InfluxDB write failed: connection failed

[ewwachter]

Steps to reproduce:
I've tried to reproduce the basic write example: https://github.com/tobiasschuerg/InfluxDB-Client-for-Arduino/blob/master/examples/BasicWrite/BasicWrite.ino
I fulfilled the information, INFLUXDB_URL, INFLUXDB_TOKEN, INFLUXDB_TOKEN, INFLUXDB_ORG and INFLUXDB_BUCKET.

Expected behavior:
I would expect wifi connected and influxDB connect
Actual behavior:
Wifi is connected, but influxdb has error:
InfluxDB connection failed: connection failed
Writing: wifi_status,device=ESP8266,SSID= rssi=-84i
InfluxDB write failed: connection failed
Wait 10s

Specifications:

• Library Version: latest
• InfluxDB Version: 2
• Board/ESP chip: ESP8266 Feather Huzzah board
• Device Arduino SDK version: 2.0.3

[vlastahajek]

@ewwachter, make sure you have the correct Server URL, not http://localhost:8086.
If you are still unsure, enable debug and add a log, please.

[ewwachter]

Hi, thanks for the update, please see the log:

6.509 [D] Org: removed
6.512 [D] Bucket: removed
6.515 [D] Token: removed
6.524 [D] DB version: 2
6.527 [D] probeMaxFragmentLength to us-east-1-1.aws.cloud2.influxdata.com:443
6.744 [D] MFLN:yes
6.745 [D] setUrls
6.745 [D] writeUrl: https://us-east-1-1.aws.cloud2.influxdata.com/api/v2/write?org=removed&bucket=removed
6.748 [D] queryUrl: https://us-east-1-1.aws.cloud2.influxdata.com/api/v2/query?org=removed
6.756 [D] Validating connection to https://us-east-1-1.aws.cloud2.influxdata.com/health
6.764 [D] GET request - https://us-east-1-1.aws.cloud2.influxdata.com/health
8.247 [E] Error - connection failed
8.248 [D] error -1: connection failed
InfluxDB connection failed: connection failed
9.250 [D] writeRecord: bufferPointer: 1, batchPointer: 0, _bufferCeiling: 1
9.251 [D] Flushing buffer: is oversized true, is timeout false, is buffer full false
9.255 [D] Writing batch, batchpointer: 0, size 1
9.260 [D] Writing to https://us-east-1-1.aws.cloud2.influxdata.com/api/v2/write?org=removed&bucket=removed
9.271 [D] Sending:
9.279 [D] POST request - https://us-east-1-1.aws.cloud2.influxdata.com/api/v2/write?org=removed&bucket=removed, data: 81bytes, type text/plain
10.795 [D] HTTP status code - -1
10.796 [E] Error - connection failed
10.797 [D] error -1: connection failed

Please note that I've removed/replaced token, org, bucket values

[vlastahajek]

As you are using HTTPS you should have started with the SecureWrite example. Your code most probably fails due to certificate validation.
Add these lines before validating connection:

  // Accurate time is necessary for certificate validation and writing in batches
  // For the fastest time sync find NTP servers in your area: https://www.pool.ntp.org/zone/
  // Syncing progress and the time will be printed to Serial.
  timeSync(TZ_INFO, "pool.ntp.org", "time.nis.gov");

  // Alternatively, set insecure connection to skip server certificate validation 
  //client.setInsecure();

[ewwachter]

I see. What should I define as TZ_INFO? I cannot find this information. I'm currently based in the UK

[vlastahajek]

Set timezone string according to https://www.gnu.org/software/libc/manual/html_node/TZ-Variable.html
Examples:

• Pacific Time: "PST8PDT"
• Eastern: "EST5EDT"
• Japanesse: "JST-9"
• Central Europe: "CET-1CEST,M3.5.0,M10.5.0/3"

#define TZ_INFO "CET-1CEST,M3.5.0,M10.5.0/3"

[ewwachter]

I've tried with Central Europe: "CET-1CEST,M3.5.0,M10.5.0/3" and it gives the same error, but now I can see the Synchronized time: Tue Apr 11 17:19:53 2023

Which is central europe and not the UK one. Can this be the issue? How can I find the TZ_INFO for UK?

[ewwachter]

I did manage to change the timezone:

#define TZ_INFO "GMT0BST,M3.5.0/1,M10.5.0/2"

Now I get the correct datetime, but still got the same error

[vlastahajek]

Arduino Core for ESP8266 has a nice set of TZ constants: https://github.com/esp8266/Arduino/blob/master/cores/esp8266/TZ.h.
Try adding client.setInsecure(), please.

[ewwachter]

It works! Many thanks.

So, essentially for some reason it is not working securely? is that the issue?

[vlastahajek]

It looks like the default included certificate doesn't work now. I will check later. You can add the new server certificate in your app if needed: https://github.com/tobiasschuerg/InfluxDB-Client-for-Arduino#secure-connection

[SPX10SF]

Hi , @vlastahajek I m having the same issue using an ESP8266 running the basic write example , the error message is 01:56:34.755 -> 165.421 [D] POST request - http://192.168.0.31:8086/api/v2/write?org=9195xxxxxxxxf&bucket=ESP8266, data: 68bytes, type text/plain
01:56:34.755 -> [hostByName] Host: 192.168.0.31 is IP!
01:56:34.755 -> 170.439 [D] HTTP status code - -1
01:56:34.755 -> 170.440 [E] Error - connection failed
01:56:34.755 -> 170.440 [D] error -1: connection failed
01:56:34.755 -> 170.441 [D] Leaving data in buffer for retry, retryInterval: 0
01:56:34.755 -> 170.444 [D] Success: 0, _bufferPointer: 1, _batchPointer: 1, _writeBuffer[_bufferPointer]_0x3fff0fac
01:56:34.755 -> InfluxDB write failed: connection failed

Thank you very much for any support on this

[vlastahajek]

@SPX10SF, there must be a connection problem between the ESP and the server. Check if you can reach the server from a different computer (e.g. from a mobile phone try load UI at http://192.168.0.31:808

[SPX10SF]

Hi @vlastahajek , you re right , i m not able to access from a mobile phone . Mobile phone and computer are connected to the same wifi network . Looks like computer firewall is closing 8086 port . Thank you very much for your help !