From 7e68118d91f6c4c25e1af810879da3d39321f726 Mon Sep 17 00:00:00 2001
From: Dzmitry Nikitsin <dzmitry.nikitsin@gmail.com>
Date: Mon, 3 Aug 2015 15:27:08 -0400
Subject: [PATCH 1/9] introduced default shards

---
 lib/octopus/proxy.rb | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/lib/octopus/proxy.rb b/lib/octopus/proxy.rb
index f5cf4934..cf2efad2 100644
--- a/lib/octopus/proxy.rb
+++ b/lib/octopus/proxy.rb
@@ -19,6 +19,9 @@ def initialize_shards(config)
       @adapters = Set.new
       @config = ActiveRecord::Base.connection_pool_without_octopus.spec.config
 
+      @default_shard = config['defaults'].try(:[], 'shard') || :master
+      @default_slave_group = config['defaults'].try(:[], 'slave_group')
+
       unless config.nil?
         @entire_sharded = config['entire_sharded']
         @shards_config = config[Octopus.rails_env]
@@ -73,6 +76,10 @@ def initialize_shards(config)
         end
       end
 
+      if (@default_shard != :master) && @shards_slave_groups.present? && !@shards_slave_groups[@default_shard].try(:has_key?, @default_slave_group)
+        fail 'default slave group should be included in default shard'
+      end
+
       @shards[:master] ||= ActiveRecord::Base.connection_pool_without_octopus
     end
 
@@ -98,7 +105,7 @@ def current_model=(model)
     end
 
     def current_shard
-      Thread.current['octopus.current_shard'] ||= :master
+      Thread.current['octopus.current_shard'] ||= @default_shard
     end
 
     def current_shard=(shard_symbol)
@@ -146,7 +153,7 @@ def current_group=(group_symbol)
     end
 
     def current_slave_group
-      Thread.current['octopus.current_slave_group']
+      Thread.current['octopus.current_slave_group'] ||= @default_slave_group
     end
 
     def current_slave_group=(slave_group_symbol)

From 43bcb9536fc4a30d0d348a8b830460614b5a1463 Mon Sep 17 00:00:00 2001
From: Dzmitry Nikitsin <dzmitry.nikitsin@gmail.com>
Date: Tue, 4 Aug 2015 21:58:57 -0400
Subject: [PATCH 2/9] make work with shard + slave groups & default value for
 slave group

---
 lib/octopus/proxy.rb | 30 +++++++++++++++---------------
 threads              |  0
 2 files changed, 15 insertions(+), 15 deletions(-)
 create mode 100644 threads

diff --git a/lib/octopus/proxy.rb b/lib/octopus/proxy.rb
index cf2efad2..1b0e56fb 100644
--- a/lib/octopus/proxy.rb
+++ b/lib/octopus/proxy.rb
@@ -19,8 +19,11 @@ def initialize_shards(config)
       @adapters = Set.new
       @config = ActiveRecord::Base.connection_pool_without_octopus.spec.config
 
-      @default_shard = config['defaults'].try(:[], 'shard') || :master
-      @default_slave_group = config['defaults'].try(:[], 'slave_group')
+      @default_shard = config['defaults'].try(:[], 'shard')
+      fail 'default shard shoule be set' if @default_shard.blank?
+
+      default_slave_group_name = config['defaults'].try(:[], 'slave_group')
+      @default_slave_groups = @shards_config.keys.inject(HashWithIndifferentAccess.new) { |h, k| h[k] = default_slave_group_name; h }
 
       unless config.nil?
         @entire_sharded = config['entire_sharded']
@@ -76,11 +79,7 @@ def initialize_shards(config)
         end
       end
 
-      if (@default_shard != :master) && @shards_slave_groups.present? && !@shards_slave_groups[@default_shard].try(:has_key?, @default_slave_group)
-        fail 'default slave group should be included in default shard'
-      end
-
-      @shards[:master] ||= ActiveRecord::Base.connection_pool_without_octopus
+      #@shards[:master] ||= ActiveRecord::Base.connection_pool_without_octopus
     end
 
     def initialize_replication(config)
@@ -109,7 +108,6 @@ def current_shard
     end
 
     def current_shard=(shard_symbol)
-      self.current_slave_group = nil
       if shard_symbol.is_a?(Array)
         shard_symbol.each { |symbol| fail "Nonexistent Shard Name: #{symbol}" if @shards[symbol].nil? }
       elsif shard_symbol.is_a?(Hash)
@@ -136,6 +134,7 @@ def current_shard=(shard_symbol)
         fail "Nonexistent Shard Name: #{shard_symbol}" if @shards[shard_symbol].nil?
       end
 
