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4 points by thaddeus 4297 days ago | link | parent

Hmmm it's been a really long time since I looked at the code, but I would try two things.

1. Enter this-site* at the prompt to confirm the change took place.

2. Abort the session, I.e such that the arc prompt is killed. Then goto the webpage and make sure its no longer running news (just to confirm the abort occurred and/or is not somehow running a past instance), then reload arc again.



2 points by akkartik 4297 days ago | link

Yeah these are good suggestions. The "address already in use" error suggests that you might have multiple copies of arc running, so that you're making changes to the wrong copy. Use the commands 'ps' and 'kill' to look for the other copies and stop them.

http://stackoverflow.com/questions/3510673/find-and-kill-a-p...

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2 points by pier0 4297 days ago | link

I used the command ps aux | grep 'news.arc' and it returned only one copy running, but I suspect that's not right.

And your comment about multiple copies also got me thinking that from the main Arc directory to go into the Arc prompt maybe I shouldn't have been using $ mzscheme -f as.scm

Was I supposed to use that just once to run news.arc for the first time?

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3 points by akkartik 4297 days ago | link

No, you want to run:

  $ ps aux |grep mzscheme
ps doesn't know about news.arc, that's just one of the files loaded by mzscheme.

I didn't understand the second and third paragraphs. Can you tell me more about what version of arc you downloaded and how you're running it?

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2 points by pier0 4296 days ago | link

I did as you suggested and found a second process running, Then I run this

kill $(ps aux | grep '[m]zscheme' | awk '{print $2}')

and it killed one. After it was just a matter of starting-restating Arc with the changes in news.arc.

And next is the logo. Thanks for your precious advice.

PS In the previous post I was starting to doubt that I'm not supposed to use mzscheme -f as.scm as a command to get to the Arc prompt

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2 points by akkartik 4296 days ago | link

Great!

Out of curiosity, how do you stop the server once you start it?

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2 points by pier0 4293 days ago | link

I eventually connected the problem with the multiple copies of Arc running with having a detached screen, so I stopped that and closed the terminal.

After doing so the news site was down, which I believe is what Thaddeus was recommending to happen.

Then I had to restart it and detach the screen and start the process again.

It is not ideal, but I think it works.

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2 points by thaddeus 4292 days ago | link

Assuming you're using 'GNU screen' you also have the option to re-attach to an existing session using the 'screen -r' command. Using 'screen -ls' will list out all the sessions should you not be sure, or have more than one.

That aside, most developers will do development changes on a local machine where they need not attach/reattach and this way you wouldn't need to troubleshoot your code and the host environment at the same time.

Then you create a stable deployment process. eg. Backup the old code, drop in the new code, re-attach to the existing session and either load your changes or restart the program if you're ok with some nominal downtime.

Hope that helps.

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2 points by pier0 4296 days ago | link

I couldn't understand what you meant by "make sure its no longer running news" but now I know.

Basically I got a bad gateway error and the web page was no longer accessible until I reloaded news.arc

  arc> (load "news.arc")
  arc> (nsv)
Thanks thaddeus

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3 points by thaddeus 4294 days ago | link

No problemo and yeah, in retrospect, I could have chosen better terminology and been much more descriptive, but that's one of the things you will enjoy about the arc forum... You just keep asking and, generally speaking, people are very helpful. After all, I learned how to program by just doing what you are, running the news app, reading the arc code and relying on this forum for help along the way.

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