Hmmm... I think that means you're using the default data mode
(ordered), which should properly preserve writes if the OS or machine
crashes.
And actually I was wrong before -- even if the mount had
data=writeback, since you are "only" kill -9ing the process (not
crashing the machine), the data mount option doesn't matter. That
option only affects what happens on a crash...
Can you work up a small example showing the problem? And if possible,
turn on IndexWriter's infoStream, capture the output as you index up
until the kill -9, and post that?
Mike
On Mon, Feb 8, 2010 at 3:57 AM, Michael McCandless
<lucene@mikemccandless.com> wrote:
Thanks for sharing...
Software RAID should be perfectly fine for Lucene, in general, unless
the mount is configured to ignore fsync (I think the "data=writeback"
mount option for ext3 does so on Linux).
Can you check the mount options on your RAID filesystem?
Mike
On Mon, Feb 8, 2010 at 2:09 AM, Naama Kraus <naamakraus@gmail.com> wrote:
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)
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--
"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)
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