<s>
The	O
Berkeley	B-Operating_System
algorithm	I-Operating_System
is	O
a	O
method	O
of	O
clock	O
synchronisation	O
in	O
distributed	B-Architecture
computing	I-Architecture
which	O
assumes	O
no	O
machine	O
has	O
an	O
accurate	O
time	O
source	O
.	O
</s>
<s>
Like	O
Cristian	B-Operating_System
's	I-Operating_System
algorithm	I-Operating_System
,	O
it	O
is	O
intended	O
for	O
use	O
within	O
intranets	B-General_Concept
.	O
</s>
<s>
Unlike	O
Cristian	B-Operating_System
's	I-Operating_System
algorithm	I-Operating_System
,	O
the	O
server	O
process	O
in	O
the	O
Berkeley	B-Operating_System
algorithm	I-Operating_System
,	O
called	O
the	O
leader	O
,	O
periodically	O
polls	O
other	O
follower	O
processes	O
.	O
</s>
<s>
A	O
leader	O
is	O
chosen	O
via	O
an	O
election	B-Operating_System
process	I-Operating_System
such	O
as	O
Chang	B-Operating_System
and	I-Operating_System
Roberts	I-Operating_System
algorithm	I-Operating_System
.	O
</s>
<s>
The	O
leader	O
polls	O
the	O
followers	O
who	O
reply	O
with	O
their	O
time	O
in	O
a	O
similar	O
way	O
to	O
Cristian	B-Operating_System
's	I-Operating_System
algorithm	I-Operating_System
.	O
</s>
<s>
Doing	O
so	O
would	O
break	O
the	O
property	O
of	O
monotonic	O
time	O
,	O
which	O
is	O
a	O
fundamental	O
assumption	O
in	O
certain	O
algorithms	O
in	O
the	O
system	O
itself	O
or	O
in	O
programs	O
such	O
as	O
make	B-Application
.	O
</s>
