Result of influxDB#write()

[drb-digital]

Hi Stefan,

first of all thanks for your great work on InfluxDB implementation for java. Including your commits from the last days it is working quite well in my 0.9.0 environment.

I was wondering if there is any possibility to get the result of writing a point (or batched points) to database? Somehow like boolean true/false. I'd like to store my data locally if there is any error (e.g. no connection) and try again later.

Thanks,
Dennis

[majst01]

Hi Dennis,

the write is as long as you did not enable batchMode a synchronous call which will throw a RuntimeException if something went wrong, so you will notice it in you app.

If batchMode is enabled, this exception will be thrown in the flusher thread.
I dont see how we could change this behaviour in a way you will get informed about write errors.

Any hints welcome
Stefan

[drb-digital]

Hi Stefan,

thanks for your reply. Unfortunately I am using batch mode. I'll give it some thought and let you know if I am coming any closer to a possible solution.

One more thing: I am using strings containing lineProtocol to store points/batch points locally. But as far as I can see there is no method to write lineProtocol instead of points/batch points. I tried using query instead, but that wasn't working for me. So I implemented an additional method to InfluxDBImpl.java. I think this is useful for others too, so probably you could include some method like this.

Dennis

public void write(final String database, final String retentionPolicy, final String getLineProtocol) {
        TypedString lineProtocol = new TypedString(getLineProtocol);
        this.influxDBService.writePoints(
                this.username,
                this.password,
                database,
                retentionPolicy,
                TimeUtil.toTimePrecision(TimeUnit.NANOSECONDS),
                ConsistencyLevel.ONE.toString(),
                lineProtocol);

    }

[majst01]

Hi,
do you have any special requirements to the content of the lineprotocol which are not fulfilled with the implementation present in Point.java ? If yes please describe these and i will try to implement. Otherwise i want to keep the API as small as possible because this keeps the implementation simple with fewer bugs.

Greetings
Stefan

[drb-digital]

Hi Stefan,

no, Point.java is allright. What I want to achieve is the following. My influxdb instance is running on a server, data is collected on a mobile device. Every time an exception is thrown, I am storing the point which haven't been sent to influxdb to a local SQLite database. Therefore I am using the method Point#lineProtocol(), which is working fine.

try {
  InfluxDB influxDB = InfluxDBFactory.connect(dbUrl, dbUser, dbPassword);
  influxDB.write(dbName, dbRetentionPolicy, point);
} catch (Exception e) {
  DatabaseSQLite databaseSQLite = new DatabaseSQLite();
  databaseSQLite.openConnection();
  databaseSQLite.insertLineProtocol(point.lineProtocol());
  databaseSQLite.closeConnection();
}

What I am missing is a possibility to send these stored points to influxdb after retrieving them from local database. Therefore I implemented the method mentioned in my comment above and use it as follows:

DatabaseSQLite databaseSQLite = new DatabaseSQLite();
databaseSQLite.openConnection();
String lineProtocol = databaseSQLite.getLineProtocol(id);
databaseSQLite.closeConnection();

InfluxDB influxDB = InfluxDBFactory.connect(dbUrl, dbUser, dbPassword);
influxDB.write(dbName, dbRetentionPolicy, lineProtocol);

Another solution would be to convert lineProtocol strings back to points, which could then be sent by the already existing API.

Hope this explanation helps.

Greetings
Dennis

[majst01]

Hi Dennis,

ok got it, but why not serialize/deserialize The Point instance which failed to json and back to a instance for example with GSON:

Gson gson = new Gson();
String pointAsJson = gson.toJson(point);  
// persist to SQLite
Point point = gson.fromJson(pointAsJson,Point.class);  
// persist in influxdb

IMHO lineprotocol is not a proper serialization of points.

[majst01]

Close this ticket because there seem to be urgent demand.

[drb-digital]

Hi Stefan,

sorry for the delayed reply. That was my first guess too. But when I used JSON parser by Jackson execution failed every time (I cant't remember the error message, but it was something like error while building json from Point). Therefore I was looking into the lineProtocol and didn't try GSON. I'll gave it a try now and it seems to work pretty well. Thanks for your hint!

Greetings
Dennis

[Danushka96]

Hi Stefan,

Is there a way to catch the exceptions while writing to influx in batch mode in the newer versions of Influx?

[majst01]

Yes please read the documentation carefully.

[Danushka96]

Got it, Thanks @majst01