552",
                "e2bbf171.f1154"
            ]
        ]
    },
    {
        "id": "cda34824.2d2678",
        "type": "switch",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "property": "($flowContext(\"changeTimestamp\", \"disk\") + ($globalContext(\"heatingDelay\", \"disk\")*(60*60*1000) )) < payload",
        "propertyType": "jsonata",
        "rules": [
            {
                "t": "true"
            }
        ],
        "checkall": "true",
        "repair": false,
        "outputs": 1,
        "x": 430,
        "y": 380,
        "wires": [
            [
                "3c718ee3.0e7a22",
                "5d18d402.6fc84c"
            ]
        ]
    },
    {
        "id": "687a69.d60d8598",
        "type": "switch",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "property": "#:(disk)::isUserCustom",
        "propertyType": "flow",
        "rules": [
            {
                "t": "true"
            }
        ],
        "checkall": "true",
        "repair": false,
        "outputs": 1,
        "x": 290,
        "y": 380,
        "wires": [
            [
                "cda34824.2d2678",
                "d5c01eb2.0da33"
            ]
        ]
    },
    {
        "id": "3c718ee3.0e7a22",
        "type": "change",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "rules": [
            {
                "t": "set",
                "p": "topic",
                "pt": "msg",
                "to": "userConfig",
                "tot": "str"
            },
            {
                "t": "set",
                "p": "payload",
                "pt": "msg",
                "to": "{ \"isUserCustom\": false }",
                "tot": "json"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 660,
        "y": 380,
        "wires": [
            [
                "fac3d47d.2ed618"
            ]
        ]
    },
    {
        "id": "fac3d47d.2ed618",
        "type": "link out",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "links": [
            "94a3a152.08248"
        ],
        "x": 775,
        "y": 300,
        "wires": []
    },
    {
        "id": "94a3a152.08248",
        "type": "link in",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "links": [
            "fac3d47d.2ed618"
        ],
        "x": 355,
        "y": 80,
        "wires": [
            [
                "6611a45c.a42f9c"
            ]
        ]
    },
    {
        "id": "d5c01eb2.0da33",
        "type": "debug",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": true,
        "complete": "$flowContext(\"changeTimestamp\", \"disk\") + ($globalContext(\"heatingDelay\", \"disk\")*(60*60*1000) )",
        "targetType": "jsonata",
        "x": 480,
        "y": 460,
        "wires": []
    },
    {
        "id": "5d18d402.6fc84c",
        "type": "debug",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "active": true,
        "tosidebar": false,
        "console": false,
        "tostatus": true,
        "complete": "$flowContext(\"changeTimestamp\", \"disk\") + ($globalContext(\"heatingDelay\", \"disk\")*(60*60*1000) )",
        "targetType": "jsonata",
        "x": 760,
        "y": 440,
        "wires": []
    },
    {
        "id": "7ec87129.2d552",
        "type": "debug",
        "z": "ebd56e5.ec86b9",
        "name": "Override",
        "active": true,
        "tosidebar": false,
        "console": false,
        "tostatus": true,
        "complete": "$flowContext(\"isUserCustom\", \"disk\")",
        "targetType": "jsonata",
        "x": 460,
        "y": 520,
        "wires": []
    },
    {
        "id": "e2bbf171.f1154",
        "type": "debug",
        "z": "ebd56e5.ec86b9",
        "name": "Last Exec",
        "active": true,
        "tosidebar": false,
        "console": false,
        "tostatus": true,
        "complete": "$now()",
        "targetType": "jsonata",
        "x": 300,
        "y": 540,
        "wires": []
    },
    {
        "id": "509b298d.970c98",
        "type": "mqtt out",
        "z": "ebd56e5.ec86b9",
        "name": "updateTemp",
        "topic": "zwave2mqtt/HallwayFirst/TRV/67/1/1/set",
        "qos": "1",
        "retain": "",
        "broker": "90876955.0f6418",
        "x": 990,
        "y": 40,
        "wires": []
    },
    {
        "id": "e789c9c0.fab848",
        "type": "delay",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "pauseType": "delay",
        "timeout": "1",
        "timeoutUnits": "seconds",
        "rate": "1",
        "nbRateUnits": "1",
        "rateUnits": "second",
        "randomFirst": "1",
        "randomLast": "5",
        "randomUnits": "seconds",
        "drop": false,
        "x": 320,
        "y": 240,
        "wires": [
            [
                "8971020f.e4497"
            ]
        ]
    },
    {
