<s>
Riak	B-General_Concept
(	O
pronounced	O
"	O
ree-ack	O
"	O
)	O
is	O
a	O
distributed	O
NoSQL	B-General_Concept
Key-value	B-Data_Structure
data	I-Data_Structure
store	I-Data_Structure
that	O
offers	O
high	O
availability	O
,	O
fault	B-General_Concept
tolerance	I-General_Concept
,	O
operational	O
simplicity	O
,	O
and	O
scalability	B-Architecture
.	O
</s>
<s>
Riak	B-General_Concept
moved	O
to	O
an	O
entirely	O
open-source	B-Application
project	O
in	O
August	O
2017	O
,	O
with	O
many	O
of	O
the	O
licensed	O
Enterprise	O
Edition	O
features	O
being	O
incorporated	O
.	O
</s>
<s>
Riak	B-General_Concept
implements	O
the	O
principles	O
from	O
Amazon	O
's	O
Dynamo	B-Application
paper	O
with	O
heavy	O
influence	O
from	O
the	O
CAP	B-Operating_System
Theorem	I-Operating_System
.	O
</s>
<s>
Written	O
in	O
Erlang	B-Operating_System
,	O
Riak	B-General_Concept
has	O
fault	B-General_Concept
tolerant	I-General_Concept
data	O
replication	O
and	O
automatic	O
data	O
distribution	O
across	O
the	O
cluster	O
for	O
performance	O
and	O
resilience	O
.	O
</s>
<s>
Riak	B-General_Concept
has	O
a	O
pluggable	O
backend	O
for	O
its	O
core	O
storage	O
,	O
with	O
the	O
default	O
storage	O
backend	O
being	O
Bitcask	B-Application
.	O
</s>
<s>
LevelDB	B-Language
is	O
also	O
supported	O
,	O
with	O
other	O
options	O
(	O
such	O
as	O
the	O
pure-Erlang	O
Leveled	O
)	O
available	O
depending	O
on	O
the	O
version	O
.	O
</s>
<s>
Riak	B-General_Concept
was	O
originally	O
developed	O
by	O
engineers	O
employed	O
by	O
Basho	B-General_Concept
Technologies	I-General_Concept
and	O
maintained	O
by	O
them	O
until	O
2017	O
when	O
the	O
rights	O
were	O
sold	O
to	O
bet365	O
after	O
Basho	B-General_Concept
went	O
into	O
receivership	O
.	O
</s>
<s>
Fault-tolerant	B-General_Concept
availability	O
Riak	B-General_Concept
replicates	O
key/value	B-Data_Structure
stores	I-Data_Structure
across	O
a	O
cluster	O
of	O
nodes	O
with	O
a	O
default	O
n_val	O
of	O
three	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
node	O
outages	O
due	O
to	O
network	B-Algorithm
partition	I-Algorithm
or	O
hardware	O
failures	O
,	O
data	O
can	O
still	O
be	O
written	O
to	O
a	O
neighboring	O
node	O
beyond	O
the	O
initial	O
three	O
,	O
and	O
read-back	O
due	O
to	O
its	O
"	O
masterless	O
"	O
peer-to-peer	O
architecture	O
.	O
</s>
<s>
Queries	O
Riak	B-General_Concept
provides	O
a	O
REST-ful	B-Protocol
API	B-Application
through	O
HTTP	O
and	O
Protocol	B-Protocol
Buffers	I-Protocol
for	O
basic	O
PUT	O
,	O
GET	O
,	O
POST	O
,	O
and	O
DELETE	O
functions	O
.	O
</s>
<s>
More	O
complex	O
queries	O
are	O
also	O
possible	O
,	O
including	O
secondary	O
indexes	O
,	O
search	O
(	O
via	O
Apache	B-Language
Solr	I-Language
)	O
,	O
and	O
MapReduce	B-Operating_System
.	O
</s>
<s>
MapReduce	B-Operating_System
has	O
native	O
support	O
for	O
both	O
JavaScript	B-Language
(	O
using	O
the	O
