<s>
Solr	B-Language
(	O
pronounced	O
"	O
solar	O
"	O
)	O
is	O
an	O
open-source	B-Application
enterprise-search	B-Application
platform	O
,	O
written	O
in	O
Java	B-Language
.	O
</s>
<s>
Its	O
major	O
features	O
include	O
full-text	B-Application
search	I-Application
,	O
hit	O
highlighting	O
,	O
faceted	O
search	B-Application
,	O
real-time	O
indexing	O
,	O
dynamic	O
clustering	O
,	O
database	O
integration	O
,	O
NoSQL	B-General_Concept
features	O
and	O
rich	O
document	O
(	O
e.g.	O
,	O
Word	B-Application
,	O
PDF	B-Application
)	O
handling	O
.	O
</s>
<s>
Providing	O
distributed	O
search	B-Application
and	O
index	B-Application
replication	O
,	O
Solr	B-Language
is	O
designed	O
for	O
scalability	O
and	O
fault	B-General_Concept
tolerance	I-General_Concept
.	O
</s>
<s>
Solr	B-Language
is	O
widely	O
used	O
for	O
enterprise	B-Application
search	I-Application
and	O
analytics	O
use	O
cases	O
and	O
has	O
an	O
active	O
development	O
community	O
and	O
regular	O
releases	O
.	O
</s>
<s>
Solr	B-Language
runs	O
as	O
a	O
standalone	O
full-text	B-Application
search	I-Application
server	O
.	O
</s>
<s>
It	O
uses	O
the	O
Lucene	B-Language
Java	B-Language
search	B-Application
library	O
at	O
its	O
core	O
for	O
full-text	B-Application
indexing	O
and	O
search	B-Application
,	O
and	O
has	O
REST-like	O
HTTP/XML	O
and	O
JSON	B-General_Concept
APIs	B-General_Concept
that	O
make	O
it	O
usable	O
from	O
most	O
popular	O
programming	O
languages	O
.	O
</s>
<s>
Solr	B-Language
's	O
external	O
configuration	O
allows	O
it	O
to	O
be	O
tailored	O
to	O
many	O
types	O
of	O
applications	O
without	O
Java	B-Language
coding	O
,	O
and	O
it	O
has	O
a	O
plugin	O
architecture	O
to	O
support	O
more	O
advanced	O
customization	O
.	O
</s>
<s>
Apache	B-Language
Solr	I-Language
is	O
developed	O
in	O
an	O
open	O
,	O
collaborative	O
manner	O
by	O
the	O
Apache	B-Language
Solr	I-Language
project	O
at	O
the	O
Apache	O
Software	O
Foundation	O
.	O
</s>
<s>
In	O
2004	O
,	O
Solr	B-Language
was	O
created	O
by	O
Yonik	O
Seeley	O
at	O
CNET	O
Networks	O
as	O
an	O
in-house	O
project	O
to	O
add	O
search	B-Application
capability	O
for	O
the	O
company	O
website	O
.	O
</s>
<s>
In	O
January	O
2007	O
,	O
Solr	B-Language
graduated	O
from	O
incubation	O
status	O
into	O
a	O
standalone	O
top-level	O
project	O
(	O
TLP	O
)	O
and	O
grew	O
steadily	O
with	O
accumulated	O
features	O
,	O
thereby	O
attracting	O
users	O
,	O
contributors	O
,	O
and	O
committers	O
.	O
</s>
<s>
In	O
September	O
2008	O
,	O
Solr	B-Language
1.3	O
was	O
released	O
including	O
distributed	O
search	B-Application
capabilities	O
and	O
performance	O
enhancements	O
among	O
many	O
others	O
.	O
</s>
<s>
In	O
January	O
2009	O
,	O
Yonik	O
Seeley	O
along	O
with	O
Grant	O
Ingersoll	O
and	O
Erik	O
Hatcher	O
joined	O
Lucidworks	O
(	O
formerly	O
Lucid	O
Imagination	O
)	O
,	O
the	O
first	O
company	O
providing	O
commercial	O
support	O
and	O
training	O
for	O
Apache	B-Language
Solr	I-Language
search	B-Application
technologies	O
.	O
</s>
<s>
Since	O
then	O
,	O
support	O
offerings	O
around	O
Solr	B-Language
have	O
been	O
abundant	O
.	O
</s>
<s>
In	O
November	O
2009	O
,	O
saw	O
the	O
release	O
of	O
Solr	B-Language
1.4	O
.	O
</s>
<s>
This	O
version	O
introduced	O
enhancements	O
in	O
indexing	O
,	O
searching	O
and	O
faceting	O
along	O
with	O
many	O
other	O
improvements	O
such	O
as	O
rich	O
document	O
processing	O
(	O
PDF	B-Application
,	O
Word	B-Application
,	O
HTML	B-Language
)	O
,	O
Search	B-Application
Results	O
clustering	O
based	O
on	O
Carrot2	B-Application
and	O
also	O
improved	O
database	O
integration	O
.	O
</s>
<s>
In	O
March	O
2010	O
,	O
the	O
Lucene	B-Language
and	O
Solr	B-Language
projects	O
merged	O
.	O
</s>
<s>
In	O
2011	O
,	O
the	O
Solr	B-Language
version	O
number	O
scheme	O
was	O
changed	O
in	O
order	O
to	O
match	O
that	O
of	O
Lucene	B-Language
.	O
</s>
<s>
After	O
Solr	B-Language
1.4	O
,	O
the	O
next	O
release	O
of	O
Solr	B-Language
was	O
labeled	O
3.1	O
,	O
in	O
order	O
to	O
keep	O
Solr	B-Language
and	O
