lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Naama Kraus <naamakr...@gmail.com>
Subject Re: Problems with IndexWriter#commit() on Linux
Date Mon, 08 Feb 2010 07:09:53 GMT
Hi All,

I am back to this one after some while.
It appears the file system I was using resides on software RAID disks. I ran
the same code on the same Linux machine, but on another file system residing
on SCSI disks. I didn't observe the problem there.
Both file systems are ext3.
So I am guessing the problem relates to the RAID disks.

I looked again at commit() API, and the following comment may be explaining:

"Note that this operation calls Directory.sync on the index files. That call
should not return until the file contents & metadata are on stable storage.
For FSDirectory, this calls the OS's fsync. But, beware: some hardware
devices may in fact cache writes even during fsync, and return before the
bits are actually on stable storage, to give the appearance of faster
performance. If you have such a device, and it does not have a battery
backup (for example) then on power loss it may still lose data. Lucene
cannot guarantee consistency on such devices."

Well, for me, running on the SCSI disks is just fine, I wanted to anyway
share my experience.

Naama

On Fri, Jan 8, 2010 at 12:09 AM, Naama Kraus <naamakraus@gmail.com> wrote:

> Thanks all for the hints, I'll get back to my code and do some additional
> checks.
> Naama
>
>
> On Thu, Jan 7, 2010 at 6:57 PM, Michael McCandless <
> lucene@mikemccandless.com> wrote:
>
>> kill -9 is harsh, but, perfectly fine from Lucene's standpoint.
>> Likewise if the OS or JVM crashes, power is suddenly lost, the index
>> will just fallback to the last successful commit.  What will cause
>> corruption is if you have bit errors happening somewhere in the
>> machine... or if two writers are accidentally allowed to be open on
>> one index... then you're in trouble.
>>
>> What IO system (filesystem & hardware) are you using on Linux?
>> Boiling down to a smallish test case can help to isolate the
>> problem...
>>
>> Mike
>>
>> On Thu, Jan 7, 2010 at 11:51 AM, Erick Erickson <erickerickson@gmail.com>
>> wrote:
>> > Can you show us the code where you commit?
>> >
>> > And how do you kill your process? Kill -9 is...er...harsh....
>> >
>> > Yeah, I'm wondering whether the index file size *stays*
>> > changed after you kill you process. If it keeps its
>> > growing on every run (after you kill your process
>> > multiple times), then I'd suspect that you aren't
>> > adding documents like you think you are. Perhaps
>> > different fields, different analyzers, etc.
>> >
>> > Luke should show you the largest document by ID,
>> > as well as document counts. Comparing changes
>> > in the document count and the max doc ID should
>> > tell you something...
>> >
>> > Is it possible that you are updating existing docs
>> > rather than adding new ones?
>> >
>> > Best
>> > Erick
>> >
>> > On Thu, Jan 7, 2010 at 10:41 AM, Naama Kraus <naamakraus@gmail.com>
>> wrote:
>> >
>> >> Thanks dor the input.
>> >>
>> >> 1. While the process is running, I do see the index files growing on
>> disk
>> >> and the time stamps changing. Should I see a change in size right after
>> >> killing the process, is that what you mean ?
>> >> 2. Yes, same directory is being used for indexing and search.
>> >> 3. Didn't try Luke, good idea. Though I wonder, the same code runs well
>> on
>> >> Windows.
>> >>
>> >> Naama
>> >>
>> >> On Thu, Jan 7, 2010 at 3:37 PM, Erick Erickson <
>> erickerickson@gmail.com
>> >> >wrote:
>> >>
>> >> > Several questions:
>> >> > 1> are the index files larger after you kill your process?
>> >> >    Or have the timestamps changed?
>> >> > 2> are you absolutely sure that your indexer, when you
>> >> >     add documents, is pointing at the same directory your
>> >> >     search is pointing to?
>> >> > 3> Have you gotten a copy of Luke and examined your index
>> >> >     to see if, perhaps, your documents aren't being added the
>> >> >     way you think they are?
>> >> >
>> >> > Erick
>> >> >
>> >> > On Thu, Jan 7, 2010 at 7:13 AM, Naama Kraus <naamakraus@gmail.com>
>> >> wrote:
>> >> >
>> >> > > Hi,
>> >> > >
>> >> > > I am using IndexWriter#commit() methods in my program to commit
>> >> document
>> >> > > additions to the index. I do that once in a while, after a bunch
of
>> >> > > documents were added. Since my indexing process is long, I want
to
>> make
>> >> > > sure
>> >> > > I don't loose too many additions in case of a crash.
>> >> > > When running on Windows, things work as expected. But when running
>> my
>> >> > code
>> >> > > on Linux, seems like commit() has no effect. If I kill my program
>> and
>> >> > then
>> >> > > restart it, I don't see documents that I added and then committed
>> (they
>> >> > are
>> >> > > not returned by a search operation).
>> >> > > I am running Lucene 3.0.0
>> >> > >
>> >> > > Can anyone help ?
>> >> > >
>> >> > > Thanks, Naama
>> >> > >
>> >> > > --
>> >> > > "If you want your children to be intelligent, read them fairy
>> tales. If
>> >> > you
>> >> > > want them to be more intelligent, read them more fairy tales."
>> >> > > "What really interests me is whether God had any choice in the
>> creation
>> >> > of
>> >> > > the world."
>> >> > > (Albert Einstein)
>> >> > >
>> >> >
>> >>
>> >>
>> >>
>> >> --
>> >> "If you want your children to be intelligent, read them fairy tales. If
>> you
>> >> want them to be more intelligent, read them more fairy tales."
>> >> "What really interests me is whether God had any choice in the creation
>> of
>> >> the world."
>> >> (Albert Einstein)
>> >>
>> >
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
>> For additional commands, e-mail: java-user-help@lucene.apache.org
>>
>>
>
>
> --
> "If you want your children to be intelligent, read them fairy tales. If you
> want them to be more intelligent, read them more fairy tales."
> "What really interests me is whether God had any choice in the creation of
> the world."
> (Albert Einstein)
>



-- 
"If you want your children to be intelligent, read them fairy tales. If you
want them to be more intelligent, read them more fairy tales."
"What really interests me is whether God had any choice in the creation of
the world."
"A table, a chair, a bowl of fruit and a violin; what else does a man need
to be happy? "
(Albert Einstein)

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message