There's 2 possibilities:
1) Software failure, and nobody's noticed yet.
2) This is the long anticipated/dreaded hardware failure, and the "maintenance" message is just the standard fall back message. And again, possibly no one has noticed yet, to change it to a "bad news" message.

I'm guessing the latter.

QCN has been down for quite a few days now... Any updates ?

It also seems QCN no longer accepts my e-mail address when I try to log into: http://qcn.emsc-csem.org/sensor/login_form.php

Perhaps related to the outage?

QCN is back up.
It was just a long maintenance break after all.

However, NO credits for a while.

There's a news item on the message boards.

Message from Carl regarding QCN:

It should be up now - I took it down to do one final update for BOINC server software, and created a million workunits which should last two years if the servers stay up.
The project is now on "autopilot" as there is no funding or personnel left. It's possible CalTech will apply for funding & hire staff in the future.
I'm sorry about the credits but since BOINC has no automatic function for 'non-compute intensive" (NCI) applications such as QCN - running the credit script means that the entire result & workunit tables (which are huge) have to be kept; and with our old hardware there's no way the project can even go a few months without these huge tables pruned and archived.

Have not been able to get BoincStats.com to load for around 6 hours now...

When attempting to load the web page the CloudFlare servers replies with:
Error 522 Ray ID: 250e771952982647 • 2015-12-07 07:20:15 UTC
Connection timed out
If you're the owner of this website:
Contact your hosting provider letting them know your web server is not completing requests. An Error 522 means that the request was able to connect to your web server, but that the request didn't finish. The most likely cause is that something on your server is hogging resources.

Confirmed it's down for the count: It's not just you! http://boincstats.com looks down from here

BoincStats.com was down due to a power failure and is back up...
News Item at BoincStats from Willy:

There was a power failure at the DC in one of the two mains power supplies and without power the servers don't do so well.

We do not have a Automatic transfer switch (ATS) to switch between the two power supplies so I had to drive up here to get things going again.

We had about a twelve hour downtime.

Addendum: I ordered an ATS to prevent this problem in the future.

and this addendum:

There will be another downtime in a couple of days when the ATS is placed.

Announcement by the CPDN project team:

We will be taking the project offline tomorrow (Wednesday 9th December) from 10am (UK time) in order to take a snapshot of the database. This is part of the process of the re-configuration of a slave database machine. Once this snapshot process has completed we will bring the project back online again, we anticipate that this process will take a minimum of 24 hours to complete. We apologise in advance for any inconvenience.

Outage due to primary disk failure
Due to the primary disk finally failing completely there was about 8h of downtime for the project today. For some reason the disk failure brouht the server down even though we are running from the backup disk since July.

The failed disk has been replaced now and the project is slowly catching up with work distribution. Apologies for the outage!

https://moowrap.net/

Announcement by the CPDN project team:

We will be taking the project offline tomorrow (Wednesday 9th December) from 10am (UK time) in order to take a snapshot of the database. This is part of the process of the re-configuration of a slave database machine. Once this snapshot process has completed we will bring the project back online again, we anticipate that this process will take a minimum of 24 hours to complete. We apologise in advance for any inconvenience.

The planned work has been completed and CPDN is now back online.

The Collatz database crash sequence seems to be on the order of -- expect it to happen and plan for it with available alternative projects.

The crash happens when MySQL goes unresponsive. There is no solid way to anticipate when that will happen and thus no means to pre-empt an unplanned crash via a planned shutdows (or scripted shut down and restart).

The database crash happens after the server has been running for somewhere between 20 and 48 hours.

When it crashes, the recovery cycle takes between 4 hours and 24 hours, depending on a number of variables.

Until the length of the work units is significantly increased (something that is being worked on)< the workload on the server (one of the apparent variables regarding the semi-regular crashes) will continue to result in the current frequency of the crashes.

The hope is that with a shift to the longer work units, the server load will be abated and the frequency of crashes reduced from the current 2 to 3 times a week to less than once a week.

Cosmology@Home is back up.

Marius wrote:

We were down for the last ~24hrs due to some networking issues which are now fixed. We apologize for the inconvenience.

Constellation appears to be down.

POEM site currently can't be accessed at all

I am able to access the POEM site.

NFS@home has been going up and down for the last few days.

It looks like NFS@home is fully down for today.

NFS@home is up. It turns out that it was moving to another data center, and I had missed the announcement that it was moving.

Collatz is down as of Friday, Jan 15th

Collatz is back up as of Sunday, Jan 17th

---