<s>
Amazon	B-General_Concept
Elastic	I-General_Concept
Compute	I-General_Concept
Cloud	I-General_Concept
(	O
EC2	O
)	O
is	O
a	O
part	O
of	O
com	O
's	O
cloud-computing	B-Architecture
platform	O
,	O
Amazon	B-Application
Web	I-Application
Services	I-Application
(	O
AWS	B-Application
)	O
,	O
that	O
allows	O
users	O
to	O
rent	O
virtual	B-Architecture
computers	I-Architecture
on	O
which	O
to	O
run	O
their	O
own	O
computer	O
applications	O
.	O
</s>
<s>
EC2	O
encourages	O
scalable	O
deployment	O
of	O
applications	O
by	O
providing	O
a	O
web	O
service	O
through	O
which	O
a	O
user	O
can	O
boot	O
an	O
Amazon	B-Application
Machine	I-Application
Image	I-Application
(	O
AMI	O
)	O
to	O
configure	O
a	O
virtual	B-Architecture
machine	I-Architecture
,	O
which	O
Amazon	B-Application
calls	O
an	O
"	O
instance	O
"	O
,	O
containing	O
any	O
software	O
desired	O
.	O
</s>
<s>
A	O
user	O
can	O
create	O
,	O
launch	O
,	O
and	O
terminate	O
server-instances	O
as	O
needed	O
,	O
paying	O
by	O
the	O
second	O
for	O
active	O
servershence	O
the	O
term	O
"	O
elastic	O
"	O
.	O
</s>
<s>
EC2	O
provides	O
users	O
with	O
control	O
over	O
the	O
geographical	O
location	O
of	O
instances	O
that	O
allows	O
for	O
latency	B-Protocol
optimization	O
and	O
high	O
levels	O
of	O
redundancy	O
.	O
</s>
<s>
In	O
November	O
2010	O
,	O
Amazon	B-Application
switched	O
its	O
own	O
retail	O
website	O
platform	O
to	O
EC2	O
and	O
AWS	B-Application
.	O
</s>
<s>
Amazon	B-Application
announced	O
a	O
limited	O
public	O
beta	O
test	O
of	O
EC2	O
on	O
August	O
25	O
,	O
2006	O
,	O
offering	O
access	O
on	O
a	O
first-come	O
,	O
first-served	O
basis	O
.	O
</s>
<s>
Amazon	B-Application
added	O
two	O
new	O
instance	O
types	O
(	O
Large	O
and	O
Extra-Large	O
)	O
on	O
October	O
16	O
,	O
2007	O
.	O
</s>
<s>
Amazon	B-Application
added	O
three	O
new	O
features	O
on	O
March	O
27	O
,	O
2008	O
,	O
static	O
IP	O
addresses	O
,	O
availability	O
zones	O
,	O
and	O
user	O
selectable	O
kernels	B-Operating_System
.	O
</s>
<s>
Amazon	B-General_Concept
EC2	I-General_Concept
went	O
into	O
full	O
production	O
when	O
it	O
dropped	O
the	O
beta	O
label	O
on	O
October	O
23	O
,	O
2008	O
.	O
</s>
<s>
On	O
the	O
same	O
day	O
,	O
Amazon	B-Application
announced	O
the	O
following	O
features	O
:	O
</s>
<s>
Microsoft	B-Application
Windows	I-Application
in	O
beta	O
form	O
on	O
EC2	O
,	O
</s>
<s>
Microsoft	B-Application
SQL	I-Application
Server	I-Application
in	O
beta	O
form	O
on	O
EC2	O
,	O
</s>
<s>
plans	O
for	O
load	B-Application
balancing	I-Application
,	O
autoscaling	B-General_Concept
,	O
and	O
cloud	O
monitoring	O
services	O
.	O
</s>
<s>
Amazon	B-General_Concept
EC2	I-General_Concept
was	O
developed	O