SpiderMonkey	B-Language
runtime	O
)	O
and	O
Erlang	B-Operating_System
.	O
</s>
<s>
Predictable	O
latency	O
Riak	B-General_Concept
distributes	O
data	O
across	O
nodes	O
with	O
hashing	O
and	O
can	O
provide	O
latency	O
profile	O
,	O
even	O
in	O
the	O
case	O
of	O
multiple	O
node	O
failures	O
.	O
</s>
<s>
Multi-datacenter	O
replication	O
Multi-Datacenter	O
replication	O
(	O
MDC	O
)	O
provides	O
uni-directional	O
and	O
bi-direction	O
replication	O
of	O
data	O
between	O
Riak	B-General_Concept
clusters	O
,	O
whether	O
locally	O
for	O
resilience	O
or	O
globally	O
for	O
faster	O
regional	O
access	O
.	O
</s>
<s>
Bi-directional	O
replication	O
allows	O
for	O
multiple	O
Riak	B-General_Concept
cluster	O
to	O
have	O
eventually	O
consistent	O
data	O
across	O
vast	O
distances	O
.	O
</s>
<s>
All	O
versions	O
of	O
Riak	B-General_Concept
are	O
now	O
entirely	O
open-source	B-Application
and	O
free	O
,	O
and	O
include	O
the	O
extra	O
features	O
that	O
Basho	B-General_Concept
charged	O
license	O
fees	O
for	O
.	O
</s>
<s>
Basho	B-General_Concept
operated	O
a	O
freemium	O
model	O
,	O
wherein	O
they	O
provided	O
free	O
versions	O
of	O
Riak	B-General_Concept
in	O
the	O
form	O
of	O
Riak	B-General_Concept
Core	O
,	O
Riak	B-General_Concept
KV	O
,	O
Riak	B-General_Concept
CS	O
and	O
Riak	B-General_Concept
TS	O
but	O
made	O
their	O
money	O
from	O
licensing	O
more	O
advanced	O
features	O
and	O
SLA-based	O
support	O
.	O
</s>
<s>
riak_core	O
is	O
the	O
distributed	O
systems	O
framework	O
that	O
underpins	O
Riak	B-General_Concept
,	O
forming	O
the	O
foundation	O
for	O
all	O
Riak	B-General_Concept
versions	O
.	O
</s>
<s>
It	O
is	O
being	O
maintained	O
as	O
part	O
of	O
Riak	B-General_Concept
.	O
</s>
<s>
Riak	B-General_Concept
KV	O
is	O
a	O
distributed	O
NoSQL	B-General_Concept
database	O
designed	O
to	O
deliver	O
maximum	O
data	O
availability	O
by	O
distributing	O
data	O
across	O
multiple	O
servers	O
,	O
meaning	O
that	O
if	O
one	O
client	O
can	O
reach	O
one	O
server	O
,	O
it	O
should	O
be	O
able	O
to	O
read	O
and	O
write	O
data.KV	O
went	O
through	O
a	O
few	O
names	O
in	O
it	O
's	O
lifetime	O
,	O
starting	O
as	O
Riak	B-General_Concept
then	O
Riak	B-General_Concept
DS	O
(	O
for	O
Data	B-General_Concept
Store	I-General_Concept
)	O
and	O
finally	O
Riak	B-General_Concept
KV	O
(	O
for	O
Key-Value	O
)	O
.	O
</s>
<s>
When	O
Basho	B-General_Concept
Technologies	I-General_Concept
went	O
into	O
receivership	O
in	O
2017	O
KV	O
development	O
was	O
picked	O
up	O
by	O
the	O
open	O
source	O
community	O
and	O
has	O
continued	O
into	O
2021	O
,	O
with	O
2.2.6	O
released	O
in	O
2018	O
being	O
the	O
first	O
community	O
release	O
of	O
KV	O
.	O
</s>
<s>
This	O
release	O
integrated	O
some	O
features	O
that	O
were	O
originally	O
restricted	O
to	O
Basho	B-General_Concept
's	O
Enterprise	O
versions	O
of	O
Riak	B-General_Concept
.	O
