Bokeh + Flask: Multiple AjaxDataSource Calls

Question

A Bokeh object is a number that shows 3 independent lines.

Data is streamed. The AjaxDataSource call updates data every 5 seconds, reading the latest from the database.

This is a split class:

class Graph:
    def __init__(self):

        data_source = AjaxDataSource(data=dict(date_time=[],
                                               value_1=[], 
                                               value_2=[], 
                                               value_3=[]), 
                                               data_url="/data",
                                               polling_interval=5000)

        line1 = self.figure.line(x="date_time", y="value_1", source=data_source)
        line2 = self.figure.line(x="date_time", y="value_2", source=data_source)
        line3 = self.figure.line(x="date_time", y="value_3", source=data_source)

        app.add_url_rule("/data", "/data", self.serve, methods=['GET', 'OPTIONS', 'POST'])

    def serve(self):

        # load data from db and return JSON
        ...
        return jsonify(
            date_time= da.df["Date_Time"].tolist(),
            value_1=da.df["Value1"].tolist(),
            value_2=da.df["Value2"].tolist(),
            value_3=da.df["Value3"].tolist()
        )

date_timeis the common x axis, value_1for row 1, value_2for row 2, value_3for row 3.

Problem

Why AjaxDataSourceis it called 3 times (they are a few milliseconds from each other, then triple reading is performed after 5 seconds), and not only once every 5 seconds?

I believed that the AjaxDataSource is dynamically populated data_source.dataevery 5 seconds, and then, after they have been read, 3 lines read this "static" data.

Workaround

AjaxDataSource, ColumnDataSource "" ?

- ?

Answer 1

, , , . AjaxDataSource .

: https://github.com/bokeh/bokeh/issues/6736

, :

Bokeh.require('models/sources/ajax_data_source').AjaxDataSource.prototype.setup = function () {
    this.get_data(this.mode);
    if (this.polling_interval && this.interval == null) {
        return this.interval = setInterval(this.get_data, this.polling_interval, this.mode, this.max_size, this.if_modified);
    }
}

, , Bokeh , . , , Bokeh.