mostly	O
by	O
a	O
team	O
in	O
Cape	O
Town	O
,	O
South	O
Africa	O
led	O
by	O
Chris	O
Pinkham	O
.	O
</s>
<s>
Initially	O
,	O
EC2	O
used	O
Xen	B-Operating_System
virtualization	O
exclusively	O
.	O
</s>
<s>
However	O
,	O
on	O
November	O
6	O
,	O
2017	O
,	O
Amazon	B-Application
announced	O
the	O
new	O
C5	O
family	O
of	O
instances	O
that	O
were	O
based	O
on	O
a	O
custom	O
architecture	O
around	O
the	O
KVM	B-Application
hypervisor	I-Application
,	O
called	O
Nitro	O
.	O
</s>
<s>
Each	O
virtual	B-Architecture
machine	I-Architecture
,	O
called	O
an	O
"	O
instance	O
"	O
,	O
functions	O
as	O
a	O
virtual	B-General_Concept
private	I-General_Concept
server	I-General_Concept
.	O
</s>
<s>
Amazon	B-Application
sizes	O
instances	O
based	O
on	O
"	O
Elastic	B-General_Concept
Compute	I-General_Concept
Units	I-General_Concept
"	O
.	O
</s>
<s>
The	O
performance	O
of	O
otherwise	O
identical	O
virtual	B-Architecture
machines	I-Architecture
may	O
vary	O
.	O
</s>
<s>
On	O
November	O
28	O
,	O
2017	O
,	O
AWS	B-Application
announced	O
a	O
bare-metal	O
instance	O
type	O
offering	O
marking	O
a	O
remarkable	O
departure	O
from	O
exclusively	O
offering	O
virtualized	O
instance	O
types	O
.	O
</s>
<s>
,	O
Amazon	B-Application
charged	O
about	O
$0.0058	O
per	O
hour	O
(	O
$4.176	O
per	O
month	O
)	O
for	O
the	O
smallest	O
"	O
Nano	O
Instance	O
"	O
(	O
t2.nano	O
)	O
virtual	B-Architecture
machine	I-Architecture
running	O
Linux	B-Operating_System
or	O
Windows	O
.	O
</s>
<s>
The	O
data	O
transfer	O
charge	O
ranges	O
from	O
free	O
to	O
$0.12	O
per	O
gigabyte	O
,	O
depending	O
on	O
the	O
direction	O
and	O
monthly	O
volume	O
(	O
inbound	O
data	O
transfer	O
is	O
free	O
on	O
all	O
AWS	B-Application
services	O
)	O
.	O
</s>
<s>
EC2	O
costs	O
can	O
be	O
analyzes	O
using	O
the	O
Amazon	B-Application
Cost	O
and	O
Usage	O
Report	O
.	O
</s>
<s>
Amazon	B-Application
offered	O
a	O
bundle	O
of	O
free	O
resource	O
credits	O
to	O
new	O
account	O
holders	O
.	O
</s>
<s>
The	O
credits	O
are	O
designed	O
to	O
run	O
a	O
"	O
micro	O
"	O
sized	O
server	B-Application
,	O
storage	O
(	O
EBS	O
)	O
,	O
and	O
bandwidth	O
for	O
one	O
year	O
.	O
</s>
<s>
The	O
corresponding	O
hourly	O
rate	O
charged	O
by	O
Amazon	B-Application
to	O
operate	O
the	O
instance	O
is	O
35	O
to	O
75%	O
lower	O
than	O
the	O
rate	O
charged	O
for	O
on-demand	O
instances	O
.	O
</s>
<s>
In	O
September	O
2016	O
,	O
AWS	B-Application
announced	O
several	O
enhancements	O
to	O
Reserved	O
instances	O
,	O
introducing	O
a	O
new	O
feature	O
called	O
scope	O
and	O
a	O
new	O
reservation	O
type	O
called	O
a	O
Convertible	O
.	O
</s>
<s>
Amazon	B-General_Concept
EC2	I-General_Concept
Spot	O
instances	O
