Issue in History Graph CSV Download

I am running blynk laster version 0.27.1 on my local server(Ubuntu server). Most of the things are works fine. Now I am getting the issue on History Graph CSV Download. When I click the “Export to CSV” button it takes me to Export data popup message and the popup message says “CSV file will be sent to your email address” and once I clicked the continue button then it says “No Data”

Note: I have installed postfix on my local server and enabled following values on my file

#enable DB

#enable raw data storage to DB


Hello. Do you have selected pins in your history graph?

Yes, I have configured 2 pins V1 and V2. Aso, I am getting the graph on history graph. Only problem if I try to export CSV file.

Did you put your email credentials to

Yes, and other emails are getting from servers. Example once you created the new device then I will get the token through the email.

Do you see any errors in logs? Do you have latest app? Android?

No, I didn’t get an error in the blynk.log file. Anyway, this is the log when I click the export CSV from history graph

08:59:03.627 TRACE- Incoming GetGraphDataStringMessage{id=12, command=GetGraphDataRequest, length=43, body=‘1561317523v11440mv21440mv31440m’}
08:59:03.650 TRACE- Incoming GetGraphDataStringMessage{id=13, command=GetGraphDataRequest, length=43, body=‘1561317523v11440mv21440mv31440m’}
08:59:03.650 TRACE- Incoming GetGraphDataStringMessage{id=14, command=GetGraphDataRequest, length=43, body=‘1561317523v11440mv21440mv31440m’}
08:59:16.468 TRACE- Incoming ExportGraphData{id=15, command=ExportGraphData, length=19, body=‘1561317523-0176803’}

Yes, I have the latest version of Blynk android on my mobile. App Version 2.15.1

Hm… That’s interesting. Do you see any error in postgres.log? Also did you try to make export via HTTP API? Does it work for you?

postgres.log log I didn’t get any error.
I didn’t check the export via HTTP API. Let me check this and update you.

I can’t able to get the history graph data through the HTTP API. I am getting following error in the blynk.log file.

Curl request:

curl --include ‘`masked token`/data/V2’


HTTP/1.1 400 Bad Request
connection: keep-alive
content-type: text/plain;charset=utf-8
access-control-allow-origin: *
content-length: 23

Error getting pin data.

Error log

07:03:40.305 DEBUG- In http and websocket unificator handler.
07:03:40.305 DEBUG- GET : //data/V2
07:03:40.305 DEBUG- Re registering http channel. [id: 0xeb0035d4, L:/ - R:/]
07:03:40.306 DEBUG- Error getting pin data.
07:03:40.306 DEBUG- Re registering http channel finished.

If I tried to get the PIN value through HTTP API then it works

Curl request:

curl --include ‘`masked token`/get/V2’


HTTP/1.1 200 OK
connection: keep-alive
content-type: application/json;charset=utf-8
access-control-allow-origin: *
content-length: 10


Hm… Thanks. Do you have enough space on your disk? Maybe process doesn’t have access rights to write to the temporary directory on your system?

If above not a case for you - I’ll provide you with debug build so we could see exact error.

@maheshio hello. any update?

Yes, I have lots of free space in my local blynk server.

Usually, anyone can write data in /tmp directory. Also, I can see history data’s are written in the data folder. So I don’t think writing is causing the issue.

If possible you can give the debug build I can try with this.


I think I found the problem. Problem coming from /tmp/blynk directory. Actually, this folder has root uer access but I am runing blynk on another user. So, its my mistake.

Thanks for your hlep.

1 Like