Merge pull request #2273 from sul-dlss/redis_pool

Adds connection pool for redis. Increases timeout for redis.

Gemfile

@@ -3,6 +3,7 @@ source 'https://rubygems.org'
 # general Ruby/Rails gems
 gem 'aws-sdk-s3', '~> 1.17'
 gem 'committee' # Validates HTTP requests/responses per OpenAPI specification
+gem 'connection_pool' # Used for redis
 gem 'config' # Settings to manage configs on different instances
 gem 'honeybadger' # for error reporting / tracking / notifications
 gem 'jbuilder', '~> 2.5' # Build JSON APIs with ease.

Gemfile.lock

@@ -461,6 +461,7 @@ DEPENDENCIES
   capybara
   committee
   config
+  connection_pool
   debug
   dlss-capistrano
   dor-event-client (~> 1.0)

app/jobs/concerns/unique_job.rb

@@ -72,12 +72,6 @@ def lock_timeout
       3600
     end
 
-    def redis_connection
-      Redis.new(url: Settings.redis_url).tap do |conn|
-        yield conn if block_given?
-      end
-    end
-
     # @return [String] the key for locking this job/payload combination, e.g. 'lock:MySpecificJob-bt821jk7040;1'
     def queue_lock_key(*args)
       # Changes in ActiveModel object don't result in new lock (which they do when just calling to_s).
@@ -90,7 +84,7 @@ def before_enqueue_lock(*)
       now = Time.now.to_i
       new_expiry_time = now + lock_timeout + 1
 
-      redis_connection do |conn|
+      REDIS.with do |conn|
         # return true if we successfully acquired the lock
         # "Set key to hold string value if key does not exist" (otherwise no-op) -- https://redis.io/commands/setnx
         if conn.setnx(key, new_expiry_time)
@@ -123,7 +117,7 @@ def before_enqueue_lock(*)
     def clear_lock(*)
       key = queue_lock_key(*)
       Rails.logger.info("clearing lock for #{key}...")
-      redis_connection do |conn|
+      REDIS.with do |conn|
         conn.del(key).tap do |del_result|
           Rails.logger.info("...cleared lock for #{key} (del_result=#{del_result})")
         end

config/initializers/redis.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+pool_size = ENV.fetch('RAILS_MAX_THREADS', 5)
+
+REDIS = ConnectionPool.new(size: pool_size) do
+  Redis.new(url: Settings.redis_url, timeout: Settings.redis_timeout)
+end

config/initializers/sidekiq.rb

@@ -1,12 +1,15 @@
 # frozen_string_literal: true
 
+# See separate initializer for redis used by unique job.
+
+# Note the increased timeouts to try to address Redis timeouts
 Sidekiq.configure_server do |config|
-  config.redis = { url: Settings.redis_url }
+  config.redis = { url: Settings.redis_url, network_timeout: Settings.redis_timeout, pool_timeout: Settings.redis_timeout }
   # For Sidekiq Pro
   config.super_fetch!
 end
 
 Sidekiq.configure_client do |config|
-  config.redis = { url: Settings.redis_url }
+  config.redis = { url: Settings.redis_url, network_timeout: Settings.redis_timeout, pool_timeout: Settings.redis_timeout }
 end
 Sidekiq::Client.reliable_push! unless Rails.env.test?

config/settings.yml

@@ -59,6 +59,7 @@ rabbitmq:
   password: guest
 
 redis_url: redis://localhost:6379/
+redis_timeout: 5 # seconds
 
 honeybadger_checkins:
   moab_to_catalog: xyzzy
@@ -68,4 +69,5 @@ honeybadger_checkins:
 
 slow_queries:
   enable: false
-  threshold: 500
+  threshold: 500
+