are	O
spare	O
compute	O
capacity	O
in	O
the	O
AWS	B-Application
cloud	O
available	O
at	O
up	O
to	O
90%	O
discount	O
compared	O
to	O
On-Demand	O
prices	O
.	O
</s>
<s>
As	O
a	O
trade-off	O
,	O
AWS	B-Application
offers	O
no	O
SLA	O
on	O
these	O
instances	O
and	O
customers	O
take	O
the	O
risk	O
that	O
it	O
can	O
be	O
interrupted	O
with	O
only	O
two	O
minutes	O
of	O
notification	O
when	O
Amazon	B-Application
needs	O
the	O
capacity	O
back	O
.	O
</s>
<s>
In	O
November	O
2019	O
,	O
Amazon	B-Application
announced	O
Savings	O
Plans	O
.	O
</s>
<s>
AWS	B-Application
uses	O
the	O
Cost	O
Explorer	O
to	O
automatically	O
calculate	O
recommendations	O
for	O
the	O
commitments	O
you	O
should	O
make	O
how	O
that	O
commitment	O
will	O
look	O
like	O
as	O
a	O
monthly	O
charge	O
on	O
your	O
AWS	B-Application
bill	O
.	O
</s>
<s>
AWS	B-Application
Savings	O
Plans	O
are	O
purchased	O
based	O
on	O
hourly	O
spend	O
commitment	O
.	O
</s>
<s>
When	O
it	O
launched	O
in	O
August	O
2006	O
,	O
the	O
EC2	O
service	O
offered	O
Linux	B-Operating_System
and	O
later	O
Sun	O
Microsystems	O
 '	O
OpenSolaris	B-Operating_System
and	O
Solaris	B-Application
Express	I-Application
Community	I-Application
Edition	I-Application
.	O
</s>
<s>
In	O
October	O
2008	O
,	O
EC2	O
added	O
the	O
Windows	B-Application
Server	I-Application
2003	I-Application
and	O
Windows	B-Device
Server	I-Device
2008	I-Device
operating	B-General_Concept
systems	I-General_Concept
to	O
the	O
list	O
of	O
available	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
In	O
March	O
2011	O
,	O
NetBSD	B-Device
AMIs	O
became	O
available	O
.	O
</s>
<s>
In	O
November	O
2012	O
,	O
Windows	B-Device
Server	I-Device
2012	I-Device
support	O
was	O
added	O
.	O
</s>
<s>
Since	O
2006	O
,	O
Colin	O
Percival	O
,	O
a	O
FreeBSD	B-Operating_System
developer	O
and	O
Security	O
Officer	O
,	O
solicited	O
Amazon	B-Application
to	O
add	O
FreeBSD	B-Operating_System
.	O
</s>
<s>
In	O
November	O
2012	O
,	O
Amazon	B-Application
officially	O
supported	O
running	O
FreeBSD	B-Operating_System
in	O
EC2	O
.	O
</s>
<s>
The	O
FreeBSD/EC2	O
platform	O
is	O
maintained	O
by	O
Percival	O
who	O
also	O
developed	O
the	O
secure	O
deduplicating	B-General_Concept
Amazon	O
S3-cloud	O
based	O
backup	O
service	O
Tarsnap	B-General_Concept
.	O
</s>
<s>
Amazon	B-Application
has	O
their	O
own	O
Linux	B-Operating_System
distribution	O
based	O
on	O
Fedora	O
and	O
Red	O
Hat	O
Enterprise	O
Linux	B-Operating_System
as	O
a	O
low	O
cost	O
offering	O
known	O
as	O
the	O
Amazon	B-Application
Linux	I-Application
AMI	I-Application
.	O
</s>
<s>
On	O
November	O
30	O
,	O
2020	O
,	O
Amazon	B-Application
announced	O
that	O
it	O
would	O
be	O
