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Add test-lru.rb to utils.

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This is a program useful to evaluate the Redis LRU algorithm behavior.
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antirez 2014-03-21 09:52:00 +01:00
parent 4d2e8fa189
commit 6972f18cbd
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The test-lru.rb program can be used in order to check the behavior of the
Redis approximated LRU algorithm against the theoretical output of true
LRU algorithm.
In order to use the program you need to recompile Redis setting the define
REDIS_LRU_CLOCK_RESOLUTION to 1, by editing redis.h.
This allows to execute the program in a fast way since the 1 ms resolution
is enough for all the objects to have a different enough time stamp during
the test.
The program is executed like this:
ruby test-lru.rb > /tmp/lru.html

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utils/lru/test-lru.rb Normal file
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require 'rubygems'
require 'redis'
r = Redis.new
r.config("SET","maxmemory","2000000")
r.config("SET","maxmemory-policy","allkeys-lru")
r.config("SET","maxmemory-samples",5)
r.config("RESETSTAT")
r.flushall
puts <<EOF
<html>
<body>
<style>
.box {
width:5px;
height:5px;
float:left;
margin: 1px;
}
.old {
border: 1px black solid;
}
.new {
border: 1px green solid;
}
.ex {
background-color: #666;
}
</style>
<pre>
EOF
# Fill
oldsize = r.dbsize
id = 0
while true
id += 1
r.set(id,"foo")
newsize = r.dbsize
break if newsize == oldsize
oldsize = newsize
end
inserted = r.dbsize
first_set_max_id = id
puts "#{r.dbsize} keys inserted"
# Access keys sequencially
puts "Access keys sequencially"
(1..first_set_max_id).each{|id|
r.get(id)
# sleep 0.001
}
# Insert more 50% keys. We expect that the new keys
half = inserted/2
puts "Insert enough keys to evict half the keys we inserted"
add = 0
while true
add += 1
id += 1
r.set(id,"foo")
break if r.info['evicted_keys'].to_i >= half
end
puts "#{add} additional keys added."
puts "#{r.dbsize} keys in DB"
# Check if evicted keys respect LRU
# We consider errors from 1 to N progressively more serious as they violate
# more the access pattern.
errors = 0
e = 1
edecr = 1.0/(first_set_max_id/2)
(1..(first_set_max_id/2)).each{|id|
e -= edecr if e > 0
e = 0 if e < 0
if r.exists(id)
errors += e
end
}
puts "#{errors} errors!"
puts "</pre>"
# Generate the graphical representation
(1..id).each{|id|
# Mark first set and added items in a different way.
c = "box"
if id <= first_set_max_id
c << " old"
else
c << " new"
end
# Add class if exists
c << " ex" if r.exists(id)
puts "<div class=\"#{c}\"></div>"
}
# Close HTML page
puts <<EOF
</body>
</html>
EOF