Interesting, we are running 4.0 - and solr will refuse the start (or reload) the core. But from looking at the code I am not seeing it is doing any writing - but I should digg more...
Are you sure it needs to do writing? Because I am not calling commits, in fact I have deactivated *all* components that write into index, so unless there is something deep inside, which automatically calls the commit, it should never happen. roman On Tue, Jul 2, 2013 at 2:54 PM, Peter Sturge <peter.stu...@gmail.com> wrote: > Hmmm, single lock sounds dangerous. It probably works ok because you've > been [un]lucky. > For example, even with a RO instance, you still need to do a commit in > order to reload caches/changes from the other instance. > What happens if this commit gets called in the middle of the other > instance's commit? I've not tested this scenario, but it's very possible > with a 'single' lock the results are indeterminate. > If the 'single' lock mechanism is making assumptions e.g. no other process > will interfere, and then one does, the Lucene index could very well get > corrupted. > > For the error you're seeing using 'native', we use native lockType for both > write and RO instances, and it works fine - no contention. > Which version of Solr are you using? Perhaps there's been a change in > behaviour? > > Peter > > > On Tue, Jul 2, 2013 at 7:30 PM, Roman Chyla <roman.ch...@gmail.com> wrote: > > > as i discovered, it is not good to use 'native' locktype in this > scenario, > > actually there is a note in the solrconfig.xml which says the same > > > > when a core is reloaded and solr tries to grab lock, it will fail - even > if > > the instance is configured to be read-only, so i am using 'single' lock > for > > the readers and 'native' for the writer, which seems to work OK > > > > roman > > > > > > On Fri, Jun 7, 2013 at 9:05 PM, Roman Chyla <roman.ch...@gmail.com> > wrote: > > > > > I have auto commit after 40k RECs/1800secs. But I only tested with > manual > > > commit, but I don't see why it should work differently. > > > Roman > > > On 7 Jun 2013 20:52, "Tim Vaillancourt" <t...@elementspace.com> wrote: > > > > > >> If it makes you feel better, I also considered this approach when I > was > > in > > >> the same situation with a separate indexer and searcher on one > Physical > > >> linux machine. > > >> > > >> My main concern was "re-using" the FS cache between both instances - > If > > I > > >> replicated to myself there would be two independent copies of the > index, > > >> FS-cached separately. > > >> > > >> I like the suggestion of using autoCommit to reload the index. If I'm > > >> reading that right, you'd set an autoCommit on 'zero docs changing', > or > > >> just 'every N seconds'? Did that work? > > >> > > >> Best of luck! > > >> > > >> Tim > > >> > > >> > > >> On 5 June 2013 10:19, Roman Chyla <roman.ch...@gmail.com> wrote: > > >> > > >> > So here it is for a record how I am solving it right now: > > >> > > > >> > Write-master is started with: -Dmontysolr.warming.enabled=false > > >> > -Dmontysolr.write.master=true -Dmontysolr.read.master= > > >> > http://localhost:5005 > > >> > Read-master is started with: -Dmontysolr.warming.enabled=true > > >> > -Dmontysolr.write.master=false > > >> > > > >> > > > >> > solrconfig.xml changes: > > >> > > > >> > 1. all index changing components have this bit, > > >> > enable="${montysolr.master:true}" - ie. > > >> > > > >> > <updateHandler class="solr.DirectUpdateHandler2" > > >> > enable="${montysolr.master:true}"> > > >> > > > >> > 2. for cache warming de/activation > > >> > > > >> > <listener event="newSearcher" > > >> > class="solr.QuerySenderListener" > > >> > enable="${montysolr.enable.warming:true}">... > > >> > > > >> > 3. to trigger refresh of the read-only-master (from write-master): > > >> > > > >> > <listener event="postCommit" > > >> > class="solr.RunExecutableListener" > > >> > enable="${montysolr.master:true}"> > > >> > <str name="exe">curl</str> > > >> > <str name="dir">.