adding	O
macOS	B-Application
to	O
the	O
EC2	O
service	O
.	O
</s>
<s>
Initial	O
support	O
was	O
announced	O
for	O
macOS	B-Device
Mojave	I-Device
and	O
macOS	B-Device
Catalina	I-Device
running	O
on	O
Mac	B-Device
mini	I-Device
.	O
</s>
<s>
The	O
Amazon	B-Application
Elastic	O
Block	O
Store	O
(	O
EBS	O
)	O
provides	O
raw	O
block	O
devices	O
that	O
can	O
be	O
attached	O
to	O
Amazon	B-General_Concept
EC2	I-General_Concept
instances	O
.	O
</s>
<s>
In	O
a	O
typical	O
use	O
case	O
,	O
this	O
would	O
include	O
formatting	O
the	O
device	O
with	O
a	O
filesystem	B-Application
and	O
mounting	B-Application
it	O
.	O
</s>
<s>
EBS	O
was	O
introduced	O
to	O
the	O
general	O
public	O
by	O
Amazon	B-Application
in	O
August	O
2008	O
.	O
</s>
<s>
EBS	O
volumes	O
provide	O
persistent	O
storage	O
independent	O
of	O
the	O
lifetime	O
of	O
the	O
EC2	O
instance	O
,	O
and	O
act	O
much	O
like	O
hard	O
drives	O
on	O
a	O
real	O
server	B-Application
.	O
</s>
<s>
More	O
accurately	O
,	O
they	O
appear	O
as	O
block	O
devices	O
to	O
the	O
operating	B-General_Concept
system	I-General_Concept
that	O
are	O
backed	O
by	O
Amazon	B-Application
's	O
disk	O
arrays	O
.	O
</s>
<s>
In	O
the	O
most	O
common	O
case	O
,	O
a	O
file	B-Application
system	I-Application
is	O
loaded	O
and	O
the	O
volume	O
acts	O
as	O
a	O
hard	O
drive	O
.	O
</s>
<s>
Simple	B-General_Concept
Storage	I-General_Concept
Service	I-General_Concept
(	O
S3	O
)	O
is	O
a	O
storage	O
system	O
in	O
which	O
data	O
is	O
accessible	O
to	O
EC2	O
instances	O
,	O
or	O
directly	O
over	O
the	O
network	O
to	O
suitably	O
authenticated	O
callers	O
(	O
all	O
communication	O
is	O
over	O
HTTP	O
)	O
.	O
</s>
<s>
Amazon	B-Application
does	O
not	O
charge	O
for	O
the	O
bandwidth	O
for	O
communications	O
between	O
EC2	O
instances	O
and	O
S3	O
storage	O
"	O
in	O
the	O
same	O
region.	O
"	O
</s>
<s>
Accessing	O
S3	O
data	O
stored	O
in	O
a	O
different	O
region	O
(	O
for	O
example	O
,	O
data	O
stored	O
in	O
Europe	O
from	O
a	O
US	O
East	O
Coast	O
EC2	O
instance	O
)	O
will	O
be	O
billed	O
at	O
Amazon	B-Application
's	O
normal	O
rates	O
.	O
</s>
<s>
For	O
example	O
,	O
Apache	B-Application
Hadoop	I-Application
supports	O
a	O
special	O
s3	O
:	O
filesystem	B-Application
to	O
support	O
reading	O
from	O
and	O
writing	O
to	O
S3	O
storage	O
during	O
a	O
MapReduce	B-Operating_System
job	O
.	O
</s>
<s>
There	O
are	O
also	O
S3	O
filesystems	B-Application
for	O
Linux	B-Operating_System
,	O
which	O
mount	O
a	O
remote	O
S3	O
filestore	O
on	O
an	O
EC2	O
image	O
,	O
as	O
if	O
it	O
were	O
local	O
storage	O
.	O
</s>
<s>
As	O
S3	O
is	O
not	O
a	O
full	O
POSIX	O
filesystem	B-Application
,	O
things	O
may	O
not	O
behave	O
the	O
