Mailing List Message #390
From: Ramsey Gurley <>
Subject: Re: [WO-DEV] Re: Non instance found but Monitor shows it as being up and running
Date: Thu, 17 Nov 2022 23:11:53 +0000
To: WebObjects & WOnder Development <>
It sounds like your instance is running, but not responding. Which could be any number of things causing that. Usually, when this happens to me, it is often a deadlock and I see a 'no statistics available' message for that instance on the java monitor application page. I have my instances configured to allow me to jconsole into them and search for deadlocks. But it could be something else, like the shared db connection being tied up for too long while you're waiting on a page that needs data from the db. In that case, you could play with the connect timeout settings in monitor and extend it so that you get a page if you are willing to wait long enough. I look for this by logging long queries to the application log. When I see those start to happen, I try to do what can be done to speed up the queries.

Just knowing you're getting a 'no instance available' doesn't tell me much though.

From: WebObjects & WOnder Development on behalf of Markus Ruggiero (rucotec)
Sent: Thursday, November 17, 2022 8:45 PM
To: WebObjects & WOnder Development
Subject: [WO-DEV] Re: Non instance found but Monitor shows it as being up and running

No one?

Is there documentation for REST calls to wotaskd and/or JavaMonitor? I haven’t found anything, might have been looking in the wrong place 🙃


> On 15 Nov 2022, at 16:20, Markus Ruggiero (rucotec) <> wrote:
> This is a weird one.
> We have a WOApp deployed on Ubuntu 20.04.5 LTS on a cloud server. App is classically controlled by JavaMonitor and instance (currently only one) is scheduled for restart every day at 5am. Once in a while the first user in the morning is greeted by “no instance found”, but checking with JavaMonitor everything looks good and there are not deaths reported! Manually restarting the instance clears things up. It seems that sometimes the instance does not come up fully or the connection with WOAdaptor to Apache breaks. Anyone having had similar issues? We are running a fairly up-to-date Apache (Server version: Apache/2.4.41 (Ubuntu) Server built:   2022-06-14T13:30:55). WOAdaptor is the one built by Maik (thanks a lot for this).
> Another weird thing is that we have various other applications running on the same and on other similarly set up servers, none of them having any issues. Any idea on that?
> Is there a way to externally trigger Monitor or WOtaskd to restart an instance? Does the REST interface support this and how would I call it with e.g. curl? I could then create my own heartbeat script testing and restarting instances through Apache.
> Thanks for any help
> ---markus---

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