# Road map of ferret **URL:** \ **Category:** Ferret\ **Created:** [August 19, 2008, 9:29pm UTC](https://www.ruby-forum.com/t/road-map-of-ferret/146298 "2008-08-19T21:29:52Z")\ **Posts on this page:** 6\ **Page:** 2
**Author:** ![Fernando\_Parisotto](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/90ced4/32.png) [@Fernando\_Parisotto](https://www.ruby-forum.com/u/Fernando_Parisotto)\ **Post date:** [August 28, 2008, 5:34pm UTC](https://www.ruby-forum.com/t/road-map-of-ferret/146298/21 "2008-08-28T17:34:36Z")
That is one awesome rebuttal, Jens. I read that forum topic below, and while I have a great respect for Ezra (from his fine book Deploying Rails Applications), I must say I disagree with him with respect to Ferret/AAF combination. We run Ferret/AAF as a DRb server in production and on our staging servers and I’ve never seen a Ferret segfault. That said, we’re not high search load like Google, but even when hit with heavy load testing, I haven’t experienced a Ferret segfault, nor corrupt indexes. Now, corrupt indexes in development is another issue. In development, you are not running a DRb server. Each mongrel is hitting the index directly. You typically have only one mongrel running in development. But if you open an interactive script/console session, and play with your models side-by-side a running mongrel, you WILL corrupt your Ferret index. That’s because both the mongrel and the script/console will be writers to the same index, something that Ferret doesn’t support. Heck, running a rake db:migrate along side a running mongrel will cause index corruption, for the same reason: multiple writers. I’m wondering if that’s why so many people experience Ferret indexing problems in development? It’s not immediately obvious that you’re in a multiple writer scenario some times. For now, I’m sticking with the Ferret/AAF combination until one or the other falls over completely. Sheldon M. Developer [http://ideas.veer.com](http://ideas.veer.com) ---
**Author:** ![Fernando\_Parisotto](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/90ced4/32.png) [@Fernando\_Parisotto](https://www.ruby-forum.com/u/Fernando_Parisotto)\ **Post date:** [August 28, 2008, 7:31pm UTC](https://www.ruby-forum.com/t/road-map-of-ferret/146298/22 "2008-08-28T19:31:48Z")
On 28.08.2008, at 17:17, Erik H. wrote: > If you’re talking about custom analyzers being in Ruby, more on that > below. It’s not only custom analyzers, but the fact that acts\_as\_ferret’s DRb runs with the full Rails application loaded, so i.e. to bulk index a number of records aaf just hands the server the ids and class name of the records to index, and the server does the rest. It’s debatable if one approach is better than the other, in terms of index server load it might even be better to do as much as possible on the client side, but still it’s a much tighter coupling than you get with the application agnostic interfaces of solr or stellr. I must admit that I have a hard time to come up with another example besides my synonym/thesaurus analysis stuff where this might useful, but I think there are more use cases where such a tight integration might come in handy. > > It’s an independent server indexing whatever you throw over the > > fence via http+xml. > > Solr can index CSV as well now a relational database directly (with > the new DataImportHandler). > > It also responds with Ruby hash structure (just add &wt=ruby to the > URLs, or use solr-ruby which does that automatically and hides all > server communication from you anyway). Yeah, I know, but anyway there is a strict line between your application and Solr, which doesn’t know a thing about the application using it. > > How to use a custom analyzer with solr? You have to code it in Java > > (or you do your analysis before feeding the data into java land, > > which I wouldn’t consider good app design). > > Most users would not need to write a custom analyzer. Many of the > built-in ones are quite configurable. Yes, Solr does require schema > configuration via an XML file, but there have been acts\_as\_solr > variants (good and bad thing about this git craze) that generate > that for you automatically from an AR model. Glad you mentioned this 😉 I don’t want to configure an analyzer via xml when I can throw my own together with 4 or 5 lines of easy to read ruby code. Same for index structure. Philosophical mismatch between the Java and Ruby worlds I think 🙂 > > But even if you do that then you have > > a) half a java project (I don’t want that) > > That’s totally fair, and really the primary compelling reason for a > Ferret over Solr for pure Ruby/Rails projects. I dig that. > > But isn’t Ferret is like 60k lines of C code too?! true, but I don’t have to compile that every time I deploy my app… > > and b) no way to