+      self.current_slave_group ||= @default_slave_groups[shard_symbol]
       Thread.current['octopus.current_shard'] = shard_symbol
     end
 
@@ -153,7 +152,7 @@ def current_group=(group_symbol)
     end
 
     def current_slave_group
-      Thread.current['octopus.current_slave_group'] ||= @default_slave_group
+      Thread.current['octopus.current_slave_group'] || @default_slave_groups[current_shard]
     end
 
     def current_slave_group=(slave_group_symbol)
@@ -209,7 +208,7 @@ def shards_for_group(group)
     # reconnect, but in Rails 3.1 the flag prevents this.
     def safe_connection(connection_pool)
       connection_pool.automatic_reconnect ||= true
-      if !connection_pool.connected? && @shards[:master].connection.query_cache_enabled
+      if !connection_pool.connected? && @shards[@default_shard].connection.query_cache_enabled
         connection_pool.connection.enable_query_cache!
       end
       connection_pool.connection
@@ -242,7 +241,7 @@ def send_queries_to_multiple_shards(shards, &block)
     end
 
     def clean_connection_proxy
-      self.current_shard = :master
+      self.current_shard = @default_shard
       self.current_model = nil
       self.current_group = nil
       self.block = nil
@@ -250,13 +249,13 @@ def clean_connection_proxy
 
     def check_schema_migrations(shard)
       OctopusModel.using(shard).connection.table_exists?(
-        ActiveRecord::Migrator.schema_migrations_table_name,
+          ActiveRecord::Migrator.schema_migrations_table_name,
       ) || OctopusModel.using(shard).connection.initialize_schema_migrations_table
     end
 
     def transaction(options = {}, &block)
       if !sharded && current_model_replicated?
-        run_queries_on_shard(:master) do
+        run_queries_on_shard(@default_shard) do
           select_connection.transaction(options, &block)
         end
       else
@@ -356,7 +355,7 @@ def with_each_healthy_shard
       end
 
       ar_pools.each do |pool|
-        next if pool == @shards[:master] # Already handled this
+        next if pool == @shards[@default_shard] # Already handled this
 
         begin
           yield(pool)
@@ -420,7 +419,7 @@ def send_queries_to_selected_slave(method, *args, &block)
       if current_model.replicated || fully_replicated?
         selected_slave = @slaves_load_balancer.next
       else
-        selected_slave = :master
+        selected_slave = @default_shard
       end
 
       send_queries_to_slave(selected_slave, method, *args, &block)
@@ -495,3 +494,4 @@ def structurally_slave_group?(config)
     end
   end
 end
+
diff --git a/threads b/threads
new file mode 100644
index 00000000..e69de29b

From 99ace335f51d9b227b18285974ea418d05642630 Mon Sep 17 00:00:00 2001
From: Dzmitry Nikitsin <dzmitry.nikitsin@gmail.com>
Date: Tue, 4 Aug 2015 22:24:12 -0400
Subject: [PATCH 3/9] fixed octopus

---
 lib/octopus/proxy.rb | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/lib/octopus/proxy.rb b/lib/octopus/proxy.rb
index 1b0e56fb..bf04bac8 100644
--- a/lib/octopus/proxy.rb
+++ b/lib/octopus/proxy.rb
@@ -22,15 +22,14 @@ def initialize_shards(config)
       @default_shard = config['defaults'].try(:[], 'shard')
       fail 'default shard shoule be set' if @default_shard.blank?
 