</s>
<s>
The	O
current	O
version	O
of	O
Riak	B-General_Concept
no	O
longer	O
supports	O
some	O
features	O
in	O
the	O
Enterprise	O
edition	O
of	O
Riak	B-General_Concept
,	O
including	O
:	O
</s>
<s>
The	O
following	O
features	O
of	O
Riak	B-General_Concept
KV	O
2.x	O
have	O
been	O
removed	O
by	O
default	O
from	O
the	O
Riak	B-General_Concept
build	O
.	O
</s>
<s>
Originally	O
known	O
as	O
Riak	B-General_Concept
Moss(Riak Multi-tenant Object Storage System - MOSS )	O
but	O
named	O
as	O
Riak	B-General_Concept
CS	O
(	O
Cloud	O
Storage	O
)	O
when	O
released	O
,	O
Riak	B-General_Concept
CS	O
was	O
first	O
publicly	O
released	O
in	O
January	O
2012	O
.	O
</s>
<s>
Riak	B-General_Concept
CS	O
(	O
Cloud	O
Storage	O
)	O
is	O
object	O
storage	O
software	O
built	O
on	O
top	O
of	O
Riak	B-General_Concept
KV	O
,	O
Riak	B-General_Concept
's	O
distributed	O
database	O
.	O
</s>
<s>
Riak	B-General_Concept
CS	O
is	O
designed	O
to	O
provide	O
simple	O
,	O
highly-available	O
,	O
distributed	O
cloud	O
storage	O
at	O
any	O
scale	O
,	O
and	O
can	O
be	O
used	O
to	O
build	O
cloud	O
architectures	O
or	O
as	O
storage	O
infrastructure	O
for	O
heavy-duty	O
applications	O
and	O
services	O
.	O
</s>
<s>
Riak	B-General_Concept
CS	O
also	O
includes	O
an	O
application	O
called	O
Stanchion	O
which	O
is	O
used	O
to	O
manage	O
the	O
serialization	O
of	O
requests	O
.	O
</s>
<s>
This	O
enables	O
Riak	B-General_Concept
CS	O
to	O
manage	O
globally	O
unique	O
entities	O
like	O
users	O
and	O
bucket	O
names	O
.	O
</s>
<s>
Riak	B-General_Concept
CS	O
was	O
briefly	O
rebranded	O
as	O
Riak	B-General_Concept
S2	O
to	O
make	O
it	O
more	O
obviously	O
compatible	O
with	O
Amazon	O
S3	O
but	O
the	O
name	O
did	O
not	O
catch	O
on	O
and	O
it	O
reverted	O
to	O
Riak	B-General_Concept
CS	O
.	O
</s>
<s>
In	O
2021	O
development	O
for	O
Riak	B-General_Concept
CS	O
was	O
resumed	O
with	O
contributions	O
from	O
TI	O
Tokyo	O
.	O
</s>
<s>
Riak	B-General_Concept
TS	O
is	O
an	O
extension	O
to	O
Riak	B-General_Concept
KV	O
optimized	O
for	O
time	O
series	O
data	O
,	O
in	O
that	O
:	O
</s>
<s>
A	O
limited	O
of	O
SQL	O
commands	O
was	O
implemented	O
in	O
Riak	B-General_Concept
TS	O
.	O
</s>
<s>
Riak	B-General_Concept
TS	O
existed	O
as	O
a	O
collection	O
of	O
branches	O
(	O
in	O
separate	O
components	O
of	O
Riak	B-General_Concept
KV	O
such	O
as	O
riak_kv	O
,	O
riak_pb	O
,	O
etc	O
)	O
and	O
not	O
as	O
product	O
with	O
a	O
repository	O
of	O
its	O
own	O
.	O
</s>
<s>
Riak	B-General_Concept
TS	O
was	O
conceived	O
,	O
along	O
with	O
Riak	B-General_Concept
Data	O
Platform	O
project	O
,	O
as	O
an	O
attempt	O
to	O
diversify	O
Basho	B-General_Concept
's	O
product	O
line	O
,	O
an	O
undertaking	O
many	O
insiders	O
regard	O
as	O
misguided	O
and	O
eventually	O
contributing	O
to	O
Basho	B-General_Concept
's	O
demise	O
.	O
</s>
<s>
Riak	B-General_Concept
was	O
originally	O
