(/usr/lib/node_modules/node-red/node_modules/@node-red/runtime/lib/flows/Flow.js:679:52)
Nov 18 18:50:51 ubuntu-nuc Node-RED[23840]: at processImmediate (internal/timers.js:464:21)
```
Using node-red-contrib-gc I have created a memory heap usage graph in my Node-RED application dashbord. Here is how it looks for now after restarting Node-RED service yesterday around 8:40PM MSK:
I.e. within less then 24 hours almost 500MBytes leaked.
I was able to duplicate possible memory leak warning on my test machine using the following flow:
As soon as new users can't upload files, flow.json can be downloaded from [here](https://yadi.sk/d/ypzTvhe5Uy-cWg) if necessery.
5th or 6th click on middle inject button causes memory leak warning in system log.
Looking through source code in **.node-red/node\_modules/node-red-node-mysql/68-mysql.js** I see the line 77, which, I guess, is responsible for memory releasing, is commented out:
```auto
this.on('close', function(done) {
if (this.tick) { clearTimeout(this.tick); }
if (this.check) { clearInterval(this.check); }
node.connected = false;
// node.connection.release();
node.emit("state"," ");
node.pool.end(function(err) { done(); });
});
```
Can this be the reason of memory leak? Something tells me that closed connection will never be used again and should be released.
I use the following configuration:
**Operating system** : Ubuntu Linux Server v.20.04.3
**Node-RED version:** v2.0.6 (my Node-RED app), v2.1.3 (test)
**Node.js version:** v14.18.1
Thanks,
Sergey
---
### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [19 November 2021 15:17 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/2 "2021-11-19T15:17:56Z")
How often are you writing to the database?
Is the flow you show the only access to the database in node-red?
What specifically suggests to you that it is the MySql node causing the problem?
---
### Author:  [@dceejay](https://discourse.nodered.org/u/dceejay)
#### Post date: [19 November 2021 15:23 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/3 "2021-11-19T15:23:39Z")
The mysql message is more a warning than reality... but there is a recent thread with a beta release you are welcome to try that does fix that [[Feedback wanted] Update to mysql node](https://discourse.nodered.org/t/feedback-wanted-update-to-mysql-node/53936)
(though I do suspect the real cause is most likely elsewhere)
---
### Author:  [@ls819011](https://discourse.nodered.org/u/ls819011)
#### Post date: [19 November 2021 15:43 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/4 "2021-11-19T15:43:37Z")
1. My Node-RED application writes ~3-6 times per minute, but 3 of them are very close to each other;
2. In aplication I have two mysql nodes in two flows, in test flow there is only one node in only one flow;
3. a) I have similar app on my home Orange Pi which uses the same nodes but don't writes to database and it do not chash;
b) warning trace points to mysql;
c) getting memory leak warning in syslog on 5-6th click in test flow while MaxListeners is set to 10 by default, I suspect that each click creates 2 listeners and listeners are not releasing after use.
---
### Author:  [@ls819011](https://discourse.nodered.org/u/ls819011)
#### Post date: [19 November 2021 15:44 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/5 "2021-11-19T15:44:30Z")
What about commented line 77 in 68-mysql.js?
---
### Author:  [@dceejay](https://discourse.nodered.org/u/dceejay)
#### Post date: [19 November 2021 15:52 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/6 "2021-11-19T15:52:17Z")
We are now using the pool of connections so the end should clean them all up...
---
### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [19 November 2021 15:53 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/7 "2021-11-19T15:53:50Z")
> [@ls819011](#):
>
> getting memory leak warning
It isn't a memory leak warning.
> [@ls819011](#):
>
> In aplication I have two mysql nodes in two flows, in test flow there is only one node in only one flow;
Do you mean that you have nothing else running in node-red except that flow?
Did you try the beta version suggested?
---
### Author:  [@ls819011](https://discourse.nodered.org/u/ls819011)
#### Post date: [19 November 2021 16:23 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/8 "2021-11-19T16:23:15Z")
> [@Colin](#):
>
> It isn't a memory leak warning.