use your existing rails classes in that custom > > analyzer (I _have_ analyzers using rails models to retrieve > > synonyms and narrower terms for thesaurus based query expansion) > > You could leverage client-side query expansion with Solr… just > take the users query, massage it, and send whatever query you like > to Solr. Solr also has synonym and stop word capability too. yeah, I could do that. But that’s moving analysis stuff into my application, which is quite contrary to the purpose of analyzers - encapsulate this logic and make it pluggable into the search engine library. So less style points for this solution… > However, there is also no reason (and I have this on my copious-free- > time-TOOD-list) that JRuby couldn’t be used behind the scenes of a > Solr analyzer/tokenizer/filter or even request handler… and do all > the cool Ruby stuff you like right there. Heck, you could even send > the Ruby code over to Solr to execute there if you like 😉 that sounds sexy 😉 > Just using Solr and fixing up acts\_as\_solr to meet your needs (if it > doesn’t) would be even easier than all that 🙂 Solr really is a > better starting point than Lucene directly, for caching, > scalability, replication, faceting, etc. Depends on whether you need these features or not. From my experience, lots of projects don’t need these things anyway, because they’re running on a single host and nearly every other part of the application is slower than search… Maybe it’s because I’m quite involved with the topic and am familiar with lucene’s API, but to me Solr looks like an additional layer of abstraction and complexity which I only want to have when it really gives me a feature I need. Plus the last time I checked Lucene didn’t need xml configuration files 😉 In development environments and especially when it comes to automated tests / CI it’s also quite comfortable not having to run a separate server but using the short cut directly to the index, which isn’t possible with Solr. > I’d be curious to see scalability comparisons between Ferret and > Solr - or perhaps more properly between Stellr and Solr - as it > boils down to number of documents, queries per second, and faceting > and highlighting speed. I’m betting on Solr myself (by being so > into it and basing my professional life on it). This would be interesting, but I wouldn’t be that disappointed with Stellr ending up second given the little amount of time I’ve spent building it so far. Just out of curiosity, do you have some kind of performance testing suite for Solr which I could throw at Stellr? Cheers, Jens – Jens Krämer Finkenlust 14, 06449 Aschersleben, Germany VAT Id DE251962952 [http://www.jkraemer.net/](http://www.jkraemer.net/) - Blog [http://www.omdb.org/](http://www.omdb.org/) - The new free film database ---
**Author:** ![Fernando\_Parisotto](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/90ced4/32.png) [@Fernando\_Parisotto](https://www.ruby-forum.com/u/Fernando_Parisotto)\ **Post date:** [August 28, 2008, 8:11pm UTC](https://www.ruby-forum.com/t/road-map-of-ferret/146298/23 "2008-08-28T20:11:05Z")
On Aug 28, 2008, at 10:10 AM, Jens Krämer wrote: > With Ferret I can use custom tokenizers to inject additional terms > at the same offset (i.e., synonyms), is there another way to achieve > that with KinoSearch? Synonym support isn’t part of the public API right now, but since the basic principle is the same in KinoSearch as it is in Ferret and Lucene, it shouldn’t be hard to add. I don’t think we’d do this by extending Tokenizer; I think we’d want SynonymFilter/SynonymMap classes akin to the ones provided by Solr. Marvin H. Rectangular Research [http://www.rectangular.com/](http://www.rectangular.com/) ---
**Author:** ![Fernando\_Parisotto](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/90ced4/32.png) [@Fernando\_Parisotto](https://www.ruby-forum.com/u/Fernando_Parisotto)\ **Post date:** [August 28, 2008, 8:08pm UTC](https://www.ruby-forum.com/t/road-map-of-ferret/146298/24 "2008-08-28T20:08:09Z")
On Aug 28, 2008, at 1:02 PM, Jens K. wrote: > > What advantage does Ferret have in terms of ActiveRecord > > integration that Solr wouldn’t have? > > > > If you’re talking about custom analyzers being in Ruby, more on > > that below. > > It’s not only custom analyzers, but the fact that acts\_as\_ferret’s > DRb runs with the full Rails application loaded, so i.e. to bulk > index a number of records aaf just hands the server the ids and > class name of the records to index, and the server does the rest. Gotcha. Meaning the search server is pulling from the DB directly. That’s what the DataImportHandler in Solr does as well. It’d be a simple single HTTP request to Solr (once the DB stuff is configured, of course) to have it do full or incremental DB indexing. > Glad you