        "id": "b122b16e.166aa",
        "type": "debug",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "false",
        "x": 740,
        "y": 220,
        "wires": []
    },
    {
        "id": "8971020f.e4497",
        "type": "function",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "func": "msg.topic = \"userConfig\"\nmsg.payload = {\"Temp\": msg.payload};\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "x": 540,
        "y": 240,
        "wires": [
            [
                "b122b16e.166aa"
            ]
        ]
    },
    {
        "id": "152685af.aa1f6a",
        "type": "change",
        "z": "ebd56e5.ec86b9",
        "name": "",
        "rules": [
            {
                "t": "set",
                "p": "payload",
                "pt": "msg",
                "to": "payload.targetValue",
                "tot": "msg"
            }
        ],
        "action": "",
        "property": "",
        "from": "",
        "to": "",
        "reg": false,
        "x": 820,
        "y": 40,
        "wires": [
            [
                "509b298d.970c98"
            ]
        ]
    },
    {
        "id": "90876955.0f6418",
        "type": "mqtt-broker",
        "z": "",
        "name": "Main MQTT",
        "broker": "mqtt",
        "port": "1883",
        "clientid": "",
        "usetls": false,
        "compatmode": false,
        "keepalive": "60",
        "cleansession": true,
        "birthTopic": "",
        "birthQos": "0",
        "birthPayload": "",
        "closeTopic": "",
        "closeQos": "0",
        "closePayload": "",
        "willTopic": "",
        "willQos": "0",
        "willPayload": ""
    },
    {
        "id": "fbed6f0b.6a621",
        "type": "ui_group",
        "z": "",
        "name": "Heating",
        "tab": "dee0def.c82102",
        "order": 1,
        "disp": true,
        "width": "8",
        "collapse": false
    },
    {
        "id": "dee0def.c82102",
        "type": "ui_tab",
        "z": "",
        "name": "Main",
        "icon": "dashboard",
        "order": 1,
        "disabled": false,
        "hidden": false
    }
]

```

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [8 March 2020 15:22 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788/8 "2020-03-08T15:22:00Z")

</div>

> [@billiaz](#):
>
> Can I use on MQTT In/OUT variable as topic?

Please explain what you mean

---

<div class="post-metadata">

**Author:** ![billiaz](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/billiaz/32/17921_2.png) [@billiaz](https://discourse.nodered.org/u/billiaz)\
**Post date:** [8 March 2020 15:28 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788/9 "2020-03-08T15:28:05Z")

</div>

My MQTT topic (the device payload) is  
zwave2mqtt///

can this become a variable? and used in the topic field of mqtt ndoe?

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [8 March 2020 15:34 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788/10 "2020-03-08T15:34:41Z")

</div>

> [@billiaz](#):
>
> My MQTT topic (the device payload) is  
> zwave2mqtt///

Do you mean the value received when you subscribe to some mqtt topic is the string "zwave2mqtt///" and you want that to be used as an mqtt topic? I am not sure that would be a valid topic, but apart from that then I suppose so. Why would you want to do that though? Do you want to subscribe to it or publish. Publish is easy as you can pass the topic to the MQTT out node. Subscribe is not so easy, you would need to subscribe with wildcards to get all such topics then filter it in the flow.

---

<div class="post-metadata">

**Author:** ![billiaz](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/billiaz/32/17921_2.png) [@billiaz](https://discourse.nodered.org/u/billiaz)\
**Post date:** [8 March 2020 15:36 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788/11 "2020-03-08T15:36:47Z")

</div>

for some reason the \< and \> been removed  
topic can be zwave2mqtt/DeviceLoc/DeviceName/Payload  
the DeviceLoc or DeviceName can be variable

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [8 March 2020 15:46 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788/12 "2020-03-08T15:46:42Z")

</div>

You need to put special chars in backticks in the forum, otherwise it interprets them as markup codes.  
You can subscribe to topics like  
`wave2mqtt/+/+/Payload`  
and that will subscribe to all topics where `+` is anything. Or you can subscribe to  
`wave2mqtt/#`  
and that will subscribe to anything starting with `wave2mqtt/`

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [7 May 2020 15:46 UTC](https://discourse.nodered.org/t/100-cpu-when-touching-ui-or-a-specific-flow-reloads/22788/13 "2020-05-07T15:46:43Z")

</div>

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