<s>
BigCouch	B-General_Concept
is	O
an	O
open-source	B-Application
,	O
highly	O
available	O
,	O
fault-tolerant	B-General_Concept
,	O
clustered	O
&	O
API-compliant	O
version	O
of	O
Apache	B-Application
CouchDB	I-Application
,	O
which	O
was	O
maintained	O
by	O
Cloudant	B-General_Concept
.	O
</s>
<s>
On	O
January	O
5	O
,	O
2012	O
,	O
Cloudant	B-General_Concept
announced	O
they	O
would	O
contribute	O
the	O
BigCouch	B-General_Concept
horizontal	O
scaling	O
framework	O
into	O
the	O
CouchDB	B-Application
project	O
.	O
</s>
<s>
Cloudant	B-General_Concept
announced	O
in	O
June	O
2015	O
that	O
they	O
were	O
no	O
longer	O
supporting	O
BigCouch	B-General_Concept
.	O
</s>
<s>
BigCouch	B-General_Concept
allows	O
users	O
to	O
create	O
clusters	O
of	O
CouchDBs	B-Application
that	O
are	O
distributed	O
over	O
an	O
arbitrary	O
number	O
of	O
servers	O
.	O
</s>
<s>
While	O
it	O
appears	O
to	O
the	O
end-user	O
as	O
one	O
CouchDB	B-Application
instance	O
,	O
it	O
is	O
in	O
fact	O
one	O
or	O
more	O
nodes	O
in	O
an	O
elastic	O
cluster	O
,	O
acting	O
in	O
concert	O
to	O
store	O
and	O
retrieve	O
documents	O
,	O
index	O
and	O
serve	O
views	O
,	O
and	O
serve	O
CouchApps	O
.	O
</s>
<s>
Clusters	O
behave	O
according	O
to	O
concepts	O
outlined	O
in	O
Amazon	O
's	O
Dynamo	B-Application
paper	O
,	O
namely	O
that	O
each	O
node	O
can	O
accept	O
requests	O
,	O
data	O
is	O
placed	O
on	O
partitions	O
based	O
on	O
a	O
consistent	O
hashing	O
algorithm	O
,	O
and	O
quorum	O
protocols	O
are	O
for	O
read/write	O
operations	O
.	O
</s>
<s>
It	O
relies	O
on	O
Erlang	B-Operating_System
and	O
the	O
Open	B-Language
Telecom	I-Language
Platform	I-Language
,	O
despite	O
using	O
its	O
own	O
RPC	O
mechanism	O
over	O
OTP	O
's	O
own	O
"	O
rex	O
"	O
server	O
.	O
</s>
<s>
BigCouch	B-General_Concept
was	O
developed	O
to	O
address	O
a	O
common	O
complaint	O
raised	O
by	O
CouchDB	B-Application
skeptics	O
is	O
that	O
"	O
it	O
does	O
n't	O
scale	O
,	O
"	O
by	O
which	O
they	O
mean	O
it	O
does	O
not	O
scale	O
horizontally	O
across	O
many	O
servers	O
.	O
</s>
<s>
This	O
feature	O
is	O
necessary	O
for	O
CouchDB	B-Application
is	O
to	O
be	O
used	O
to	O
address	O
Big	B-Application
Data	I-Application
problems	O
.	O
</s>