mentioned this 😉 I don’t want to configure an analyzer via > xml when I can throw my own together with 4 or 5 lines of easy to > read ruby code. Same for index structure. Philosophical mismatch > between the Java and Ruby worlds I think 🙂 Don’t get me wrong… I’m a Ruby fanatic myself! XML makes me ill, generally speaking (it has its uses, but for configuration it is just plain wrong). For using the built-in tokenizer/filters, a smarter acts\_as\_solr could generate the right config based on a model specifying parameters for analysis. > > > But even if you do that then you have > > > a) half a java project (I don’t want that) > > > > That’s totally fair, and really the primary compelling reason for a > > Ferret over Solr for pure Ruby/Rails projects. I dig that. > > > > But isn’t Ferret is like 60k lines of C code too?! > > true, but I don’t have to compile that every time I deploy my app… My point was that Ferret isn’t just Ruby, just a counter point to your “half a java project”. No one has to recompile Solr either. > encapsulate this logic and make it pluggable into the search engine > library. So less style points for this solution… I was just saying 🙂 It’s debatable exactly where in the client- server spectrum synonym expansion belongs… and it really depends on the needs of the project. Nothing wrong with a client doing some user input massaging before a query hits the search server. > > However, there is also no reason (and I have this on my copious- > > free-time-TOOD-list) that JRuby couldn’t be used behind the scenes > > of a Solr analyzer/tokenizer/filter or even request handler… and > > do all the cool Ruby stuff you like right there. Heck, you could > > even send the Ruby code over to Solr to execute there if you like 😉 > > that sounds sexy 😉 Should be fairly trivial to wire JRuby in. The DataImportHandler already has scripting language support for data transformation: \<[DataImportHandler - Solr - Apache Software Foundation](http://wiki.apache.org/solr/DataImportHandler#head-27fcc2794bd71f7d727104ffc6b99e194bdb6ff9) > (shield your eyes from the XML wrapping it!), so I believe JRuby > should already work in that context. This is sort of like the Mapper > stuff I built into solr-ruby, transforming data from domain to search > engine “documents”. > > > > Solr looks like an additional layer of abstraction and complexity > which I only want to have when it really gives me a feature I need. > Plus the last time I checked Lucene didn’t need xml configuration > files 😉 I hear ya about the XML config files. And always to be fair to Solr here, you really only need to set things up from a basic example configuration that covers most scenarios already - so it really isn’t necessary to even touch XML config except for tweaking little things. But Solr’s advantages over just Lucene are built out of experiences that most Lucene projects eventually build anyway. Caching - really important for faceting, which is a need that every project I touch these days needs. Replication - really really important for scalability of massive querying load. It’s really not such a big chunk over Lucene to bite off… and in almost all respects it is even simpler to use Solr than Lucene anyway. > In development environments and especially when it comes to > automated tests / CI it’s also quite comfortable not having to run a > separate server but using the short cut directly to the index, which > isn’t possible with Solr. Not true. Solr can work embedded. There is a base SolrServer abstraction, with an implementation that runs embedded (inside the same JVM) versus over HTTP. Exactly the same interface for both operations, using a very simple API (SolrJ, much like Lucene’s basic API actually). > > I’d be curious to see scalability comparisons between Ferret and > > Solr - or perhaps more properly between Stellr and Solr - as it > > boils down to number of documents, queries per second, and faceting > > and highlighting speed. I’m betting on Solr myself (by being so > > into it and basing my professional life on it). > > This would be interesting, but I wouldn’t be that disappointed with > Stellr ending up second given the little amount of time I’ve spent > building it so far. Just out of curiosity, do you have some kind of > performance testing suite for Solr which I could throw at Stellr? No, I don’t have those kinds of tests myself. While I can speak to Solr’s performance based on what I hear from our clients and the reports in the mailing lists, I don’t consider myself a performance savvy person myself. I’m curious - what are the numbers of documents being put into Ferret indexes out there? millions? hundreds of millions? billions? And are folks doing faceting? Does Ferret have faceting support? Erik ---
