6 Troubleshooting and Tips

6.1 How do I use Apache with the PLT Web Server?

You may want to put Apache in front of your PLT Web Server application. Apache can rewrite and proxy requests for a private (or public) PLT Web Server:

RewriteRule ^(.*)$ http://localhost:8080/$1 [P]

The first argument to RewriteRule is a match pattern. The second is how to rewrite the URL. The [P] flag instructs Apache to proxy the request. If you do not include this, Apache will return an HTTP Redirect response and the client should make a second request.

See Apache’s documentation for more details on RewriteRule.

6.2 Can the server create a PID file?

The server has no option for this, but you can add it very easily. There’s two techniques.

Using exec will reuse the same process, and therefore, the PID file will be accurate.

Second, if you want to make your own Scheme start-up script, you can write:

(require mzlib/os)

(with-output-to-file your-pid-file (lambda () (write (getpid))))

(start-server)

6.3 How do I set up the server to use HTTPS?

This requires an SSL certificate and private key. This is very platform specific, but we will provide the details for using OpenSSL on UNIX:

  openssl genrsa -des3 -out private-key.pem 1024

This will generate a new private key, but it will have a passphrase on it. You can remove this via:

Now, we generate a self-signed certificate:

  openssl req -new -x509 -nodes -sha1 -days 365 -key private-key.pem > server-cert.pem

(Each certificate authority has different instructions for generating certificate signing requests.)

We can now start the server with:

  plt-web-server --ssl

The Web Server will start on port 443 (which can be overridden with the -p option) using the "private-key.pem" and "server-cert.pem" we’ve created.

6.4 How do I limit the number of requests serviced at once by the Web Server?

Refer to Limiting Requests.