Lucene	B-Language
on	O
the	O
same	O
version	O
number	O
.	O
</s>
<s>
In	O
October	O
2012	O
,	O
Solr	B-Language
version	O
4.0	O
was	O
released	O
,	O
including	O
the	O
new	O
SolrCloud	O
feature	O
.	O
</s>
<s>
2013	O
and	O
2014	O
saw	O
a	O
number	O
of	O
Solr	B-Language
releases	O
in	O
the	O
4.x	O
line	O
,	O
steadily	O
growing	O
the	O
feature	O
set	O
and	O
improving	O
reliability	O
.	O
</s>
<s>
In	O
February	O
2015	O
,	O
Solr	B-Language
5.0	O
was	O
released	O
,	O
the	O
first	O
release	O
where	O
Solr	B-Language
is	O
packaged	O
as	O
a	O
standalone	O
application	O
,	O
ending	O
official	O
support	O
for	O
deploying	O
Solr	B-Language
as	O
a	O
war	B-Language
.	O
</s>
<s>
Solr	B-Language
5.3	O
featured	O
a	O
built-in	O
pluggable	O
Authentication	O
and	O
Authorization	O
framework	O
.	O
</s>
<s>
In	O
April	O
2016	O
,	O
Solr	B-Language
6.0	O
was	O
released	O
.	O
</s>
<s>
In	O
September	O
2017	O
,	O
Solr	B-Language
7.0	O
was	O
released	O
.	O
</s>
<s>
In	O
March	O
2019	O
,	O
Solr	B-Language
8.0	O
was	O
released	O
including	O
many	O
bugfixes	O
and	O
component	O
updates	O
.	O
</s>
<s>
Solr	B-Language
nodes	O
can	O
now	O
listen	O
and	O
serve	O
HTTP/2	O
requests	O
.	O
</s>
<s>
Be	O
aware	O
that	O
by	O
default	O
,	O
internal	O
requests	O
are	O
also	O
sent	O
by	O
using	O
HTTP/2	O
.	O
</s>
<s>
In	O
November	O
2020	O
,	O
Bloomberg	O
donated	O
the	O
to	O
the	O
Lucene/Solr	O
project	O
.	O
</s>
<s>
The	O
Solr	B-Language
Operator	O
helps	O
deploy	O
and	O
run	O
Solr	B-Language
in	O
Kubernetes	B-General_Concept
.	O
</s>
<s>
In	O
February	O
2021	O
,	O
Solr	B-Language
was	O
established	O
as	O
a	O
separate	O
Apache	O
project	O
(	O
TLP	O
)	O
,	O
independent	O
from	O
Lucene	B-Language
.	O
</s>
<s>
In	O
May	O
2022	O
,	O
Solr	B-Language
9.0	O
was	O
released	O
,	O
as	O
the	O
first	O
release	O
independent	O
from	O
Lucene	B-Language
,	O
requiring	O
Java	B-Language
11	O
,	O
and	O
with	O
highlights	O
such	O
as	O
KNN	O
"	O
Neural	O
"	O
search	B-Application
,	O
better	O
modularization	O
,	O
more	O
security	O
plugins	O
and	O
more	O
.	O
</s>
<s>
In	O
order	O
to	O
search	B-Application
a	O
document	O
,	O
Apache	B-Language
Solr	I-Language
performs	O
the	O
following	O
operations	O
in	O
sequence	O
:	O
</s>
<s>
Mapping	O
:	O
Solr	B-Language
maps	O
the	O
user	O
query	O
to	O
the	O
documents	O
stored	O
in	O
the	O
database	O
to	O
find	O
the	O
appropriate	O
result	O
.	O
</s>
<s>
Solr	B-Language
has	O
both	O
individuals	O
and	O
companies	O
who	O
contribute	O
new	O
features	O
and	O
bug	O
fixes	O
.	O
</s>
<s>
Solr	B-Language
is	O
bundled	O
as	O
the	O
built-in	O
search	B-Application
in	O
many	O
applications	O
such	O
as	O
content	B-Protocol
management	I-Protocol
systems	I-Protocol
and	O
enterprise	B-Application
content	I-Application
management	I-Application
systems	I-Application
.	O
</s>
<s>
Hadoop	B-Application
distributions	O
from	O
Cloudera	B-General_Concept
,	O
Hortonworks	B-Application
and	O
MapR	B-General_Concept
all	O
bundle	O
Solr	B-Language
as	O
the	O
search	B-Application
engine	O
for	O
their	O
products	O
marketed	O
for	O
big	B-Application
data	I-Application
.	O
</s>
<s>
DataStax	B-General_Concept
DSE	O
integrates	O
Solr	B-Language
as	O
a	O
search	B-Application
engine	O
with	O
Cassandra	B-Application
.	O
</s>
<s>
Solr	B-Language
is	O
supported	O
as	O
an	O
end	O
point	O
in	O
various	O
data	O
processing	O
frameworks	O
and	O
Enterprise	B-Architecture
integration	I-Architecture
frameworks	O
.	O
</s>
<s>
Solr	B-Language
exposes	O
industry	O
standard	O
HTTP	B-Protocol
REST-like	O
APIs	B-General_Concept
with	O
both	O
XML	B-Protocol
and	O
JSON	B-General_Concept
support	O
,	O
and	O
will	O
integrate	O
with	O
any	O
system	O
or	O
programming	O
language	O
supporting	O
these	O
standards	O
.	O
</s>
<s>
For	O
ease	O
of	O
use	O
there	O
are	O
also	O
client	O
libraries	O
available	O
for	O
Java	B-Language
,	O
C#	B-Application
,	O
PHP	B-Application
,	O
Python	B-Language
,	O
Ruby	B-Language
and	O
most	O
other	O
popular	O
programming	O
languages	O
.	O
</s>
