Re: commit, concurrency, full text search

[Venkatraman S]

Before a COMMIT is done , lock is obtained and its released  after the
operation - hence no corruption happens.

On 9/18/07, Dilip.TS [EMAIL PROTECTED] wrote:

 Hi,

 I have a query, when u try for bulk updates, using autoCommit option
 (which
 does commit on regular basis).

 Suppose if another request tries to update before the record is committed
 by
 the first request,
 a) Dont u think these requests step on each other and corrupt the index
 files?
 b) Is there any Lock mechanism involved which prevents this and the rows
 gets unlocked when commit is done?
 c) What happens to the lock if there is the commit is not done? does it
 gets
 unlocked automatically?

 Could you elaborate this?

 Thanks and Regards
 Dilip

 -Original Message-
 From: Mike Klaas [mailto:[EMAIL PROTECTED]
 Sent: Monday, September 17, 2007 11:29 PM
 To: solr-user@lucene.apache.org
 Subject: Re: commit, concurrency, full text search


 On 16-Sep-07, at 11:23 PM, Dilip.TS wrote:

  Hi,
 
  1)How does the commit works with multiple requests?

 Multiple updates?  They block while the commit completes.

  2)Does SOLR handle the concurrency during updates?

 It is parallelized as much as possible, yes.

  3)Does solr support any thing like, if I enclose the keywords
  within quotes,
  then we are searching for exactly those keywords together. Some
  thing like
  google does, for example if I enclose like this java programming
  then it
  should search for this keyword as a whole instead breaking the
  phrase apart.

 Indeed it does.

 see
 http://lucene.apache.org/java/docs/queryparsersyntax.html
 http://wiki.apache.org/solr/SolrQuerySyntax

 -Mike




--

Re: commit, concurrency, full text search

[Chris Hostetter]

:  I have a query, when u try for bulk updates, using autoCommit option (which
: does commit on regular basis).

There is alot of complexity going on when dealing with concurrent updates 
-- some of it at the Lucene level, some at the Solr level.  if you really 
want to udnerstand the details, I suggest you start by reading the 
Lucene-In-Action book, then once you understand the Low level Lucene 
issues, then take a look at the code to see the way Solr manages it's 
IndexReader and IndexWriter.

Or just take my word for it that Solr takes care of the concurrancy issues 
for you.  multiple updates/commits may block, and errors external to Solr 
(ie: OutOfMemory, full disk, hardware failure, power failure, rouge 
processes writing to the index files, etc...) may corrupt your index or 
leave stale lock files lying arround -- but Solr is going to keep it's 
house in order.

-Hoss

commit, concurrency, full text search

[Dilip.TS]

Hi,

1)How does the commit works with multiple requests?
2)Does SOLR handle the concurrency during updates?
3)Does solr support any thing like, if I enclose the keywords within quotes,
then we are searching for exactly those keywords together. Some thing like
google does, for example if I enclose like this java programming  then it
should search for this keyword as a whole instead breaking the phrase apart.

Any help would be highly appreciated.

Thanks in advance.

Regards,
Dilip