licensed	O
using	O
a	O
freemium	O
model	O
:	O
open	O
source	O
versions	O
of	O
Riak	B-General_Concept
KV	O
,	O
Riak	B-General_Concept
CS	O
and	O
Riak	B-General_Concept
TS	O
are	O
available	O
,	O
but	O
end	O
users	O
can	O
pay	O
for	O
additional	O
features	O
and	O
support	O
.	O
</s>
<s>
However	O
,	O
since	O
Basho	B-General_Concept
entered	O
receivership	O
and	O
bet365	O
(	O
purchasers	O
of	O
all	O
IP	O
)	O
made	O
all	O
Riak	B-General_Concept
products	O
fully	O
open	O
source	O
,	O
all	O
the	O
premium	O
features	O
are	O
now	O
available	O
in	O
the	O
open	O
source	O
versions	O
.	O
</s>
<s>
Since	O
Basho	B-General_Concept
's	O
demise	O
,	O
community	O
ad-hoc	O
and	O
paid	O
support	O
options	O
have	O
arisen	O
.	O
</s>
<s>
Riak	B-General_Concept
has	O
official	O
drivers	O
for	O
Ruby	B-Language
,	O
Java	B-Language
,	O
Erlang	B-Operating_System
and	O
Python	B-Language
.	O
</s>
<s>
After	O
bet365	O
purchased	O
the	O
Riak	B-General_Concept
IP	O
,	O
the	O
Riak	B-General_Concept
products	O
were	O
made	O
full	O
open	O
source	O
and	O
work	O
to	O
integrate	O
premium	O
features	O
into	O
the	O
open	O
source	O
versions	O
was	O
completed	O
with	O
the	O
2.2.6	O
release	O
.	O
</s>
<s>
Riak	B-General_Concept
was	O
originally	O
written	O
by	O
Andy	O
Gross	O
and	O
others	O
at	O
Basho	B-General_Concept
Technologies	I-General_Concept
to	O
power	O
a	O
web	O
Sales	O
Force	O
Automation	O
application	O
by	O
former	O
engineers	O
and	O
executives	O
from	O
Akamai	B-Application
.	O
</s>
<s>
There	O
was	O
more	O
interest	O
in	O
the	O
datastore	B-General_Concept
technology	O
than	O
the	O
applications	O
built	O
on	O
it	O
,	O
so	O
the	O
company	O
decided	O
to	O
build	O
a	O
business	O
around	O
Riak	B-General_Concept
itself	O
,	O
gaining	O
adoption	O
throughout	O
the	O
Fortune	O
100	O
and	O
becoming	O
a	O
foundation	O
to	O
many	O
of	O
the	O
world	O
's	O
fastest-growing	O
Web-based	O
,	O
mobile	O
and	O
social	O
networking	O
applications	O
,	O
as	O
well	O
as	O
cloud	O
service	O
providers	O
.	O
</s>
<s>
+Riak	O
KV	O
ReleasesVersion	O
!	O
Date	O
ReleasedChanges1.0Inition	O
1.0	O
Release1.1Added	O
Riaknostic	O
,	O
enhanced	O
error	O
logging	O
and	O
reporting	O
,	O
improved	O
resiliency	O
for	O
large	O
clusters	O
,	O
and	O
a	O
new	O
graphical	O
operations	O
and	O
monitoring	O
interface	O
called	O
Riak	B-General_Concept
Control.1.4Added	O
counters	O
,	O
secondary	O
indexing	O
improvements	O
,	O
reduced	O
object	O
storage	O
overhead	O
,	O
handoff	O
progress	O
reporting	O
,	O
and	O
enhancements	O
to	O
MDC	O
replication2.0Added	O
new	O
data	O
types	O
including	O
sets	O
,	O
maps	O
,	O
registers	O
,	O
and	O
flags	O
simplifying	O
application	O
development	O
.	O
</s>
<s>
Strong	O
consistency	O
by	O
bucket	O
,	O
full-text	O
integration	O
with	O
Apache	B-Language
Solr	I-Language
,	O
Security	O
,	O
and	O
reduced	O
replicas	O
