SolrNet lowercases Solr field names on query string, causes Solr 1.4 to fail

This is a strange bug that we started seeing about a year ago. At first, I only occasionally noticed it on my dev machine, but now it's been starting to appear in production, which is problematic.

We use Ubuntu (11.04), and Mono 2.6.7 in production (I can also repro with Mono 2.10.x), ins开发者_Go百科ide apache, using mod_mono.

Basically, sometimes (very hard to reproduce), when apache starts the application, SolrNet decides to lower case the entire URL it transmits to the solr server. If the application is in this state, it stays this way until it is restarted (and occasionally requires a couple of restarts to clear up.) We might go for 20 - 50 or more restarts without seeing this problem come up. or sometimes it will happen every 2 or 3.

A good url looks like this:

INFO: [] webapp=/solr path=/select params={sort=Creative.PromotionalScore+desc&start=0&q=*:*&?=&qt=standard&fq={!tag%3DCreative.GalleryReviewStatus}Creative.GalleryReviewStatus:Approved&fq={!tag%3DCreative.SectionIncludedTarget}Creative.SectionIncludedTarget:220358+OR+(NOT+Creative.SectionIncludedTarget:[*+TO+*]+*:*)&fq={!tag%3DActive}Active:true&fq={!tag%3DCreative.ShowInGallery}Creative.ShowInGallery:true&fq={!tag%3DCreative.Size}Creative.Size:"Rectangle"&fq={!tag%3DRecordType}RecordType:FiveToOne.Gallery.Rmx.Creative&rows=12} 

A bad url looks like this:

http://solrServer:8080/solr/select?qt=standard&fq=%7b!tag%3dcreative.galleryreviewstatus%7dcreative.galleryreviewstatus%3aapproved&fq=%7b!tag%3dcreative.sectionincludedtarget%7dcreative.sectionincludedtarget%3a306433+or+(not+creative.sectionincludedtarget%3a%5b*+to+*%5d+*%3a*)&fq=%7b!tag%3dactive%7dactive%3atrue&fq=%7b!tag%3dcreative.showingallery%7dcreative.showingallery%3atrue&fq=%7b!tag%3dcreative.size%7dcreative.size%3a%22rectangle%22&fq=%7b!tag%3drecordtype%7drecordtype%3afivetoone.gallery.rmx.creative&sort=creative.promotionalscore+desc&rows=18&start=0&q=*%3a*&?

(first, I apologize, these two URLs are extracted from different stages of the pipe, all I have access to at the moment.)

When the bad url is submitted, Solr throws a fatal exception, complaining of an unknown field:

HTTP Status 400 - can not sort on undefined field: creative.promotionalscore

type Status report

message can not sort on undefined field: creative.promotionalscore

description The request sent by the client was syntactically incorrect (can not sort on undefined field: creative.promotionalscore).

Having used Solr and SolrNet in production for four years now, all I can say is that I've never seen this on .NET, so I'm guessing it's a bug in Mono.

In order to pinpoint where exactly the URL is becoming lowercase, I'd put several logging points, for example here, here, and here.

After this logging is in place, once the bug occurs, the log should be analyzed, logging should be probably refined, etc, until the exact source of the bug is located.

Hopefully then the bug can be reproduced, reported, fixed, etc.