Guacamole Database Schema - disconnected sessions

[Adrian Owen <ad...@eesm.com>]

In our automated Guacamole solution we currently enable VIDEO on every connection and monitor for no lock on the video stream file. We allow for .1, .2 etc.

But this puts overhead on Guacamole, disk certainly and risk of bottleneck.

I would prefer to make a MYSQL call to the database, and enquire on the state of connections.

Is there a documentation on the Schema, or failing that, which MYSQL tables should I select to see active and disconnected sessions?

Thanks, Adrian

Re: Guacamole Database Schema - disconnected sessions

[Nick Couchman <vn...@apache.org>]

On Tue, Feb 25, 2020 at 12:45 PM Adrian Owen <ad...@eesm.com> wrote:

> Hi Nick,
>
>
>
> --Connection history is stored persistently, but these entries are made
> after the connection is closed
>
>
>
> So new entry in connection history table means a connection has just
> closed.
>
>
>
> That’s all we need to know,   If connections always result in history
> entry after termination, this is solution?
>
>
>

This is how Guacamole behaves today, but I'm not sure I'd consider that a
reliable form of doing any sort of contention locking.  Also, that behavior
may change in the future - there are a couple of issues in JIRA for
improving HA support in Guacamole, and some of these may lead to changes in
how that behaves.  That's not certain - nothing has been decided at this
point - I'm just not sure I would rely upon that behavior for any sort of
contention locking.

-Nick

RE: Guacamole Database Schema - disconnected sessions

[Adrian Owen <ad...@eesm.com>]

Hi Nick,

--Connection history is stored persistently, but these entries are made after the connection is closed

So new entry in connection history table means a connection has just closed.

That’s all we need to know,   If connections always result in history entry after termination, this is solution?


Thanks, Adrian

From: Nick Couchman [mailto:vnick@apache.org]
Sent: 25 February 2020 17:31
To: user@guacamole.apache.org
Subject: Re: Guacamole Database Schema - disconnected sessions

On Tue, Feb 25, 2020 at 8:54 AM Adrian Owen <ad...@eesm.com>> wrote:

In our automated Guacamole solution we currently enable VIDEO on every connection and monitor for no lock on the video stream file. We allow for .1, .2 etc.

But this puts overhead on Guacamole, disk certainly and risk of bottleneck.

I would prefer to make a MYSQL call to the database, and enquire on the state of connections.

Is there a documentation on the Schema, or failing that, which MYSQL tables should I select to see active and disconnected sessions?


Currently active session tracking is only done in memory - it is not stored anywhere persistently.  Connection history is stored persistently, but these entries are made after the connection is closed, so the database cannot be relied upon to contain a record of what sessions are active.  To change this behavior will require some work in the code - it's not something that can be enabled/disabled.

-Nick

Re: Guacamole Database Schema - disconnected sessions

[Nick Couchman <vn...@apache.org>]

On Tue, Feb 25, 2020 at 8:54 AM Adrian Owen <ad...@eesm.com> wrote:

>
>
> In our automated Guacamole solution we currently enable VIDEO on every
> connection and monitor for no lock on the video stream file. We allow for
> .1, .2 etc.
>
>
>
> But this puts overhead on Guacamole, disk certainly and risk of bottleneck.
>
>
>
> I would prefer to make a MYSQL call to the database, and enquire on the
> state of connections.
>
>
>
> Is there a documentation on the Schema, or failing that, which MYSQL
> tables should I select to see active and disconnected sessions?
>
>
>

Currently active session tracking is only done in memory - it is not stored
anywhere persistently.  Connection history is stored persistently, but
these entries are made after the connection is closed, so the database
cannot be relied upon to contain a record of what sessions are active.  To
change this behavior will require some work in the code - it's not
something that can be enabled/disabled.

-Nick

>