<s>
Elasticsearch	B-Application
is	O
a	O
search	B-Application
engine	O
based	O
on	O
the	O
Lucene	B-Language
library	O
.	O
</s>
<s>
It	O
provides	O
a	O
distributed	O
,	O
multitenant-capable	O
full-text	B-Application
search	I-Application
engine	O
with	O
an	O
HTTP	B-Protocol
web	O
interface	O
and	O
schema-free	O
JSON	B-General_Concept
documents	O
.	O
</s>
<s>
Elasticsearch	B-Application
is	O
developed	O
in	O
Java	B-Language
and	O
is	O
dual-licensed	O
under	O
the	O
source-available	B-License
Server	O
Side	O
Public	O
License	O
and	O
the	O
Elastic	O
license	O
,	O
while	O
other	O
parts	O
fall	O
under	O
the	O
proprietary	B-Application
(	O
source-available	B-License
)	O
Elastic	O
License	O
.	O
</s>
<s>
Official	O
clients	O
are	O
available	O
in	O
Java	B-Language
,	O
.NET	B-Application
(	O
C#	B-Application
)	O
,	O
PHP	B-Application
,	O
Python	B-Language
,	O
Ruby	B-Language
and	O
many	O
other	O
languages	O
.	O
</s>
<s>
According	O
to	O
the	O
DB-Engines	B-Application
ranking	I-Application
,	O
Elasticsearch	B-Application
is	O
the	O
most	O
popular	O
enterprise	O
search	B-Application
engine	O
.	O
</s>
<s>
Shay	B-Application
Banon	I-Application
created	O
the	O
precursor	O
to	O
Elasticsearch	B-Application
,	O
called	O
Compass	O
,	O
in	O
2004	O
.	O
</s>
<s>
While	O
thinking	O
about	O
the	O
third	O
version	O
of	O
Compass	O
he	O
realized	O
that	O
it	O
would	O
be	O
necessary	O
to	O
rewrite	O
big	O
parts	O
of	O
Compass	O
to	O
"	O
create	O
a	O
scalable	O
search	B-Application
solution	O
"	O
.	O
</s>
<s>
So	O
he	O
created	O
"	O
a	O
solution	O
built	O
from	O
the	O
ground	O
up	O
to	O
be	O
distributed	O
"	O
and	O
used	O
a	O
common	O
interface	O
,	O
JSON	B-General_Concept
over	O
HTTP	B-Protocol
,	O
suitable	O
for	O
programming	O
languages	O
other	O
than	O
Java	B-Language
as	O
well	O
.	O
</s>
<s>
Shay	B-Application
Banon	I-Application
released	O
the	O
first	O
version	O
of	O
Elasticsearch	B-Application
in	O
February	O
2010	O
.	O
</s>
<s>
Elastic	O
NV	O
was	O
founded	O
in	O
2012	O
to	O
provide	O
commercial	O
services	O
and	O
products	O
around	O
Elasticsearch	B-Application
and	O
related	O
software	O
.	O
</s>
<s>
Additional	O
funders	O
include	O
Benchmark	O
Capital	O
and	O
Index	B-Application
Ventures	O
.	O
</s>
<s>
In	O
March	O
2015	O
,	O
the	O
company	O
Elasticsearch	B-Application
changed	O
its	O
name	O
to	O
Elastic	O
.	O
</s>
<s>
In	O
January	O
2021	O
,	O
Elastic	O
announced	O
that	O
starting	O
with	O
version	O
7.11	O
,	O
they	O
would	O
be	O
relicensing	O
their	O
Apache	O
2.0	O
licensed	O
code	O
in	O
Elasticsearch	B-Application
and	O
Kibana	B-Application
to	O
be	O
dual	O
licensed	O
under	O
Server	O
Side	O
Public	O
License	O
and	O
the	O
Elastic	O
License	O
,	O
neither	O
of	O
which	O
is	O
recognized	O
as	O
an	O
open-source	B-License
license	O
.	O
</s>
<s>
Elastic	O
blamed	O
Amazon	B-Application
Web	I-Application
Services	I-Application
(	O
AWS	B-Application
)	O
for	O
this	O
change	O
,	O
objecting	O
to	O
AWS	B-Application
offering	O
Elasticsearch	B-Application
and	O
Kibana	B-Application
as	B-Architecture
a	I-Architecture
service	I-Architecture
directly	O
to	O
consumers	O
and	O
claiming	O
that	O
AWS	B-Application
was	O
not	O