**Author:** ![Fernando\_Parisotto](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/90ced4/32.png) [@Fernando\_Parisotto](https://www.ruby-forum.com/u/Fernando_Parisotto)\ **Post date:** [August 28, 2008, 9:06pm UTC](https://www.ruby-forum.com/t/road-map-of-ferret/146298/25 "2008-08-28T21:06:14Z")
On 28.08.2008, at 20:03, Erik H. wrote: > > index a number of records aaf just hands the server the ids and > > class name of the records to index, and the server does the rest. > > Gotcha. Meaning the search server is pulling from the DB directly. > That’s what the DataImportHandler in Solr does as well. It’d be a > simple single HTTP request to Solr (once the DB stuff is configured, > of course) to have it do full or incremental DB indexing. With the slight difference that custom model logic defined in the rails model class is still involved to preprocess data, index values calculated at indexing time or even have certain records refuse being indexed based on their current state. Having per document boosts depending on some value from the database (i.e. record popularity) is also a classic… Aaf never just pulls data from the db, it always uses rails model objects. Doesn’t make indexing faster of course… […] > XML makes me ill, generally speaking (it has its uses, but for > configuration it is just plain wrong). FULL ACK 🙂 > > > But isn’t Ferret is like 60k lines of C code too?! > > > > true, but I don’t have to compile that every time I deploy my app… > > My point was that Ferret isn’t just Ruby, just a counter point to > your “half a java project”. No one has to recompile Solr either. but the custom analyzer implemented in Java… By saying ‘half a java project’ I didn’t mean solr, but the parts of my application logic that have to be implemented in Java in order to be plugged into solr. But the JRuby route looks promising here of course. > > encapsulate this logic and make it pluggable into the search engine > > library. So less style points for this solution… > > I was just saying 🙂 It’s debatable exactly where in the client- > server spectrum synonym expansion belongs… and it really depends > on the needs of the project. Nothing wrong with a client doing some > user input massaging before a query hits the search server. […] > > > > > > > API, but to me Solr looks like an additional layer of abstraction > > and complexity which I only want to have when it really gives me a > > feature I need. Plus the last time I checked Lucene didn’t need xml > > configuration files 😉 > > I hear ya about the XML config files. And always to be fair to Solr > here, you really only need to set things up from a basic example > configuration that covers most scenarios already - so it really > isn’t necessary to even touch XML config except for tweaking little > things. But I still have to read it in order to see if it fits my needs. Okay, I’ll stop whining about that xml now 😉 […] > > In development environments and especially when it comes to > > automated tests / CI it’s also quite comfortable not having to run > > a separate server but using the short cut directly to the index, > > which isn’t possible with Solr. > > Not true. Solr can work embedded. There is a base SolrServer > abstraction, with an implementation that runs embedded (inside the > same JVM) versus over HTTP. Exactly the same interface for both > operations, using a very simple API (SolrJ, much like Lucene’s basic > API actually). cool, but that won’t work for Rails projects running on MRI and accessing solr via solr-ruby. > No, I don’t have those kinds of tests myself. While I can speak to > Solr’s performance based on what I hear from our clients and the > reports in the mailing lists, I don’t consider myself a performance > savvy person myself. > > I’m curious - what are the numbers of documents being put into > Ferret indexes out there? millions? hundreds of millions? > billions? And are folks doing faceting? Does Ferret have faceting > support? not sure about the billions, but afair an earlier message in this thread stated an index size of 90 million documents with aaf. [Altlaw.org](http://Altlaw.org) has reported an index size of \> 4GB with around 700k documents last fall. The [selfhtml.org](http://selfhtml.org) index has approximately 1 million forum entries indexed, index size around 2GB. Stellr doesn’t ever use more than around 50MB of RAM during indexing and searching this index. I know RAM is cheap and all, but RAM size still has a quite large influence on the price of the server you rent for your app, at least here in germany. Without doubt Solr has much more references in the area of such large installations than ferret/aaf. I for myself never saw aaf as a drop-in solution for indexes of this size, but more as an easy to use out of the box solution for the average rails app with maybe