same	O
as	O
on	O
a	O
local	O
disk	O
(	O
e.g.	O
,	O
no	O
locking	O
support	O
)	O
.	O
</s>
<s>
Amazon	B-Application
's	O
elastic	B-General_Concept
IP	I-General_Concept
address	I-General_Concept
feature	O
is	O
similar	O
to	O
static	O
IP	O
address	O
in	O
traditional	O
data	O
centers	O
,	O
with	O
one	O
key	O
difference	O
.	O
</s>
<s>
A	O
user	O
can	O
programmatically	O
map	O
an	O
elastic	B-General_Concept
IP	I-General_Concept
address	I-General_Concept
to	O
any	O
virtual	B-Architecture
machine	I-Architecture
instance	O
without	O
a	O
network	O
administrator	O
's	O
help	O
and	O
without	O
having	O
to	O
wait	O
for	O
DNS	O
to	O
propagate	O
the	O
binding	O
.	O
</s>
<s>
In	O
this	O
sense	O
an	O
Elastic	B-General_Concept
IP	I-General_Concept
Address	I-General_Concept
belongs	O
to	O
the	O
account	O
and	O
not	O
to	O
a	O
virtual	B-Architecture
machine	I-Architecture
instance	O
.	O
</s>
<s>
Amazon	B-Application
CloudWatch	O
is	O
a	O
web	O
service	O
that	O
provides	O
real-time	O
monitoring	O
to	O
Amazon	B-Application
's	O
EC2	O
customers	O
on	O
their	O
resource	O
utilization	O
such	O
as	O
CPU	O
,	O
disk	O
,	O
network	O
and	O
replica	O
lag	O
for	O
RDS	O
Database	O
replicas	O
.	O
</s>
<s>
Since	O
December	O
2017	O
Amazon	B-Application
provides	O
a	O
CloudWatch	O
Agent	O
for	O
Windows	O
and	O
Linux	B-Application
operating	I-Application
systems	I-Application
included	O
disk	O
and	O
previously	O
not	O
available	O
memory	O
information	O
,	O
previously	O
Amazon	B-Application
provided	O
example	O
scripts	O
for	O
Linux	B-Operating_System
instances	O
to	O
collect	O
OS	O
information	O
.	O
</s>
<s>
The	O
data	O
is	O
aggregated	O
and	O
provided	O
through	O
AWS	B-Application
management	O
console	O
.	O
</s>
<s>
Amazon	B-Application
provides	O
an	O
API	O
which	O
allows	O
clients	O
to	O
operate	O
on	O
CloudWatch	O
alarms	O
.	O
</s>
<s>
The	O
metrics	O
collected	O
by	O
Amazon	B-Application
CloudWatch	O
enables	O
the	O
auto-scaling	B-General_Concept
feature	O
to	O
dynamically	O
add	O
or	O
remove	O
EC2	O
instances	O
.	O
</s>
<s>
Since	O
May	O
2011	O
,	O
Amazon	B-Application
CloudWatch	O
accepts	O
custom	O
metrics	O
that	O
can	O
be	O
submitted	O
programmatically	O
via	O
Web	O
Services	O
API	O
and	O
then	O
monitored	O
the	O
same	O
way	O
as	O
all	O
other	O
internal	O
metrics	O
,	O
including	O
setting	O
up	O
the	O
alarms	O
for	O
them	O
,	O
and	O
since	O
July	O
2014	O
Cloudwatch	O
Logs	O
service	O
is	O
also	O
available	O
.	O
</s>
<s>
Basic	O
Amazon	B-Application
CloudWatch	O
is	O
included	O
in	O
Amazon	B-Application
Free	O
Tier	O
service	O
.	O
</s>
<s>
Amazon	B-Application
's	O
auto-scaling	B-General_Concept
feature	O
of	O
EC2	O
allows	O
