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Flexible server monitoring

Introducing Simon 5!

Simon version 5 is now available. It is a massive update, introducing a much-requested feature: syncing the Simon data between multiple Macs, plus a Simon Status service, a Link Checker filter, improved Find filter, iMessage and Speak Error notifiers, a new app icon, and much more.

Important: please note that Simon 5 requires a minimum of macOS 10.12 (Sierra), and is a paid upgrade from Simon 4. Purchasers since September 1, 2020 automatically get a version 5 license (that also works in previous versions).

Read the Simon What's New page for details.

Test for Simon app health?

Is there an easy way to test for the health of the Simon app, to ensure that it's not crashed, quit accidentally or hung?

Some apps (like Keep It Up) have HTTP interfaces that display a status or other information, some have other open ports that return certain text that can be checked there something similar in Simon that I can use to be sure that the app is open, is working properly and is not hung?


David Sinclair's picture

Re: Test for Simon app health?

You could use another copy of Simon (on another machine) to check for Simon via SSH and ps.

Or if manually observing, you could look at the dates and times on Simon's HTML reports. You could automatically look at the creation date of these files, too.

A future version of Simon will split the scheduling etc functionality into multiple processes, which will include automatic checks that it remains running.

JohnDCCIU's picture

SSH and ps doesn't seem like

SSH and ps doesn't seem like it would test reliably for a hung app (like I had this weekend). ps would still show it running, even though it's hung.

I guess testing for dates/times on Simon's HTML reports would do the trick, but that's pretty painful compared to checking for a reply from an open port.

Would you consider building in a "health check" in Simon, where it would provide basic information on a user-selected port via HTTP? Then we could monitor the app directly, knowing that if it doesn't reply with the correct response on that port, something is awry.

David Sinclair's picture

Re: SSH and ps doesn't seem like

It's a good idea. I am considering adding a port-based check to ensure it's running in a future version anyway, so making that available to users could be beneficial. I'll make a note of that suggestion. Thanks!

roberto's picture

health check for

hey there

just wwwondered what's the latest regarding this thread?

- whilst it's (currently) a little over my head it looks/sound very useful :-)



David Sinclair's picture

Re: health check for

There is a "Pulse" service that is guaranteed to always change, so can be used to send out notifications every time it is checked. If you use that, and don't receive a notification, you know Simon has stopped.

I still plan to split the app into multiple components, as discussed. That'll be coming next year (was going to be this year, but I got distracted with iPhone apps).