-      default_slave_group_name = config['defaults'].try(:[], 'slave_group')
-      @default_slave_groups = @shards_config.keys.inject(HashWithIndifferentAccess.new) { |h, k| h[k] = default_slave_group_name; h }
-
       unless config.nil?
         @entire_sharded = config['entire_sharded']
         @shards_config = config[Octopus.rails_env]
       end
 
       @shards_config ||= []
+      default_slave_group_name = config['defaults'].try(:[], 'slave_group')
+      @default_slave_groups = @shards_config.keys.inject(HashWithIndifferentAccess.new) { |h, k| h[k] = default_slave_group_name; h }
 
       @shards_config.each do |key, value|
         if value.is_a?(String)

From 633adf941b546c23c46d9f5719e47310db57ba83 Mon Sep 17 00:00:00 2001
From: Dzmitry Nikitsin <dzmitry.nikitsin@gmail.com>
Date: Tue, 4 Aug 2015 23:02:18 -0400
Subject: [PATCH 4/9] fixed issue with deploy

---
 lib/octopus/proxy.rb | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/octopus/proxy.rb b/lib/octopus/proxy.rb
index bf04bac8..57923535 100644
--- a/lib/octopus/proxy.rb
+++ b/lib/octopus/proxy.rb
@@ -29,7 +29,11 @@ def initialize_shards(config)
 
       @shards_config ||= []
       default_slave_group_name = config['defaults'].try(:[], 'slave_group')
-      @default_slave_groups = @shards_config.keys.inject(HashWithIndifferentAccess.new) { |h, k| h[k] = default_slave_group_name; h }
+      if @shards_config.is_a?(Hash)
+        @default_slave_groups = @shards_config.keys.inject(HashWithIndifferentAccess.new) { |h, k| h[k] = default_slave_group_name; h }
+      else
+        @default_slave_groups = {}
+      end
 
       @shards_config.each do |key, value|
         if value.is_a?(String)

From 906ae0c5179012607467c0cde4510d8f15e40651 Mon Sep 17 00:00:00 2001
From: Dzmitry Nikitsin <dzmitry.nikitsin@gmail.com>
Date: Fri, 21 Aug 2015 14:17:12 -0400
Subject: [PATCH 5/9] fixed shard with slaves

---
 lib/octopus/proxy.rb       | 32 +++++++++++++++++---------------
 lib/octopus/slave_group.rb |  1 -
 threads                    |  0
 3 files changed, 17 insertions(+), 16 deletions(-)
 delete mode 100644 threads

diff --git a/lib/octopus/proxy.rb b/lib/octopus/proxy.rb
index 57923535..93285d71 100644
--- a/lib/octopus/proxy.rb
+++ b/lib/octopus/proxy.rb
@@ -54,8 +54,7 @@ def initialize_shards(config)
             slave_group_configs.each do |slave_group_name, slave_configs|
               slaves = HashWithIndifferentAccess.new
               slave_configs.each do |slave_name, slave_config|
-                @shards[slave_name.to_sym] = connection_pool_for(slave_config, "#{value['adapter']}_connection")
-                slaves[slave_name.to_sym] = slave_name.to_sym
+                slaves[slave_name.to_sym] = connection_pool_for(slave_config, "#{value['adapter']}_connection")
               end
               slave_groups[slave_group_name.to_sym] = Octopus::SlaveGroup.new(slaves)
             end
@@ -81,8 +80,6 @@ def initialize_shards(config)
           end
         end
       end
-
-      #@shards[:master] ||= ActiveRecord::Base.connection_pool_without_octopus
     end
 
     def initialize_replication(config)
@@ -111,11 +108,13 @@ def current_shard
     end
 
     def current_shard=(shard_symbol)
+      self.current_slave_group = nil
+
       if shard_symbol.is_a?(Array)
         shard_symbol.each { |symbol| fail "Nonexistent Shard Name: #{symbol}" if @shards[symbol].nil? }
       elsif shard_symbol.is_a?(Hash)
         hash = shard_symbol
-        shard_symbol = hash[:shard]
+        shard_symbol =       hash[:shard]
         slave_group_symbol = hash[:slave_group]
 
         if shard_symbol.nil? && slave_group_symbol.nil?
@@ -127,8 +126,8 @@ def current_shard=(shard_symbol)
         end
 
         if slave_group_symbol.present?
-          if (@shards_slave_groups.try(:[], shard_symbol).present? && @shards_slave_groups[shard_symbol][slave_group_symbol].nil?) ||
-              (@shards_slave_groups.try(:[], shard_symbol).nil? && @slave_groups[slave_group_symbol].nil?)
+          if (slave_group_symbol != :master) && ((@shards_slave_groups.try(:[], shard_symbol).present? && @shards_slave_groups[shard_symbol][slave_group_symbol].nil?) ||
+              (@shards_slave_groups.try(:[], shard_symbol).nil? && @slave_groups[slave_group_symbol].nil?))
             fail "Nonexistent Slave Group Name: #{slave_group_symbol} in shards config: #{@shards_config.inspect}"
           end
           self.current_slave_group = slave_group_symbol
@@ -137,7 +136,7 @@ def current_shard=(shard_symbol)
         fail "Nonexistent Shard Name: #{shard_symbol}" if @shards[shard_symbol].nil?
       end
 