it	O
to	O
automatically	O
adapt	O
computing	O
capacity	O
to	O
site	O
traffic	O
.	O
</s>
<s>
CPU	O
utilization	O
thresholds	O
)	O
auto	B-General_Concept
scaling	I-General_Concept
mechanisms	O
are	O
easy	O
to	O
use	O
and	O
efficient	O
for	O
simple	O
applications	O
.	O
</s>
<s>
An	O
example	O
of	O
this	O
pricing	O
would	O
be	O
$0.096	O
per	O
hour	O
for	O
a	O
Linux	B-Operating_System
,	O
m5.large	O
,	O
EC2	O
instance	O
in	O
the	O
us-east-1	O
region	O
.	O
</s>
<s>
Pricing	O
will	O
vary	O
based	O
on	O
the	O
instance	O
type	O
,	O
region	O
,	O
and	O
operating	B-General_Concept
system	I-General_Concept
of	O
the	O
instance	O
.	O
</s>
<s>
Amazon	B-General_Concept
EC2	I-General_Concept
price	O
varies	O
from	O
$2.5	O
per	O
month	O
for	O
"	O
nano	O
"	O
instance	O
with	O
1	O
vCPU	O
and	O
0.5	O
GB	O
RAM	O
on	O
board	O
to	O
"	O
xlarge	O
"	O
type	O
of	O
instances	O
with	O
32	O
vCPU	O
and	O
488	O
GB	O
RAM	O
billed	O
up	O
to	O
$3997.19	O
per	O
month	O
.	O
</s>
<s>
The	O
charts	O
above	O
show	O
how	O
Amazon	B-General_Concept
EC2	I-General_Concept
pricing	O
is	O
compared	O
to	O
similar	O
Cloud	B-Architecture
Computing	I-Architecture
services	O
:	O
Microsoft	B-Application
Azure	I-Application
,	O
Google	B-General_Concept
Cloud	I-General_Concept
Platform	I-General_Concept
,	O
Kamatera	O
,	O
and	O
Vultr	O
.	O
</s>
<s>
To	O
make	O
EC2	O
more	O
fault-tolerant	B-General_Concept
,	O
Amazon	B-Application
engineered	O
Availability	O
Zones	O
that	O
are	O
designed	O
to	O
be	O
insulated	O
from	O
failures	O
in	O
other	O
availability	O
zones	O
.	O
</s>
<s>
EC2	O
provides	O
users	O
with	O
control	O
over	O
the	O
geographical	O
location	O
of	O
instances	O
that	O
allows	O
for	O
latency	B-Protocol
optimization	O
and	O
high	O
levels	O
of	O
redundancy	O
.	O
</s>
<s>
For	O
example	O
,	O
to	O
minimize	O
downtime	O
,	O
a	O
user	O
can	O
set	O
up	O
server	B-Application
instances	O
in	O
multiple	O
zones	O
that	O
are	O
insulated	O
from	O
each	O
other	O
for	O
most	O
causes	O
of	O
failure	O
such	O
that	O
one	O
backs	O
up	O
the	O
other	O
.	O
</s>
<s>
Higher-availability	O
database	O
services	O
,	O
like	O
Amazon	B-Application
Relational	O
Database	O
Service	O
run	O
separately	O
from	O
EC2	O
instances	O
.	O
</s>
<s>
In	O
early	O
July	O
2008	O
,	O
the	O
anti-spam	O
organizations	O
Outblaze	O
and	O
Spamhaus.org	O
began	O
blocking	O
Amazon	B-Application
's	O
EC2	O
address	O
pool	O
due	O
to	O
problems	O
with	O
the	O
distribution	O
of	O
spam	O
and	O
malware	O
.	O
</s>
<s>
On	O
December	O
1	O
,	O
2010	O
,	O
Amazon	B-Application
pulled	O
its	O
service	O
to	O
WikiLeaks	O
after	O
coming	O
under	O
political	O
pressure	O
in	O
the	O
US	O
.	O
</s>
<s>
The	O
