How can I know errors like ConnectionTimeoutException in chunked query?

[MichaelHai]

When I tried to execute a chunked query, it looks like no way to know about the query is failed because of errors like ConnectionTimeoutException. Since the chunked query is executed in an async way, my consumer cannot know about whether the query is finished or not so it can only keep waiting. Here is my code:

influxDB.query(query, chunkSize, queryResult -> {
            // Tricky solution in influxdb-java to singal the end of the stream
            // Refs: https://github.com/influxdata/influxdb-java/pull/270
            // Possible Future Improvement: https://github.com/influxdata/influxdb-java/issues/515
            try {
                if (queryResult.getError() != null) {
                    if (queryResult.getError().equals("DONE")) {
                        allFetched.finish();
                    } else {
                        errorHandler.accept(new RuntimeException(queryResult.getError()));
                    }
                } else {
                    InfluxDBResultMapper resultMapper =
                        new InfluxDBResultMapper();
                    consumer.accept(resultMapper.toPOJO(
                        queryResult,
                        consumedClass
                    ));
                }
            } catch (Exception ex) {
                errorHandler.accept(ex);
            }
        });

I haved looked into the code of influxdb-java and okhttp3. In influxdb-java, the failure callback do nothing but throw back the exception from okhttp3 like this:

            public void onFailure(Call<ResponseBody> call, Throwable t) {
                throw new InfluxDBException(t);
            }

And in okhttp3, for failure callback who also throws exception, it just print the stacktrace and finished. In this case, my consumer is not called at all and it looks no way to know about such failure in my code.

                public void onFailure(okhttp3.Call call, IOException e) {
                    this.callFailure(e);
                }

                private void callFailure(Throwable e) {
                    try {
                        callback.onFailure(OkHttpCall.this, e);
                    } catch (Throwable var3) {
                        var3.printStackTrace();
                    }

                }

[rhajek]

I think, this issue is a bug, there is no way how to handle this error.
I prepared the pull request for 2.14 that solves this by adding onFailure consumer into chunking query API. There is also possibility to cancel processing in any time and handle error without queryResult.getError().equals("DONE") hack.

influxDB.query(query, chunksize,
        //onNext result consumer
        (cancellable, queryResult) -> {
            System.out.println("Process queryResult - " + queryResult.toString());
        }
        //onComplete executable
        , () -> {
            System.out.println("On Complete - the query finished successfully.");
        },
        //onFailure error handler
        throwable -> {
            System.out.println("On Failure - " + throwable.getLocalizedMessage());
        });
    

[MichaelHai]

Get it. Thank you for the fixing.