Can't join more than two series, and even those return empty results

[kinghajj]

The documentation states rather definitively "Joins will put two or more series together." So, I wrote a tiny node.js script to write the results of os.cpus() once a second. At first I put each CPU's data into a separate series, and then tried to join them to make a continuous query with their aggregate data

select cpu0.idle + cpu1.idle + cpu2.idle + cpu3.idle from cpu0 inner join cpu1 inner join cpu2 inner join cpu3

To my dismay, however, this query did not parse! Looking at the code made it clear why: the grammar currently only allows a two series to be joined.

Looking at the examples, I decided to restructure the database so that there is one table, "cpus", with an additional column "cpu" for the cpu ID. I then tried to do a simple join like this

select cpu0.idle + cpu1.idle from cpus as cpu0 inner join cpus as cpu1 where cpu0.cpu = 0 and cpu1.cpu = 1

...and got back an empty list! My script explicitly sets the time column for each point, so for each unique time there is an row for every CPU id. Any idea on why this join is failing to produce any useful results?

Here's the current script:

var influx = require('influx');
var os = require('os');

var client = influx({
    host: 'influxdb-test',
    port: 8086,
    username: 'dbuser',
    password: 'password',
    database: 'example'
});

setInterval(function () {
    var now = new Date().getTime();
    var cpuInfos = os.cpus();
    for (var i in cpuInfos) {
        var point = cpuInfos[i].times;
        point.time = now;
        point.cpu = parseInt(i);
        client.writePoint('cpus', point, function (err) {
            if (err) throw err;
        });
    }
}, 1000);

[Pavel---L]

It's said in docs that we can join multiple series. In practice I can join only two series. When I try to join more than two series I'm always get syntax error. Could you please give a valid syntax for multi series joins?

[kawikao]

+1. Not a deal killer but it would save a lot of collector hacking to combine on the client side. Thanks

[jemc]

This is currently keeping me from being able to calculate an application's Apdex score and display it in Grafana, because the Apdex formula uses three variables (see http://apdex.org/overview.html) and I get a syntax error when trying to join three series.

[jemc]

@beckettsean - For completeness' sake, can you explain how this is obsoleted by v0.9.0?

[beckettsean]

JOIN is no longer a concept in 0.9. Series sharing a measurement can be queried together simply by omitting the differentiating tags from the WHERE clause.

If you have challenges with 0.9 and merging three series as mentioned in your earlier comment, please open a new issue.