-      self.current_slave_group ||= @default_slave_groups[shard_symbol]
+      #self.current_slave_group ||= @default_slave_groups[shard_symbol]
       Thread.current['octopus.current_shard'] = shard_symbol
     end
 
@@ -217,8 +216,8 @@ def safe_connection(connection_pool)
       connection_pool.connection
     end
 
-    def select_connection
-      safe_connection(@shards[shard_name])
+    def select_connection(connection = nil)
+      safe_connection(connection || @shards[shard_name])
     end
 
     def shard_name
@@ -275,8 +274,10 @@ def method_missing(method, *args, &block)
       elsif should_send_queries_to_shard_slave_group?(method)
         send_queries_to_shard_slave_group(method, *args, &block)
       elsif should_send_queries_to_slave_group?(method)
+        raise NotImplementedError.new
         send_queries_to_slave_group(method, *args, &block)
       elsif should_send_queries_to_replicated_databases?(method)
+        raise NotImplementedError.new
         send_queries_to_selected_slave(method, *args, &block)
       else
         select_connection.send(method, *args, &block)
@@ -321,7 +322,11 @@ def should_send_queries_to_shard_slave_group?(method)
     end
 
     def send_queries_to_shard_slave_group(method, *args, &block)
-      send_queries_to_balancer(@shards_slave_groups[current_shard][current_slave_group], method, *args, &block)
+      if current_slave_group == :master
+        send_queries_to_slave(@shards[current_shard], method, *args, &block)
+      else
+        send_queries_to_balancer(@shards_slave_groups[current_shard][current_slave_group], method, *args, &block)
+      end
     end
 
     def should_send_queries_to_slave_group?(method)
@@ -454,9 +459,7 @@ def send_queries_to_balancer(balancer, method, *args, &block)
     # Temporarily switch `current_shard` to the specified slave and send queries to it
     # while preserving `current_shard`
     def send_queries_to_slave(slave, method, *args, &block)
-      using_shard(slave) do
-        select_connection.send(method, *args, &block)
-      end
+      select_connection(slave).send(method, *args, &block)
     end
 
     # Temporarily block cleaning connection proxy and run the block
@@ -497,4 +500,3 @@ def structurally_slave_group?(config)
     end
   end
 end
-
diff --git a/lib/octopus/slave_group.rb b/lib/octopus/slave_group.rb
index e36611e9..944e75f1 100644
--- a/lib/octopus/slave_group.rb
+++ b/lib/octopus/slave_group.rb
@@ -1,7 +1,6 @@
 module Octopus
   class SlaveGroup
     def initialize(slaves)
-      slaves = HashWithIndifferentAccess.new(slaves)
       slaves_list = slaves.values
       @load_balancer = Octopus::LoadBalancing::RoundRobin.new(slaves_list)
     end
diff --git a/threads b/threads
deleted file mode 100644
index e69de29b..00000000

From 6f91058f33de314e28c6b5b372d3dd16e343c1cc Mon Sep 17 00:00:00 2001
From: Dzmitry Nikitsin <dzmitry.nikitsin@gmail.com>
Date: Sat, 22 Aug 2015 15:56:22 -0400
Subject: [PATCH 6/9] implemented run on slave in slave groups

---
 lib/octopus/load_balancing/round_robin.rb |  8 ++++++--
 lib/octopus/proxy.rb                      | 21 +++++++++++++++++++--
 lib/octopus/slave_group.rb                | 18 +++++++++++++++---
 3 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/lib/octopus/load_balancing/round_robin.rb b/lib/octopus/load_balancing/round_robin.rb
index 7c98d993..195aa36a 100644
--- a/lib/octopus/load_balancing/round_robin.rb
+++ b/lib/octopus/load_balancing/round_robin.rb
@@ -11,8 +11,12 @@ def initialize(slaves_list)
       end
 