several thousands or tens of thousands records, but I’m happy to see it still works in larger scale setups. Heck, it all began with a simple full text search for my blog 😉 Regarding the faceting - it’s not built into ferret, and aaf doesn’t support it either since I didn’t need it yet, and nobody else requested this feature so far. All in all I think the average usage scenarios of solr and aaf are quite different atm… I’ll try to find the time to benchmark the [selfhtml.org](http://selfhtml.org) data set with solr and stellr. I’ll report my findings here. Cheers, Jens – Jens Krämer Finkenlust 14, 06449 Aschersleben, Germany VAT Id DE251962952 [http://www.jkraemer.net/](http://www.jkraemer.net/) - Blog [http://www.omdb.org/](http://www.omdb.org/) - The new free film database ---
**Author:** ![Fernando\_Parisotto](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/90ced4/32.png) [@Fernando\_Parisotto](https://www.ruby-forum.com/u/Fernando_Parisotto)\ **Post date:** [August 28, 2008, 10:15pm UTC](https://www.ruby-forum.com/t/road-map-of-ferret/146298/26 "2008-08-28T22:15:26Z")
On Aug 28, 2008, at 3:02 PM, Jens K. wrote: > popularity) is also a classic… Aaf never just pulls data from the > db, it always uses rails model objects. Doesn’t make indexing faster > of course… All great points. ActiveRecord is much more pleasant than any other database access that I’ve ever worked with. I don’t generally work with databases personally, though. The bulk of my full-text searching experiences don’t involve databases at all. I suppose the Java counterpart would be Hibernate Search - surely involving a lot more hideous XML and @annotations - ewww. > > basic API actually). > > cool, but that won’t work for Rails projects running on MRI and > accessing solr via solr-ruby. Fair point. Again, the answer comes back to JRuby 😉 Forget MRI. Good point about solr-ruby - it is specifically designed for Solr over HTTP. It wouldn’t take much to refactor it to work with embedded Solr via JRuby though. But if JRuby is a given, it’d be just as easy to work with SolrJ’s API directly. Though for testing purposes, solr-ruby is easily mocked. solr-ruby touts great (98% or something like that) code coverage with unit tests, many of those tests are against solr-ruby’s API with Solr itself mocked. And there are tests that fire up Solr in the background and test that way too for full functional tests. So for unit testing purposes, having Solr running isn’t needed, but it launches plenty fast enough for testing end-to-end if desired. > ever use more than around 50MB of RAM during indexing and searching > this index. I know RAM is cheap and all, but RAM size still has a > quite large influence on the price of the server you rent for your > app, at least here in germany. 90 million is impressive for sure. RAM - well, when Ferret/Stellr does faceting we’ll revisit that discussion 🙂 Solr loves RAM! It still can run in modest environments, but the more RAM you can give it to use for caches (depending on your needs) the better it is. > Without doubt Solr has much more references in the area of such > large installations than ferret/aaf. I for myself never saw aaf as a > drop-in solution for indexes of this size, but more as an easy to > use out of the box solution for the average rails app with maybe > several thousands or tens of thousands records, but I’m happy to > see it still works in larger scale setups. Indeed! ferret: +1 - no question! > Heck, it all began with a simple full text search for my blog 😉 Same for me (though I abandoned it when I realized that regular blogging and server maintenance weren’t for me). > Regarding the faceting - it’s not built into ferret, and aaf doesn’t > support it either since I didn’t need it yet, and nobody else > requested this feature so far. All in all I think the average usage > scenarios of solr and aaf are quite different atm… I’m really surprised by that. Faceting is the major feature that attracts folks to Solr. It’s critical for all of our customers. But yeah, no question that Lucene/Solr and Ferret/Stellr can happily coexist and aren’t necessarily competition for every project. But there definitely are those areas of overlap where a project could go with either solution. And I would definitely not try to shoehorn Solr into a project where it didn’t fit and Ferret worked fine. I’m pragmatic like that. > I’ll try to find the time to benchmark the [selfhtml.org](http://selfhtml.org) data set > with solr and stellr. I’ll report my findings here. Awesome. If you have the data in some easily digestible format, I’d be happy to toss it into Solr and report back numbers from my development machine. Drop me a line offline if you’d like. Erik [Previous page](https://www.ruby-forum.com/t/road-map-of-ferret/146298.md?page=1)