</str> > > >> > <bool name="wait">false</bool> > > >> > <arr name="args"> <str>${montysolr.read.master: > http://localhost > > >> > > > >> > > > >> > > > }/solr/admin/cores?wt=json&action=RELOAD&core=collection1</str></arr> > > >> > </listener> > > >> > > > >> > This works, I still don't like the reload of the whole core, but it > > >> seems > > >> > like the easiest thing to do now. > > >> > > > >> > -- roman > > >> > > > >> > > > >> > On Wed, Jun 5, 2013 at 12:07 PM, Roman Chyla <roman.ch...@gmail.com > > > > >> > wrote: > > >> > > > >> > > Hi Peter, > > >> > > > > >> > > Thank you, I am glad to read that this usecase is not alien. > > >> > > > > >> > > I'd like to make the second instance (searcher) completely > > read-only, > > >> so > > >> > I > > >> > > have disabled all the components that can write. > > >> > > > > >> > > (being lazy ;)) I'll probably use > > >> > > http://wiki.apache.org/solr/CollectionDistribution to call the > curl > > >> > after > > >> > > commit, or write some IndexReaderFactory that checks for changes > > >> > > > > >> > > The problem with calling the 'core reload' - is that it seems lots > > of > > >> > work > > >> > > for just opening a new searcher, eeekkk...somewhere I read that it > > is > > >> > cheap > > >> > > to reload a core, but re-opening the index searches must be > > definitely > > >> > > cheaper... > > >> > > > > >> > > roman > > >> > > > > >> > > > > >> > > On Wed, Jun 5, 2013 at 4:03 AM, Peter Sturge < > > peter.stu...@gmail.com > > >> > >wrote: > > >> > > > > >> > >> Hi, > > >> > >> We use this very same scenario to great effect - 2 instances > using > > >> the > > >> > >> same > > >> > >> dataDir with many cores - 1 is a writer (no caching), the other > is > > a > > >> > >> searcher (lots of caching). > > >> > >> To get the searcher to see the index changes from the writer, you > > >> need > > >> > the > > >> > >> searcher to do an empty commit - i.e. you invoke a commit with 0 > > >> > >> documents. > > >> > >> This will refresh the caches (including autowarming), [re]build > the > > >> > >> relevant searchers etc. and make any index changes visible to the > > RO > > >> > >> instance. > > >> > >> Also, make sure to use <lockType>native</lockType> in > > solrconfig.xml > > >> to > > >> > >> ensure the two instances don't try to commit at the same time. > > >> > >> There are several ways to trigger a commit: > > >> > >> Call commit() periodically within your own code. > > >> > >> Use autoCommit in solrconfig.xml. > > >> > >> Use an RPC/IPC mechanism between the 2 instance processes to tell > > the > > >> > >> searcher the index has changed, then call commit when called > (more > > >> > complex > > >> > >> coding, but good if the index changes on an ad-hoc basis). > > >> > >> Note, doing things this way isn't really suitable for an NRT > > >> > environment. > > >> > >> > > >> > >> HTH, > > >> > >> Peter > > >> > >> > > >> > >> > > >> > >> > > >> > >> On Tue, Jun 4, 2013 at 11:23 PM, Roman Chyla < > > roman.ch...@gmail.com> > > >> > >> wrote: > > >> > >> > > >> > >> > Replication is fine, I am going to use it, but I wanted it for > > >> > instances > > >> > >> > *distributed* across several (physical) machines - but here I > > have > > >> one > > >> > >> > physical machine, it has many cores. I want to run 2 instances > of > > >> solr > > >> > >> > because I think it has these benefits: > > >> > >> > > > >> > >> > 1) I can give less RAM to the writer (4GB), and use more RAM > for > > >> the > > >> > >> > searcher (28GB) > > >> > >> > 2) I can deactivate warming for the writer and keep it for the > > >> > searcher > > >> > >> > (this considerably speeds up indexing - each time we commit, > the > > >> > server > > >> > >> is > > >> > >> > rebuilding a citation network of 80M edges) > > >> > >> > 3) saving disk space and better OS caching (OS should be able > to > > >> use > > >> > >> more > > >> > >> > RAM for the caching, which should result in faster operations - > > the > > >> > two > > >> > >> > processes are accessing the same index) > > >> > >> > > > >> > >> > Maybe I should just forget it and go with the replication, but > it > > >> > >> doesn't > > >> > >> > 'feel right' IFF it is on the same physical machine. And Lucene > > >> > >> > specifically has a method for discovering changes and > re-opening > > >> the > > >> > >> index > > >> > >> > (DirectoryReader.openIfChanged) > > >> > >> > > > >> > >> > Am I not seeing something? > > >> > >> > > > >> > >> > roman > > >> > >> > > > >> > >> > > > >> > >> > > > >> > >> > On Tue, Jun 4, 2013 at 5:30 PM, Jason Hellman < > > >> > >> > jhell...