Add a client InfluxDBClusterClient to handle a cluster of InfluxDB servers

[cannium]

No description provided.

[cannium]

I'll try to figure out how to properly test the class. But before that I must fix my InfluxDB cluster where I seems to hit bugs.

[gst]

What would be incredible is a(some) test case(s), against a real cluster, where you "kill" (in a way or another) some of the cluster nodes and you assert that queries are always executed (and get the correct answer) despite some of the nodes being killed/shutdown..

I have to agree/say that it's not necessarily easy to get that.. Doing it with mocks could be quite more easy to get working.. to be seen..

[cannium]

Modified code pushed, tests and docs comming

[cannium]

Seems the failure isn't caused by this patch set, how can I trigger a retest?

[aviau]

You can't. I just did!

[aviau]

I intend to review this soon, sorry for the delay!

[gst]

You could/should also "assert the whole try/except block" with :

with self.assertRaises(InfluxDBServerError) as ctx:
    cluster.query('Fail')

?
EDIT: the as ctx isn't required/necessary as you don't assert anything specifically on the exception instance itself.

[cannium]

done

[aviau]

Looks great, but my one issue with this is that I wonder how other clients will be able to use it.

For example the DataFrameClient and the SeriesHelper.

Would there be an acceptable way of including this in the InfluxDBClient?

[cannium]

By setting (client_base_class=xxx)[https://github.com//pull/148/files#diff-6f7b00b2898af5d67cc2a1ff0346c331R485] I suppose?

[aviau]

Oh, I had overlooked! Makes sense!

However, other clients may need other things in the init.

Also, maybe we should use from_DSN?

[cannium]

Seems current from_DSN code in current code can not handle connection strings like influxdb://username:password@host1:port1,username:password@host2:port2,username:password@host3:port3/database_name, as in some other db.
What I'm thinking about is to create a function like create_new_client, if the connection string given includes a single server, returns an instance of InfluxDBClient, otherwise return an instance of InfluxDBClusterClient. What do you think?

[aviau]

@cannium Sorry for the delay.

It looks like this is ready to be merged! Can I proceed? :)

[cannium]

Sure, go ahead

[aviau]

Thank you for your contribution!