appropriately	O
collaborating	O
with	O
Elastic	O
.	O
</s>
<s>
Critics	O
of	O
the	O
re-licensing	O
decision	O
predicted	O
that	O
it	O
would	O
harm	O
Elastic	O
's	O
ecosystem	O
and	O
noted	O
that	O
Elastic	O
had	O
previously	O
promised	O
to	O
"	O
never	O
....	O
change	O
the	O
license	O
of	O
the	O
Apache	O
2.0	O
code	O
of	O
Elasticsearch	B-Application
,	O
Kibana	B-Application
,	O
Beats	O
,	O
and	O
Logstash	B-Application
"	O
.	O
</s>
<s>
Amazon	O
responded	O
with	O
plans	O
to	O
fork	B-Application
the	O
projects	O
and	O
continue	O
development	O
under	O
Apache	O
License	O
2.0	O
.	O
</s>
<s>
Other	O
users	O
of	O
the	O
ElasticSearch	B-Application
ecosystem	O
,	O
including	O
Logz.io,	O
CrateDB	B-Application
and	O
Aiven	O
,	O
also	O
committed	O
to	O
the	O
need	O
for	O
a	O
fork	B-Application
,	O
leading	O
to	O
a	O
discussion	O
of	O
how	O
to	O
coordinate	O
the	O
open	B-License
source	I-License
efforts	O
.	O
</s>
<s>
Due	O
to	O
potential	O
trademark	O
issues	O
with	O
using	O
the	O
name	O
"	O
Elasticsearch	B-Application
"	O
,	O
AWS	B-Application
rebranded	O
their	O
fork	B-Application
as	O
OpenSearch	B-Application
in	O
April	O
2021	O
.	O
</s>
<s>
Elasticsearch	B-Application
can	O
be	O
used	O
to	O
search	B-Application
any	O
kind	O
of	O
document	O
.	O
</s>
<s>
It	O
provides	O
scalable	O
search	B-Application
,	O
has	O
near	O
real-time	O
search	B-Application
,	O
and	O
supports	O
multitenancy	B-Architecture
.	O
</s>
<s>
"	O
Elasticsearch	B-Application
is	O
distributed	O
,	O
which	O
means	O
that	O
indices	O
can	O
be	O
divided	O
into	O
shards	B-General_Concept
and	O
each	O
shard	B-General_Concept
can	O
have	O
zero	O
or	O
more	O
replicas	O
.	O
</s>
<s>
Each	O
node	O
hosts	O
one	O
or	O
more	O
shards	B-General_Concept
and	O
acts	O
as	O
a	O
coordinator	O
to	O
delegate	O
operations	O
to	O
the	O
correct	O
shard(s )	O
.	O
</s>
<s>
Related	O
data	O
is	O
often	O
stored	O
in	O
the	O
same	O
index	B-Application
,	O
which	O
consists	O
of	O
one	O
or	O
more	O
primary	O
shards	B-General_Concept
,	O
and	O
zero	O
or	O
more	O
replica	O
shards	B-General_Concept
.	O
</s>
<s>
Once	O
an	O
index	B-Application
has	O
been	O
created	O
,	O
the	O
number	O
of	O
primary	O
shards	B-General_Concept
cannot	O
be	O
changed	O
.	O
</s>
<s>
Elasticsearch	B-Application
is	O
developed	O
alongside	O
the	O
data	O
collection	O
and	O
log-parsing	O
engine	O
Logstash	B-Application
,	O
the	O
analytics	O
and	O
visualization	O
platform	O
Kibana	B-Application
,	O
and	O
the	O
collection	O
of	O
lightweight	O
data	O
shippers	O
called	O
Beats	O
.	O
</s>
<s>
The	O
four	O
products	O
are	O
designed	O
for	O
use	O
as	O
an	O
integrated	O
solution	O
,	O
referred	O
to	O
as	O
the	O
"	O
Elastic	B-Application
Stack	I-Application
"	O
.	O
</s>
<s>
(	O
Formerly	O
the	O
"	O
ELK	B-Application
stack	I-Application
"	O
,	O
short	O
for	O
"	O
Elasticsearch	B-Application
,	O
Logstash	B-Application
,	O
Kibana	B-Application
"	O
.	O
)	O
</s>
<s>
Elasticsearch	B-Application
uses	O
Lucene	B-Language
and	O
tries	O
to	O
make	O
all	O
its	O
features	O
available	O
through	O
the	O
JSON	B-General_Concept
and	O
Java	B-Language
API	I-Language
.	O
</s>
<s>
It	O
supports	O
facetting	O
and	O
percolating	O
(	O