       # Returns the next available slave in the pool
-      def next
-        @slaves_list[@slave_index = (@slave_index + 1) % @slaves_list.length]
+      def next(index = nil)
+        if index
+          @slaves_list[index]
+        else
+          @slaves_list[@slave_index = (@slave_index + 1) % @slaves_list.length]
+        end
       end
     end
   end
diff --git a/lib/octopus/proxy.rb b/lib/octopus/proxy.rb
index 93285d71..314d58b3 100644
--- a/lib/octopus/proxy.rb
+++ b/lib/octopus/proxy.rb
@@ -109,6 +109,7 @@ def current_shard
 
     def current_shard=(shard_symbol)
       self.current_slave_group = nil
+      self.current_slave = nil
 
       if shard_symbol.is_a?(Array)
         shard_symbol.each { |symbol| fail "Nonexistent Shard Name: #{symbol}" if @shards[symbol].nil? }
@@ -116,6 +117,7 @@ def current_shard=(shard_symbol)
         hash = shard_symbol
         shard_symbol =       hash[:shard]
         slave_group_symbol = hash[:slave_group]
+        slave_symbol = hash[:slave]
 
         if shard_symbol.nil? && slave_group_symbol.nil?
           fail 'Neither shard or slave group must be specified'
@@ -132,11 +134,18 @@ def current_shard=(shard_symbol)
           end
           self.current_slave_group = slave_group_symbol
         end
+
+        if slave_symbol.present?
+          unless @shards_slave_groups[shard_symbol].try(:[], slave_group_symbol).try(:has_slave?, slave_symbol)
+            fail "Nonexistent Slave Name: #{slave_symbol} in slave group: #{slave_group_symbol}"
+          end
+
+          self.current_slave = slave_symbol
+        end
       else
         fail "Nonexistent Shard Name: #{shard_symbol}" if @shards[shard_symbol].nil?
       end
 
-      #self.current_slave_group ||= @default_slave_groups[shard_symbol]
       Thread.current['octopus.current_shard'] = shard_symbol
     end
 
@@ -161,6 +170,14 @@ def current_slave_group=(slave_group_symbol)
       Thread.current['octopus.current_slave_group'] = slave_group_symbol
     end
 
+    def current_slave
+      Thread.current['octopus.current_slave']
+    end
+
+    def current_slave=(slave_symbol)
+      Thread.current['octopus.current_slave'] = slave_symbol
+    end
+
     def block
       Thread.current['octopus.block']
     end
@@ -453,7 +470,7 @@ def slaves_grouped?
     # Temporarily switch `current_shard` to the next slave in a slave group and send queries to it
     # while preserving `current_shard`
     def send_queries_to_balancer(balancer, method, *args, &block)
-      send_queries_to_slave(balancer.next, method, *args, &block)
+      send_queries_to_slave(balancer.next(current_slave), method, *args, &block)
     end
 
     # Temporarily switch `current_shard` to the specified slave and send queries to it
diff --git a/lib/octopus/slave_group.rb b/lib/octopus/slave_group.rb
index 944e75f1..20111e09 100644
--- a/lib/octopus/slave_group.rb
+++ b/lib/octopus/slave_group.rb
@@ -1,12 +1,24 @@
 module Octopus
   class SlaveGroup
     def initialize(slaves)
-      slaves_list = slaves.values
+      @name_index_map = HashWithIndifferentAccess.new
+      slaves_list, index = [], 0
+
+      slaves.each do |name, db_connection_pool|
+        slaves_list << db_connection_pool
+        @name_index_map[name] = index
+        index += 1
+      end
+
       @load_balancer = Octopus::LoadBalancing::RoundRobin.new(slaves_list)
     end
 
-    def next
-      @load_balancer.next
+    def has_slave?(slave_name)
+      @name_index_map.has_key?(slave_name)
+    end
+
+    def next(slave_name = nil)
+      @load_balancer.next(@name_index_map[slave_name])
     end
   end
 end

From 76f4f5a4f698be5339d8edb996da8d62306de279 Mon Sep 17 00:00:00 2001
From: Dzmitry Nikitsin <dzmitry.nikitsin@gmail.com>
Date: Mon, 24 Aug 2015 19:16:55 -0400
Subject: [PATCH 7/9] fixed issue, when cache was not reset for slaves

