useServerTimestamp does not work with non-default precisions

[szerwi]

It seems that useServerTimestamp does not work with precisions other than default.

List the minimal actions needed to reproduce the behavior.

1. Set useServerTimestamp(true) and writePrecision(WritePrecision::S)
2. Send point

Expected behavior:
Timestamp from server should be used

Actual behavior:
Timestamp is invalid - point is placed with 01-01-1970 timestamp

Specifications:

• Library Version: 3.13.0
• InfluxDB Version: 2.6.1
• Board/ESP chip: ESP32 Dev Module
• Device Arduino SDK version: arduino-esp32 2.0.6

[vlastahajek]

@szerwi, How do you set those options exactly?

[szerwi]

@vlastahajek Here is my setup:

influxdb.setWriteOptions(WriteOptions()
  .writePrecision(WritePrecision::S)
  .useServerTimestamp(true)
  .batchSize(1)
  .bufferSize(2)
  .flushInterval(30)
  .retryInterval(1)
  .maxRetryInterval(2)
  .maxRetryAttempts(0)
  );
influxdb.setHTTPOptions(HTTPOptions().httpReadTimeout(6000).connectionReuse(true));
influxdb.setConnectionParams(INFLUXDB_URL, INFLUXDB_ORG, INFLUXDB_BUCKET, INFLUXDB_TOKEN);
influxdb.setInsecure(true);

if (influxdb.validateConnection()) {
  Serial.print("Connected to InfluxDB: ");
  Serial.println(influxdb.getServerUrl());
} else {
  Serial.print("InfluxDB connection failed: ");
  Serial.println(influxdb.getLastErrorMessage());
}

[vlastahajek]

This is absolutely correct and it shouldn't cause sending a zero timestamp. That could happen only when using deprecated bool setWriteOptions(WritePrecision precision, uint16_t batchSize = 1, uint16_t bufferSize = 5, uint16_t flushInterval = 60, bool preserveConnection = true)
Could you, please, enable the debug output in the src/util/debug.h and check the sent data if it really sends 0?

[szerwi]

@vlastahajek Sorry for the late reply.

I can confirm that timestamp is being sent when I set writePrecision(WritePrecision::S) together with useServerTimestamp(true). It sends the timestamp in seconds. My ESP is not connected to NTP, so it starts counting the timestamp from 0.

Debug output with writePrecision(WritePrecision::S) and useServerTimestamp(true):

30.000 [D] writeRecord: bufferPointer: 1, batchPointer: 0, _bufferCeiling: 1
30.011 [D] Flushing buffer: is oversized true, is timeout false, is buffer full false
30.011 [D] Writing batch, batchpointer: 0, size 1
30.021 [D] Writing to https://xxx:55555/api/v2/write?org=xxx&bucket=xxx&precision=s
30.032 [D] Sending:
snow_depth snow_depth_mean=5.0,snow_depth_median=5.0 30

30.032 [D] POST request - https://xxx:55555/api/v2/write?org=xxx&bucket=xxx&precision=s, data: 56bytes, type text/plain
31.283 [D] HTTP status code - 204
31.285 [D] Dropped batch, batchpointer: 1
31.285 [D] Success: 1, _bufferPointer: 1, _batchPointer: 1, _writeBuffer[_bufferPointer]_0x0
31.295 [D] Buffer empty

Debug output with only useServerTimestamp(true):

15.000 [D] writeRecord: bufferPointer: 1, batchPointer: 0, _bufferCeiling: 1
15.011 [D] Flushing buffer: is oversized true, is timeout false, is buffer full false
15.011 [D] Writing batch, batchpointer: 0, size 1
15.021 [D] Writing to https://xxx:55555/api/v2/write?org=xxx&bucket=xxx
15.021 [D] Sending:
snow_depth snow_depth_mean=5.0,snow_depth_median=5.0

15.032 [D] POST request - https://xxx:55555/api/v2/write?org=xxx&bucket=xxx, data: 53bytes, type text/plain
16.287 [D] HTTP status code - 204
16.289 [D] Dropped batch, batchpointer: 1
16.289 [D] Success: 1, _bufferPointer: 1, _batchPointer: 1, _writeBuffer[_bufferPointer]_0x0
16.300 [D] Buffer empty

[vlastahajek]

Thanks, @szerwi, for the details, and sorry for the late reply. Supporting this library was part of my previous job and I have now trouble finding time for this.
The core problem here is if connection params are not set in the constructor (which is the way most often used to set it), it must be set before any options are set, because setting of options initializes internals and this requires a valid server URL.
You will notice a problem by checking the return values of options setters.

I admit this is not much intuitive and I will fix this.