Canonical Juju

  1. Series 2.4
  2. Bug #1793245
  3. Comment #0

Comment 0 for bug 1793245

Revision history for this message
Haw Loeung (hloeung) wrote : Juju agents DoS'ing the server

Hi,

This has happened a couple of times now. I know that there's an open bugs for lots of MongoDB connections but not sure if there's one for agents DoS'ing the controller.

Today, we've had the Juju machine agent OOM killed on one of the controllers. This caused a storm where a bunch of agents were all connecting to a single controller (which happens to also be the MongoDB primary but I don't think that's related).

Controllers are:

| ubuntu/0 10.25.2.109
| ubuntu/1 10.25.2.111
| ubuntu/2 10.25.2.110

The one that was getting hammered was ubuntu/1. The work-around was the firewall off client connections on ubuntu/1.

I'm not sure what magic happens and how clients pick which controller it should talk to. Does it try to connect to all 3 and completing the handshake to the one that responds first? Or does it pick from a list given hitting the first?

For the Juju 2 controller environment, .local/share/juju/controllers.yaml looks like this:

| api-endpoints: ['10.25.2.111:17070', '10.25.2.110:17070', '10.25.2.109:17070']