Ok. It is "MaxListenersExceededWarning: **Possible** EventEmitter **memory leak detected.**"
> [@Colin](#):
>
> Do you mean that you have nothing else running in node-red except that flow?
Yes. Nothing except this test flow.
> [@Colin](#):
>
> Did you try the beta version suggested?
Not yet.
---
### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [19 November 2021 16:24 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/9 "2021-11-19T16:24:42Z")
> [@ls819011](#):
>
> Nothing except this test flow.
And running that test flow eventually gives you the memory crash?
---
### Author:  [@ls819011](https://discourse.nodered.org/u/ls819011)
#### Post date: [19 November 2021 16:26 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/10 "2021-11-19T16:26:27Z")
> [@Colin](#):
>
> And running that test flow eventually gives you the memory crash?
No. 5-6th click on middle inject button gives me "MaxListenersExceededWarning: **Possible** EventEmitter **memory leak detected.**"
---
### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [19 November 2021 16:30 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/11 "2021-11-19T16:30:32Z")
But does it crash node-red after an extended period? That is the problem that needs to be fixed.
Almost certainly the Listeners message is not the cause of the crash, since you are only writing a few times a minute to the database, particularly since you are only writing a small amount of information each time (the vmstats).
---
### Author:  [@ls819011](https://discourse.nodered.org/u/ls819011)
#### Post date: [19 November 2021 17:27 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/12 "2021-11-19T17:27:19Z")
> [@dceejay](#):
>
> ... but there is a recent thread with a beta release you are welcome to try that does fix that
Installed node-red-node-mysql@1.0.0-beta-2 using `cd ~/.node-red && npm i node-red-node-mysql@next` command. Restarted Node-RED service but I still see node-red-node-mysql 0.3.0 in Node-RED editor palette.
Is that Ok?
---
### Author:  [@dceejay](https://discourse.nodered.org/u/dceejay)
#### Post date: [19 November 2021 17:28 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/13 "2021-11-19T17:28:27Z")
no - it should show the correct version (as long as you reloaded the page also)
---
### Author:  [@ls819011](https://discourse.nodered.org/u/ls819011)
#### Post date: [19 November 2021 18:20 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/14 "2021-11-19T18:20:09Z")
> [@dceejay](#):
>
> no - it should show the correct version (as long as you reloaded the page also)
Everything is Ok after page reloading. I was **not** able to get MaxListenersExceededWarning clicking on inject button in my test application.
After upgrading mysql node in main application to v1.0.0-beta2 I did't get this warning within 20 minutes after Node-RED restart. This application bulds memory heap usage graph. I will provide it to you after 24 hours running.
Thanks a lot.
---
### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [19 November 2021 18:36 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/15 "2021-11-19T18:36:26Z")
If you are still getting the crash then tell us more about what you are doing. Are you manipulating any large data items? Possibly photos or videos, or fetching large numbers of rows from your db, or reading large files.
Also tell us about any additional nodes you have installed. Check in manage palette to see what you have installed.
---
### Author:  [@ls819011](https://discourse.nodered.org/u/ls819011)
#### Post date: [20 November 2021 17:55 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/16 "2021-11-20T17:55:27Z")
@dceejay, unfortunately I can't provide you 24-hours graph due to power outage I had at location where my app is running. UPS battery died before power was restored. But looking on last 12 hours graph I can state that memory leak is fixed by v1.0.0-beta-2:
Memory leak gone away. Thank you. But I got another issue (see [here](https://discourse.nodered.org/t/feedback-wanted-update-to-mysql-node/53936/6)).
---
### Author:  [@dceejay](https://discourse.nodered.org/u/dceejay)
#### Post date: [20 November 2021 20:13 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/17 "2021-11-20T20:13:09Z")
expect beta3 sometime tomorrow (probably)
(uodate) - now republished with decimalNumbers flag set true
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [4 December 2021 20:13 UTC](https://discourse.nodered.org/t/node-red-node-mysql-0-3-0-is-causing-a-memory-leak/53999/18 "2021-12-04T20:13:19Z")
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