for	O
Secondary	O
sites.2.1Added	O
an	O
optimization	O
for	O
many	O
write-heavy	O
workloads	O
–	O
“	O
write	O
once	O
”	O
buckets	O
–	O
buckets	O
whose	O
entries	O
are	O
intended	O
to	O
be	O
written	O
exactly	O
once	O
,	O
and	O
never	O
updated	O
or	O
over-written.2.2added	O
Support	O
for	O
Debian	O
8	O
and	O
Ubuntu	B-Operating_System
16.04	O
,	O
Solr	B-Language
integration	O
improvements.2.2.6The	O
first	O
community	O
release	O
.	O
</s>
<s>
Added	O
support	O
for	O
Multi-Datacentre	O
Replication	O
which	O
was	O
not	O
part	O
of	O
open-source	B-Application
Riak	B-General_Concept
before	O
,	O
added	O
a	O
grow-only	O
set	O
data	O
type	O
,	O
improved	O
data	O
distribution	O
over	O
nodes	O
and	O
cleaned	O
up	O
production	O
test	O
issues.2.9.0Added	O
early	O
support	O
for	O
TicTac	O
Active	O
Anti-Entropy	O
,	O
support	O
for	O
a	O
new	O
Riak	B-General_Concept
specific	O
backend	O
called	O
Leveled.2.9.1Implements	O
next-gen	O
replication	O
,	O
various	O
changes	O
to	O
tombstones	O
and	O
bucket	O
listing.2.9.7Improved	O
Active	O
Anti-Entropy	O
and	O
improved	O
Riak	B-General_Concept
's	O
overall	O
stability.2.9.8Improved	O
leveled	O
functions2.9.9Leveled	O
stability	O
improvements	O
3.0.1Adds	O
support	O
for	O
OTP	O
20	O
,	O
21	O
,	O
22	O
but	O
is	O
not	O
backwards	O
compatible	O
with	O
previous	O
OTP	O
versions.3.0.2Implements	O
backend	O
changes	O
from	O
2.9.8	O
,	O
adds	O
a	O
range_check	O
in	O
the	O
Tictac	O
AAE	O
based	O
full-sync	O
replication3.0.6Adds	O
location-awareness	O
to	O
cluster	O
management	O
,	O
along	O
with	O
bug	O
fixes	O
from	O
3.0.3	O
and	O
3.0.4.3.0.7Reverts	O
Riak	B-General_Concept
erlang	B-Operating_System
runtime	O
system	O
in	O
interactive	O
mode	O
,	O
rather	O
than	O
the	O
embedded	O
mode	O
it	O
was	O
changed	O
to	O
previously	O
.	O
</s>
<s>
+Riak	O
CS	O
ReleasesVersion	O
!	O
Date	O
ReleasedChanges0.0.3The	O
first	O
public	O
release	O
of	O
Riak	B-General_Concept
CS	O
.	O
</s>
<s>
Known	O
as	O
Riak	B-General_Concept
MOSS	O
at	O
the	O
time.0.1.0Bucket-level	O
Access	O
control	O
,	O
user	O
record	O
changes	O
,	O
Stanchion	O
is	O
now	O
required.1.0.0Fixes	O
some	O
process/socket	O
leaks	O
,	O
adds	O
a	O
fix	O
to	O
prevent	O
deadlock	O
conditions	O
,	O
new	O
subsystem	O
for	O
user	O
access	O
&	O
storage	O
usage	O
calculations.1.0.1Fixes	O
a	O
bug	O
that	O
caused	O
requests	O
to	O
hang	O
if	O
a	O
node	O
in	O
the	O
cluster	O
was	O
unavailable1.1.0Updates	O
user	O
creation	O
,	O
configuration	O
options	O
for	O
anonymous	O
users	O
,	O
more	O
user	O
account	O
controls	O
for	O
admins	O
,	O
Garbage	O
collection	O
for	O
deleted	O
objects	O
,	O
improved	O
performance.1.2.0Early	O
support	O
for	O
Multi-datacenter	O
replication	O
,	O
support	O
for	O
riak_test	O
integration	O
,	O
bug	O
fixes.1.2.1Add	O
reduce	O
phase	O
for	O
listing	O
bucket	O
contents	O
to	O
provide	O