a	O
form	O
of	O
prospective	B-General_Concept
search	I-General_Concept
)	O
,	O
which	O
can	O
be	O
useful	O
for	O
notifying	O
if	O
new	O
documents	O
match	O
for	O
registered	O
queries	O
.	O
</s>
<s>
Another	O
feature	O
,	O
"	O
gateway	O
"	O
,	O
handles	O
the	O
long-term	O
persistence	O
of	O
the	O
index	B-Application
;	O
for	O
example	O
,	O
an	O
index	B-Application
can	O
be	O
recovered	O
from	O
the	O
gateway	O
in	O
the	O
event	O
of	O
a	O
server	O
crash	O
.	O
</s>
<s>
Elasticsearch	B-Application
supports	O
real-time	O
GET	O
requests	O
,	O
which	O
makes	O
it	O
suitable	O
as	O
a	O
NoSQL	B-General_Concept
datastore	O
,	O
but	O
it	O
lacks	O
distributed	B-General_Concept
transactions	I-General_Concept
.	O
</s>
<s>
On	O
20	O
May	O
2019	O
,	O
Elastic	O
made	O
the	O
core	O
security	O
features	O
of	O
the	O
Elastic	B-Application
Stack	I-Application
available	O
free	O
of	O
charge	O
,	O
including	O
TLS	O
for	O
encrypted	O
communications	O
,	O
file	O
and	O
native	O
realm	O
for	O
creating	O
and	O
managing	O
users	O
,	O
and	O
role-based	O
access	O
control	O
for	O
controlling	O
user	O
access	O
to	O
cluster	O
APIs	O
and	O
indexes	O
.	O
</s>
<s>
The	O
corresponding	O
source	O
code	O
is	O
available	O
under	O
the	O
“	O
Elastic	O
License	O
”	O
,	O
a	O
source-available	B-License
license	I-License
.	O
</s>
<s>
In	O
addition	O
,	O
Elasticsearch	B-Application
now	O
offers	O
SIEM	O
and	O
Machine	O
Learning	O
as	O
part	O
of	O
its	O
offered	O
services	O
.	O
</s>
<s>
Developed	O
from	O
the	O
Found	O
acquisition	O
by	O
Elastic	O
in	O
2015	O
,	O
Elastic	O
Cloud	O
is	O
a	O
family	O
of	O
Elasticsearch-powered	O
SaaS	B-Architecture
offerings	O
which	O
include	O
the	O
Elasticsearch	B-Application
Service	O
,	O
as	O
well	O
as	O
Elastic	O
App	O
Search	B-Application
Service	O
,	O
and	O
Elastic	O
Site	O
Search	B-Application
Service	O
which	O
were	O
developed	O
from	O
Elastic	O
's	O
acquisition	O
of	O
Swiftype	B-Application
.	O
</s>
<s>
In	O
late	O
2017	O
,	O
Elastic	O
formed	O
partnerships	O
with	O
Google	B-General_Concept
to	O
offer	O
Elastic	O
Cloud	O
in	O
GCP	O
,	O
and	O
Alibaba	B-General_Concept
to	O
offer	O
Elasticsearch	B-Application
and	O
Kibana	B-Application
in	O
Alibaba	B-General_Concept
Cloud	I-General_Concept
.	O
</s>
<s>
Elasticsearch	B-Application
Service	O
on	O
Elastic	O
Cloud	O
is	O
the	O
official	O
hosted	O
and	O
managed	O
Elasticsearch	B-Application
and	O
Kibana	B-Application
offering	O
from	O
the	O
creators	O
of	O
the	O
project	O
since	O
August	O
2018	O
Elasticsearch	B-Application
Service	O
users	O
can	O
create	O
secure	O
deployments	O
with	O
partners	O
,	O
Google	B-General_Concept
Cloud	I-General_Concept
Platform	I-General_Concept
(	O
GCP	O
)	O
and	O
Alibaba	B-General_Concept
Cloud	I-General_Concept
.	O
</s>
<s>
AWS	B-Application
previously	O
offered	O
Elasticsearch	B-Application
as	O
a	O
managed	O
service	O
beginning	O
2015	O
.	O
</s>
<s>
There	O
are	O
many	O
companies	O
that	O
currently	O
offer	O
managed	O
services	O
,	O
such	O
as	O
Elasticsearch	B-Application
,	O
Instacluster	O
,	O
Opster	O
,	O
and	O
Dattell	O
.	O
</s>
<s>
Most	O
managed	O
services	O
also	O
include	O
support	O
for	O
Kibana	B-Application
.	O
</s>
