Solr, Tomcat and HTTP/1.1 505 HTTP Version Not Supported

During today’s hacking aboot I came across the above error from our Solr query library. The error indicates that some part of Tomcat was unable to parse the “GET / HTTP/1.1” string – where it is unable to determine the “HTTP/1.1” part. A problem like this could be introduced by having a space in the query string (and it not being escaped properly), so that the request would have been for “GET /?a=b c HTTP/1.1”. After running through both the working and non-working query through ngrep and wireshark, this did however not seem to be the problem. My spaces were properly escaped using plus signs (GET /?a=b+c HTTP/1.1).

There does however seem to be a problem (at least with our version of Tomcat – 6.0.20) which results in the +-s being resolved before the request is handed off to the code that attempts to parse the header, so even though it is properly escaped using “+”, it still barfs.

The solution:

Use %20 to escape spaces instead of + signs; simply adding str_replace(” “, “%20”, ..); in our query layer solved the problem.

Transparent Remapping of / For Struts Actions

I’ve been trying to find a solution to this issue for a couple of hours: We have several struts actions in our Java-based webapp, all neatly mapped through different .do action handlers. I wanted to switch our handling of the root / index URL ( from being a static redirect to the actual action to instead present the content right there, without the useless redirect. This apparently proved to be harder than I thought; after searching a lot through Google, reading through mailing lists and the official documentation, it seems that there is no way to specify an action to handle these requests by default in struts. There may be one, but I could not for the life of ${deity} find it.

As simply doing it in Struts were out of the question, I turned to an old friend of mine, the ever so helpful mod_rewrite. mod_rewrite is capable of rewriting URLs internally in Apache before they get handled at other levels. The problem was that mod_jk seemed to grab the request before the replacements were made, but a few resources pointed me in the correct direction:

After a bit of debugging with the rewritelog, everything came together. This is how it ended up:

       	RewriteEngine On
       	RewriteLog /tmp/rewrite.log
       	RewriteLogLevel 3
       	RewriteRule ^/?$ /destinationfile [PT,NE]

The RewriteLog say that we should log the rewrite progress to /tmp/rewrite.log, and RewriteLogLevel say that we should log at the most detailed format. Use 0, 1, 2 for less debugging information. Remember to comment out these lines when things work. DO NOT use the RewriteLog when not actually debugging the rewrites.

Solving UTF-8 Problems With Solr and Tomcat

Came across an issue with searching for UTF-8 characters in Solr today; the search worked just as it should (probably since we’re using a phonetic field to search), but our facets and limitations didn’t work as they should. This happened as soon as we had a value with an UTF-8 character (> 127 in ascii value), in our case the norwegian letters Æ, Ø or Å.

The solution was presented by Charlie Jackson at the Solr-user mailing list and is quite simply to add URIEncoding="UTF-8" to the appropriate connector in the Tomcat server.xml file. This is also documented on the Solr on Tomcat page in the Solr Wiki .