From 32a549432b119d827693d547def557931bad352a Mon Sep 17 00:00:00 2001 From: antirez Date: Mon, 11 Jul 2016 16:22:09 +0200 Subject: [PATCH] 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. --- utils/lru/README | 10 +- utils/lru/test-lru.rb | 272 +++++++++++++++++++++++++++--------------- 2 files changed, 182 insertions(+), 100 deletions(-) diff --git a/utils/lru/README b/utils/lru/README index 288189e3..f043b297 100644 --- a/utils/lru/README +++ b/utils/lru/README @@ -3,11 +3,17 @@ 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. +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 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 + 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 diff --git a/utils/lru/test-lru.rb b/utils/lru/test-lru.rb index ee0527ef..dadc6d50 100644 --- a/utils/lru/test-lru.rb +++ b/utils/lru/test-lru.rb @@ -1,112 +1,188 @@ 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 +$runs = []; # Remember the error rate of each run for average purposes. -puts < - - -
+    .new {
+        border: 1px green solid;
+    }
+
+    .otherdb {
+        border: 1px red solid;
+    }
+
+    .ex {
+        background-color: #666;
+    }
+    
+    
 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 sequentially
-
-puts "Access keys sequentially"
-(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 "
"
-
-# 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"
+    # Fill the DB up to the first eviction.
+    oldsize = r.dbsize
+    id = 0
+    while true
+        id += 1
+        r.set(id,"foo")
+        newsize = r.dbsize
+        break if newsize == oldsize # A key was evicted? Stop.
+        oldsize = newsize
     end
 
-    # Add class if exists
-    c << " ex" if r.exists(id)
-    puts "
"
-}
+    inserted = r.dbsize
+    first_set_max_id = id
+    html << "#{r.dbsize} keys inserted"
 
-# Close HTML page
+    # Access keys sequentially, so that in theory the first part will be expired
+    # and the latter part will not, according to perfect LRU.
 
-puts <
-
+    STDERR.puts "Access keys sequentially"
+    (1..first_set_max_id).each{|id|
+        r.get(id)
+        sleep 0.001
+        STDERR.print(".") if (id % 150) == 0
+    }
+    STDERR.puts
+
+    # Insert more 50% keys. We expect that the new keys will rarely be expired
+    # since their last access time is recent compared to the others.
+    #
+    # 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
+        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")
+        end
+        break if r.info['evicted_keys'].to_i >= half
+    end
+
+    html << "#{add} additional keys added."
+    html << "#{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
+    error_per_key = 100000.0/first_set_max_id
+    half_set_size = first_set_max_id/2
+    maxerr = 0
+    (1..(first_set_max_id/2)).each{|id|
+        if id >= otherdb_start_idx && id <= otherdb_end_idx
+            r.select(1)
+            exists = r.exists(id)
+            r.select(0)
+        else
+            exists = r.exists(id)
+        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."
+
+    html << "#{errors}% error!"
+    html << "
" + $runs << errors + + # Generate the graphical representation + (1..id).each{|id| + # Mark first set and added items in a different way. + c = "box" + if id >= otherdb_start_idx && id <= otherdb_end_idx + c << " otherdb" + elsif id <= first_set_max_id + c << " old" + else + c << " new" + end + + # Add class if exists + if id >= otherdb_start_idx && id <= otherdb_end_idx + r.select(1) + exists = r.exists(id) + r.select(0) + else + exists = r.exists(id) + end + + c << " ex" if exists + html << "
" + } + + # Close HTML page + + html << < + EOF + + f = File.open(filename,"w") + f.write(html) + f.close +end + +def print_avg + avg = ($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 [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 +}