<s>
Implementations	O
of	O
the	O
Circuit	B-Language
Breaker	I-Language
Design	I-Language
Pattern	I-Language
need	O
to	O
retain	O
the	O
state	O
of	O
the	O
connection	O
over	O
a	O
series	O
of	O
requests	O
.	O
</s>
<s>
One	O
way	O
this	O
can	O
be	O
achieved	O
is	O
asynchronously	B-Operating_System
.	O
</s>
<s>
a	O
network	O
cache	O
such	O
as	O
Memcached	B-Application
or	O
Redis	B-Operating_System
,	O
or	O
local	O
cache	O
(	O
disk	O
or	O
memory	O
based	O
)	O
to	O
record	O
the	O
availability	O
of	O
what	O
is	O
,	O
to	O
the	O
application	O
,	O
an	O
external	O
service	O
.	O
</s>
<s>
The	O
following	O
script	O
could	O
be	O
run	O
on	O
a	O
set	O
interval	O
through	O
crontab	B-General_Concept
.	O
</s>
