alekseyl

EXPLAIN ANALYZE SELECT * FROM words WHERE word LIKE 'o%' ORDER BY word USING < LIMIT 10;
                                                                  QUERY PLAN                                                                  
----------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=20178.09..20178.12 rows=10 width=440) (actual time=45.203..45.215 rows=10 loops=1)
   ->  Sort  (cost=20178.09..20199.27 rows=8471 width=440) (actual time=45.202..45.203 rows=10 loops=1)
         Sort Key: word
         Sort Method: top-N heapsort  Memory: 29kB
         ->  Bitmap Heap Scan on words  (cost=218.41..19995.04 rows=8471 width=440) (actual time=4.769..26.591 rows=11599 loops=1)
               Filter: ((word)::text ~~ 'o%'::text)
               Heap Blocks: exact=1192

alekseyl

EXPLAIN ANALYZE SELECT * FROM words WHERE word LIKE 'o%' ORDER BY word USING ~<~ LIMIT 10;
                                                               QUERY PLAN                                                               
----------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=0.42..36.23 rows=10 width=440) (actual time=0.135..0.189 rows=10 loops=1)
   ->  Index Scan using index_words_word on words  (cost=0.42..30333.13 rows=8471 width=440) (actual time=0.133..0.185 rows=10 loops=1)
         Index Cond: (((word)::text ~>=~ 'o'::text) AND ((word)::text ~<~ 'p'::text))
         Filter: ((word)::text ~~ 'o%'::text)
 Planning time: 0.299 ms
 Execution time: 0.216 ms

alekseyl

env['rack.session'] = ActionDispatch::Cookies::EncryptedCookieJar.new(cookies)[:_application_session]
current_user = Warden::SessionSerializer.new(env).fetch(:user)

alekseyl

+----------------+-----------------+-----------------+-----------------+--------------+
| Array size     | order by random | random() < 0.xx | generate_series | M partials   |
| 10             | 0.25ms / 1.35   | 0.23ms / 1.2    | 0.12ms / 0.64   | 0.19ms / 1.0 |
| 100            | 0.58ms / 2.85   | 0.41ms / 2.04   | 0.14ms / 0.69   | 0.2ms / 1.0  |
| 1000           | 3.88ms / 7.3    | 2.49ms / 4.7    | 0.47ms / 0.88   | 0.53ms / 1.0 |
| 10000          | 45.59ms / 15.57 | 29.09ms / 9.94  | 2.87ms / 0.98   | 2.93ms / 1.0 |
+----------------+-----------------+-----------------+-----------------+--------------+

alekseyl

+----------------+-----------------+-----------------+-----------------+---------------+---------------+-----------------+----------------+----------------+
| N/cards/M      | order by random | random() < 0.xx | generate_series | M partials    | ruby way      | Unfold          | ORM random(rw) | ORM random(mp) |
| 10 / 10 / 5    | 0.32ms / 4.27   | 0.26ms / 3.55   | 0.25ms / 3.44   | 0.31ms / 4.13 | 0.28ms / 3.82 | 0.07ms / 1.0    | 0.17ms / 2.3   | 0.19ms / 2.55  |
| 100 / 10 / 5   | 0.66ms / 9.69   | 0.47ms / 6.9    | 0.26ms / 3.85   | 0.29ms / 4.22 | 0.31ms / 4.59 | 0.07ms / 1.0    | 0.2ms / 3.01   | 0.19ms / 2.74  |
| 1000 / 10 / 5  | 4.39ms / 10.09  | 2.98ms / 6.86   | 0.51ms / 1.16   | 0.57ms / 1.32 | 0.66ms / 1.51 | 2.89ms / 6.63   | 0.55ms / 1.26  | 0.44ms / 1.0   |
| 10000 / 10 / 5 | 43.06ms / 22.11 | 26.48ms / 13.6  | 1.79ms / 0.92   | 2.17ms / 1.11 | 3.18ms / 1.63 | 22.89ms / 11.75 | 3.01ms / 1.55  | 1.95ms / 1.0   |
+----------------+-----------------+-----------------+-----------------+----------

alekseyl

proxy_cache_pass /path/to/cache levels= keys_zone=rails_cache:10m max_size=10g use_temp_path=off inactive=120m;
  
  location / {
    try_files $uri @rails;
  }
  
  location @rails {
    # lets skip authorized user.
    proxy_no_cache $cookie_remember_user_token;
    proxy_cache_bypass $cookie_remember_user_token;

alekseyl

#  def to_base62
#    Base62.encode(to_s)
#  end

2.4.1 :001 > redis = Redis.new
 => #<Redis client v4.0.1 for redis://127.0.0.1:6379/0> 
2.4.1 :002 > redis.flushdb
2.4.1 :003 > redis.info(:memory)['used_memory_human']
 => "670.55K" 
2.4.1 :004 > redis.pipelined { 100000.times{|i| redis.incr( "user:#{i}" ) }; }; :done

alekseyl

def redis_memory_test
    results = {}
    
    redis = Redis.new
    redis.flushdb
    results[:clear] = redis.info(:memory)['used_memory'].to_i
    
    (2..128).each do |i|
      redis.pipelined do
        10000.times { redis.incr( SecureRandom.urlsafe_base64( i  ) ) }

alekseyl

module RSmazCompressor
  def self.compress(value); RSmaz.compress(value) end
  def self.decompress(value); RSmaz.decompress(value) end
end

module ZLibJSONCompressor
  def self.compress(value); Zlib.deflate(value.to_json) end
  def self.decompress(value); JSON.load( Zlib.inflate( value ) )end
end

alekseyl

Redis.include( MeRedis )
# zip key crumbs user, card, card_preview, zips integer crumbs to base62, 
# for keys starting with card_preview prefix compress values with Zlib 
# for keys starting with user or card compress values with ActiveRecordJSONCompressor
Redis.configure( 
  hash_max_ziplist_entries: 256,
  zip_crumbs: %i[user card card_preview], # -> { user: :u, card: :c, card_preview: :c0 }
  integers_to_base62: true,
  compress_namespaces: {
      :card_preview => MeRedis::ZipValues::ZlibCompressor,