Internet	O
group	O
Anonymous	O
attempted	O
to	O
attack	O
EC2	O
in	O
revenge	O
;	O
however	O
,	O
Amazon	B-Application
was	O
not	O
affected	O
by	O
the	O
attack	O
.	O
</s>
<s>
Amazon	B-Application
's	O
websites	O
were	O
temporarily	O
offline	O
on	O
December	O
12	O
,	O
2010	O
,	O
although	O
it	O
was	O
initially	O
unclear	O
if	O
this	O
was	O
due	O
to	O
attacks	O
or	O
a	O
hardware	O
failure	O
.	O
</s>
<s>
An	O
Amazon	B-Application
official	O
later	O
stated	O
that	O
it	O
was	O
due	O
to	O
a	O
hardware	O
failure	O
.	O
</s>
<s>
Shortly	O
before	O
5am	O
ET	O
on	O
April	O
21	O
,	O
2011	O
,	O
an	O
outage	O
started	O
at	O
EC2	O
's	O
Northern	O
Virginia	O
data	O
center	O
that	O
brought	O
down	O
several	O
websites	O
,	O
including	O
Foursquare	B-Application
,	O
Springpad	B-Application
,	O
Reddit	B-Application
,	O
Quora	O
,	O
and	O
Hootsuite	B-Application
.	O
</s>
<s>
Specifically	O
,	O
attempts	O
to	O
use	O
Amazon	B-Application
's	O
elastic-disk	O
and	O
database	O
services	O
hung	O
,	O
failed	O
,	O
or	O
were	O
slow	O
.	O
</s>
<s>
Service	O
was	O
restored	O
to	O
some	O
parts	O
of	O
the	O
datacenter	O
(	O
three	O
of	O
four	O
"	O
availability	O
zones	O
"	O
in	O
Amazon	B-Application
's	O
terms	O
)	O
by	O
late	O
afternoon	O
Eastern	O
time	O
that	O
day	O
;	O
problems	O
for	O
at	O
least	O
some	O
customers	O
were	O
continuing	O
as	O
of	O
April	O
25	O
.	O
</s>
<s>
0.07	O
%	O
of	O
EBS	O
volumes	O
in	O
one	O
zone	O
have	O
also	O
been	O
lost	O
;	O
EBS	O
failures	O
were	O
a	O
part	O
of	O
normal	O
operation	O
even	O
before	O
this	O
outage	O
and	O
were	O
a	O
risk	O
documented	O
by	O
Amazon	B-Application
,	O
though	O
the	O
number	O
of	O
failures	O
and	O
the	O
number	O
of	O
simultaneous	O
failures	O
may	O
find	O
some	O
EC2	O
users	O
unprepared	O
.	O
</s>
<s>
On	O
Sunday	O
August	O
6	O
,	O
2011	O
,	O
Amazon	B-Application
suffered	O
a	O
power	O
outage	O
in	O
one	O
of	O
their	O
Ireland	O
availability	O
zones	O
.	O
</s>
<s>
The	O
power	O
outage	O
raised	O
multiple	O
questions	O
regarding	O
Amazon	B-Application
's	O
EBS	O
infrastructure	O
,	O
which	O
caused	O
several	O
bugs	O
in	O
their	O
software	O
to	O
be	O
exposed	O
.	O
</s>
<s>
August	O
8	O
,	O
2011	O
,	O
saw	O
another	O
network	O
connectivity	O
outage	O
of	O
Amazon	B-Application
's	O
Northern	O
Virginia	O
datacenter	O
,	O
knocking	O
out	O
the	O
likes	O
of	O
Reddit	B-Application
,	O
Quora	O
,	O
Netflix	O
and	O
FourSquare	B-Application
.	O
</s>
<s>
Edmodo	O
,	O
Airbnb	O
,	O
Flipboard	O
,	O
Reddit	B-Application
,	O
and	O
other	O
customers	O
were	O
affected	O
.	O
</s>
<s>
Anonymous	O
claimed	O
responsibility	O
,	O
but	O
Amazon	B-Application
denied	O
this	O
assertion	O
.	O
</s>
