Commit 32a54943 authored by antirez's avatar antirez
Browse files

LRU: test-lru.rb improved in different ways.

1. Scan keys with pause to account for actual LRU precision.
2. Test cross-DB with 100 keys allocated in DB1.
3. Output results that don't fluctuate depending on number of keys.
4. Output results in percentage to make more sense.
5. Save file instead of outputting to STDOUT.
6. Support running multiple times with average of outputs.
7. Label each square (DIV) with its ID as HTML title.
parent eee878cb
...@@ -3,11 +3,17 @@ Redis approximated LRU algorithm against the theoretical output of true ...@@ -3,11 +3,17 @@ Redis approximated LRU algorithm against the theoretical output of true
LRU algorithm. LRU algorithm.
In order to use the program you need to recompile Redis setting the define In order to use the program you need to recompile Redis setting the define
REDIS_LRU_CLOCK_RESOLUTION to 1, by editing redis.h. REDIS_LRU_CLOCK_RESOLUTION to 1, by editing the file server.h.
This allows to execute the program in a fast way since the 1 ms resolution 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 is enough for all the objects to have a different enough time stamp during
the test. the test.
The program is executed like this: The program is executed like this:
ruby test-lru.rb > /tmp/lru.html ruby test-lru.rb /tmp/lru.html
You can optionally specify a number of times to run, so that the program
will output averages of different runs, by adding an additional argument.
For instance in order to run the test 10 times use:
ruby test-lru.rb /tmp/lru.html 10
require 'rubygems' require 'rubygems'
require 'redis' require 'redis'
r = Redis.new $runs = []; # Remember the error rate of each run for average purposes.
r.config("SET","maxmemory","2000000")
r.config("SET","maxmemory-policy","allkeys-lru") def testit(filename)
r.config("SET","maxmemory-samples",5) r = Redis.new
r.config("RESETSTAT") r.config("SET","maxmemory","2000000")
r.flushall r.config("SET","maxmemory-policy","allkeys-lru")
r.config("SET","maxmemory-samples",10)
puts <<EOF r.config("RESETSTAT")
<html> r.flushall
<body>
<style> html = ""
.box { html << <<EOF
<html>
<body>
<style>
.box {
width:5px; width:5px;
height:5px; height:5px;
float:left; float:left;
margin: 1px; margin: 1px;
} }
.old { .old {
border: 1px black solid; border: 1px black solid;
} }
.new { .new {
border: 1px green solid; border: 1px green solid;
} }
.otherdb {
border: 1px red solid;
}
.ex { .ex {
background-color: #666; background-color: #666;
} }
</style> </style>
<pre> <pre>
EOF EOF
# Fill # Fill the DB up to the first eviction.
oldsize = r.dbsize oldsize = r.dbsize
id = 0 id = 0
while true while true
id += 1 id += 1
r.set(id,"foo") r.set(id,"foo")
newsize = r.dbsize newsize = r.dbsize
break if newsize == oldsize break if newsize == oldsize # A key was evicted? Stop.
oldsize = newsize oldsize = newsize
end end
inserted = r.dbsize inserted = r.dbsize
first_set_max_id = id first_set_max_id = id
puts "#{r.dbsize} keys inserted" html << "#{r.dbsize} keys inserted"
# Access keys sequentially # Access keys sequentially, so that in theory the first part will be expired
# and the latter part will not, according to perfect LRU.
puts "Access keys sequentially" STDERR.puts "Access keys sequentially"
(1..first_set_max_id).each{|id| (1..first_set_max_id).each{|id|
r.get(id) r.get(id)
# sleep 0.001 sleep 0.001
} STDERR.print(".") if (id % 150) == 0
}
# Insert more 50% keys. We expect that the new keys STDERR.puts
half = inserted/2
puts "Insert enough keys to evict half the keys we inserted" # Insert more 50% keys. We expect that the new keys will rarely be expired
add = 0 # since their last access time is recent compared to the others.
while true #
# Note that we insert the first 100 keys of the new set into DB1 instead
# of DB0, so that we can try how cross-DB eviction works.
half = inserted/2
html << "Insert enough keys to evict half the keys we inserted"
add = 0
otherdb_start_idx = id+1
otherdb_end_idx = id+100
while true
add += 1 add += 1
id += 1 id += 1
if id >= otherdb_start_idx && id <= otherdb_end_idx
r.select(1)
r.set(id,"foo")
r.select(0)
else
r.set(id,"foo") r.set(id,"foo")
end
break if r.info['evicted_keys'].to_i >= half break if r.info['evicted_keys'].to_i >= half
end end
puts "#{add} additional keys added." html << "#{add} additional keys added."
puts "#{r.dbsize} keys in DB" html << "#{r.dbsize} keys in DB"
# Check if evicted keys respect LRU # Check if evicted keys respect LRU
# We consider errors from 1 to N progressively more serious as they violate # We consider errors from 1 to N progressively more serious as they violate
# more the access pattern. # more the access pattern.
errors = 0 errors = 0
e = 1 e = 1
edecr = 1.0/(first_set_max_id/2) error_per_key = 100000.0/first_set_max_id
(1..(first_set_max_id/2)).each{|id| half_set_size = first_set_max_id/2
e -= edecr if e > 0 maxerr = 0
e = 0 if e < 0 (1..(first_set_max_id/2)).each{|id|
if r.exists(id) if id >= otherdb_start_idx && id <= otherdb_end_idx
errors += e r.select(1)
exists = r.exists(id)
r.select(0)
else
exists = r.exists(id)
end end
} if id < first_set_max_id/2
thiserr = error_per_key * ((half_set_size-id).to_f/half_set_size)
maxerr += thiserr
errors += thiserr if exists
elsif id >= first_set_max_id/2
thiserr = error_per_key * ((id-half_set_size).to_f/half_set_size)
maxerr += thiserr
errors += thiserr if !exists
end
}
errors = errors*100/maxerr
STDERR.puts "Test finished with #{errors}% error! Generating HTML on stdout."
puts "#{errors} errors!" html << "#{errors}% error!"
puts "</pre>" html << "</pre>"
$runs << errors
# Generate the graphical representation # Generate the graphical representation
(1..id).each{|id| (1..id).each{|id|
# Mark first set and added items in a different way. # Mark first set and added items in a different way.
c = "box" c = "box"
if id <= first_set_max_id if id >= otherdb_start_idx && id <= otherdb_end_idx
c << " otherdb"
elsif id <= first_set_max_id
c << " old" c << " old"
else else
c << " new" c << " new"
end end
# Add class if exists # Add class if exists
c << " ex" if r.exists(id) if id >= otherdb_start_idx && id <= otherdb_end_idx
puts "<div class=\"#{c}\"></div>" r.select(1)
} exists = r.exists(id)
r.select(0)
else
exists = r.exists(id)
end
c << " ex" if exists
html << "<div title=\"#{id}\" class=\"#{c}\"></div>"
}
# Close HTML page # Close HTML page
puts <<EOF html << <<EOF
</body> </body>
</html> </html>
EOF EOF
f = File.open(filename,"w")
f.write(html)
f.close
end
def print_avg
avg = ($runs.reduce {|a,b| a+b}) / $runs.length
puts "#{$runs.length} runs, AVG is #{avg}"
end
if ARGV.length < 1
STDERR.puts "Usage: ruby test-lru.rb <html-output-filename> [num-runs]"
exit 1
end
filename = ARGV[0]
numruns = 1
numruns = ARGV[1].to_i if ARGV.length == 2
numruns.times {
testit(filename)
print_avg if numruns != 1
}
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