backpressure	O
when	O
executing	O
the	O
MapReduce	B-Operating_System
job	O
,	O
Use	O
prereduce	O
during	O
storage	O
calculations	O
,	O
fixed	O
incorrect	O
404	O
error	O
when	O
attempting	O
to	O
list	O
contents	O
of	O
nonexistent	O
bucket.1.2.2Full	O
support	O
for	O
MDC	O
replication	O
,	O
fixed	O
process	O
leaks.1.3.0Support	O
for	O
multi-part	O
file	O
uploads	O
,	O
bucket	O
polices	O
for	O
restricted	O
principles/conditions	O
,	O
range	O
header	O
.	O
</s>
<s>
More	O
administrative	O
command	O
controls	O
,	O
support	O
for	O
FreeBSD	O
,	O
SmartOS	O
and	O
Solaris	B-Application
Packaging.1.3.1Bug	O
fixes1.4.0Early	O
support	O
for	O
Swift	O
API/Keystone	O
Authentication	O
,	O
improved	O
performance	O
,	O
bug	O
fixes.1.5.0Adds	O
a	O
multibag	O
technical	O
preview	O
,	O
new	O
debug	O
command	O
,	O
streamlines	O
commands	O
to	O
new	O
`	O
riak-cs	O
admin`	O
command	O
,	O
improved	O
garbage	O
collection	O
,	O
updated	O
lager	O
,	O
new	O
API	B-Application
-	O
Multiple	O
objects	O
,	O
warning	O
logs	O
for	O
manifests	O
,	O
siblings	O
etc.1.5.1Adds	O
Bucket	O
restrictions	O
,	O
adds	O
sleep	O
interval	O
for	O
manifest	O
updates	O
,	O
updates	O
riak-cs-debug	O
,	O
changes	O
to	O
bucket	O
resolution.1.5.2Improved	O
logging	O
for	O
failures	O
with	O
Riak	B-General_Concept
,	O
Changes	O
to	O
log	O
output	O
for	O
access	O
stats	O
,	O
adds	O
a	O
script	O
for	O
invalid	O
garbage	O
collection	O
manifest	O
repairs.1.5.3Add	O
read_before_last_manifest_write	O
option	O
,	O
Adds	O
configurable	O
timeouts	O
for	O
CS	O
interactions	O
with	O
Riak1.5.4Disable	O
backpressure	O
sleep	O
,	O
Fixes	O
an	O
incorrect	O
path	O
rewrite	O
in	O
S3	O
API2.0.0Updates	O
Riak	B-General_Concept
CS	O
to	O
work	O
with	O
Riak	B-General_Concept
2.0.5	O
,	O
Changes	O
gc_max_workers	O
to	O
gc.max_workers	O
and	O
changed	O
default	O
setting	O
,	O
early	O
support	O
for	O
AWS	O
v4	O
authentication	O
,	O
adds	O
cuttlefish	O
,	O
storage	O
optimisations.2.1.0Final	O
Basho	B-General_Concept
release	O
-	O
Backwards	O
compatible	O
with	O
KV	O
2.0.5	O
,	O
21.1	O
,	O
Adds	O
a	O
large	O
number	O
of	O
new	O
metrics	O
for	O
health	O
monitoring	O
purposes	O
along	O
with	O
storage	O
usage	O
metrics	O
.	O
</s>
<s>
Replaced	O
commands	O
with	O
riak-cs-admin	O
equivalents	O
.	O
</s>
<s>
Garbage	O
collection	O
improvements.2.1.1Compatible	O
with	O
KV	O
2.1.3	O
,	O
2.1.4	O
,	O
2.2.x	O
and	O
2.9.x2.1.2First	O
post-basho	O
release	O
.	O
</s>
<s>
+Riak	O
TS	O
ReleasesVersion	O
!	O
Date	O
ReleasedChanges1.2.0Implements	O
Riak_shell	O
to	O
allow	O
SWQL	O
commands	O
&	O
logging	O
in	O
a	O
single	O
shell	O
in	O
Riak	B-General_Concept
TS	O
.	O
</s>
<s>
Notable	O
users	O
include	O
AT&T	O
,	O
Comcast	O
,	O
GitHub	B-Application
,	O
Best	O
Buy	O
,	O
UK	O
National	O
Health	O
Services	O
(	O
NHS	O
)	O
,	O
The	O
Weather	O
Channel	O
,	O
and	O
Riot	O
Games	O
.	O
</s>