@innoventsolutions.com> wrote: > > >> > >> > > > >> > >> > > Roman, > > >> > >> > > > > >> > >> > > Could you be more specific as to why replication doesn't meet > > >> your > > >> > >> > > requirements? It was geared explicitly for this purpose, > > >> including > > >> > >> the > > >> > >> > > automatic discovery of changes to the data on the index > master. > > >> > >> > > > > >> > >> > > Jason > > >> > >> > > > > >> > >> > > On Jun 4, 2013, at 1:50 PM, Roman Chyla < > roman.ch...@gmail.com > > > > > >> > >> wrote: > > >> > >> > > > > >> > >> > > > OK, so I have verified the two instances can run alongside, > > >> > sharing > > >> > >> the > > >> > >> > > > same datadir > > >> > >> > > > > > >> > >> > > > All update handlers are unaccessible in the read-only > master > > >> > >> > > > > > >> > >> > > > <updateHandler class="solr.DirectUpdateHandler2" > > >> > >> > > > enable="${solr.can.write:true}"> > > >> > >> > > > > > >> > >> > > > java -Dsolr.can.write=false ..... > > >> > >> > > > > > >> > >> > > > And I can reload the index manually: > > >> > >> > > > > > >> > >> > > > curl " > > >> > >> > > > > > >> > >> > > > > >> > >> > > > >> > >> > > >> > > > >> > > > http://localhost:5005/solr/admin/cores?wt=json&action=RELOAD&core=collection1 > > >> > >> > > > " > > >> > >> > > > > > >> > >> > > > But this is not an ideal solution; I'd like for the > read-only > > >> > >> server to > > >> > >> > > > discover index changes on its own. Any pointers? > > >> > >> > > > > > >> > >> > > > Thanks, > > >> > >> > > > > > >> > >> > > > roman > > >> > >> > > > > > >> > >> > > > > > >> > >> > > > On Tue, Jun 4, 2013 at 2:01 PM, Roman Chyla < > > >> > roman.ch...@gmail.com> > > >> > >> > > wrote: > > >> > >> > > > > > >> > >> > > >> Hello, > > >> > >> > > >> > > >> > >> > > >> I need your expert advice. I am thinking about running two > > >> > >> instances > > >> > >> > of > > >> > >> > > >> solr that share the same datadirectory. The *reason* > being: > > >> > >> indexing > > >> > >> > > >> instance is constantly building cache after every commit > (we > > >> > have a > > >> > >> > big > > >> > >> > > >> cache) and this slows it down. But indexing doesn't need > > much > > >> > RAM, > > >> > >> > only > > >> > >> > > the > > >> > >> > > >> search does (and server has lots of CPUs) > > >> > >> > > >> > > >> > >> > > >> So, it is like having two solr instances > > >> > >> > > >> > > >> > >> > > >> 1. solr-indexing-master > > >> > >> > > >> 2. solr-read-only-master > > >> > >> > > >> > > >> > >> > > >> In the solrconfig.xml I can disable update components, It > > >> should > > >> > be > > >> > >> > > fine. > > >> > >> > > >> However, I don't know how to 'trigger' index re-opening on > > (2) > > >> > >> after > > >> > >> > the > > >> > >> > > >> commit happens on (1). > > >> > >> > > >> > > >> > >> > > >> Ideally, the second instance could monitor the disk and > > >> re-open > > >> > >> disk > > >> > >> > > after > > >> > >> > > >> new files appear there. Do I have to implement custom > > >> > >> > > IndexReaderFactory? > > >> > >> > > >> Or something else? > > >> > >> > > >> > > >> > >> > > >> Please note: I know about the replication, this usecase is > > >> IMHO > > >> > >> > slightly > > >> > >> > > >> different - in fact, write-only-master (1) is also a > > >> replication > > >> > >> > master > > >> > >> > > >> > > >> > >> > > >> Googling turned out only this > > >> > >> > > >> > > >> > >> > > http://comments.gmane.org/gmane.comp.jakarta.lucene.solr.user/71912- > > >> > >> > > no > > >> > >> > > >> pointers there. > > >> > >> > > >> > > >> > >> > > >> But If I am approaching the problem wrongly, please don't > > >> > hesitate > > >> > >> to > > >> > >> > > >> 're-educate' me :) > > >> > >> > > >> > > >> > >> > > >> Thanks! > > >> > >> > > >> > > >> > >> > > >> roman > > >> > >> > > >> > > >> > >> > > > > >> > >> > > > > >> > >> > > > >> > >> > > >> > > > > >> > > > > >> > > > >> > > > > > >