---
 lib/octopus/proxy.rb       |  9 ++++++++-
 lib/octopus/slave_group.rb | 12 ++++++++----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/lib/octopus/proxy.rb b/lib/octopus/proxy.rb
index 314d58b3..66269305 100644
--- a/lib/octopus/proxy.rb
+++ b/lib/octopus/proxy.rb
@@ -15,6 +15,7 @@ def initialize_shards(config)
       @shards = HashWithIndifferentAccess.new
       @shards_slave_groups = HashWithIndifferentAccess.new
       @slave_groups = HashWithIndifferentAccess.new
+      @shard_servers = HashWithIndifferentAccess.new
       @groups = {}
       @adapters = Set.new
       @config = ActiveRecord::Base.connection_pool_without_octopus.spec.config
@@ -44,6 +45,7 @@ def initialize_shards(config)
           value.merge!(:octopus_shard => key)
           initialize_adapter(value['adapter'])
           @shards[key.to_sym] = connection_pool_for(value, "#{value['adapter']}_connection")
+          @shard_servers[key.to_sym] = [@shards[key.to_sym]]
 
           slave_group_configs = value.select do |_k, v|
             structurally_slave_group? v
@@ -55,6 +57,7 @@ def initialize_shards(config)
               slaves = HashWithIndifferentAccess.new
               slave_configs.each do |slave_name, slave_config|
                 slaves[slave_name.to_sym] = connection_pool_for(slave_config, "#{value['adapter']}_connection")
+                @shard_servers[key.to_sym] << slaves[slave_name.to_sym]
               end
               slave_groups[slave_group_name.to_sym] = Octopus::SlaveGroup.new(slaves)
             end
@@ -356,9 +359,13 @@ def send_queries_to_slave_group(method, *args, &block)
 
     protected
 
+    def shard_servers
+      @shard_servers[current_shard]
+    end
+
     # Ensure that a single failing slave doesn't take down the entire application
     def with_each_healthy_shard
-      @shards.each do |shard_name, v|
+      shard_servers.each do |shard_name, v|
         begin
           yield(v)
         rescue => e
diff --git a/lib/octopus/slave_group.rb b/lib/octopus/slave_group.rb
index 20111e09..16a507fc 100644
--- a/lib/octopus/slave_group.rb
+++ b/lib/octopus/slave_group.rb
@@ -2,23 +2,27 @@ module Octopus
   class SlaveGroup
     def initialize(slaves)
       @name_index_map = HashWithIndifferentAccess.new
-      slaves_list, index = [], 0
+      @slaves_list, index = [], 0
 
       slaves.each do |name, db_connection_pool|
-        slaves_list << db_connection_pool
+        @slaves_list << db_connection_pool
         @name_index_map[name] = index
         index += 1
       end
 
-      @load_balancer = Octopus::LoadBalancing::RoundRobin.new(slaves_list)
+      @load_balancer = Octopus::LoadBalancing::RoundRobin.new(@slaves_list)
     end
 
     def has_slave?(slave_name)
       @name_index_map.has_key?(slave_name)
     end
 
+    def slaves
+      @slaves_list
+    end
+
     def next(slave_name = nil)
       @load_balancer.next(@name_index_map[slave_name])
     end
   end
-end
+end
\ No newline at end of file

From 1f551534c23627c283c7237026c15c62b8d9ecee Mon Sep 17 00:00:00 2001
From: Dzmitry Nikitsin <dzmitry.nikitsin@gmail.com>
Date: Mon, 24 Aug 2015 19:21:19 -0400
Subject: [PATCH 8/9] fixed typo

---
 lib/octopus/proxy.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/octopus/proxy.rb b/lib/octopus/proxy.rb
index 66269305..fa0b04e3 100644
--- a/lib/octopus/proxy.rb
+++ b/lib/octopus/proxy.rb
@@ -365,12 +365,12 @@ def shard_servers
 
     # Ensure that a single failing slave doesn't take down the entire application
     def with_each_healthy_shard
-      shard_servers.each do |shard_name, v|
+      shard_servers.each do |v|
         begin
           yield(v)
         rescue => e
           if Octopus.robust_environment?
-            Octopus.logger.error "Error on shard #{shard_name}: #{e.message}"
+            Octopus.logger.error "Error on shard #{v.spec.config['host']}, database #{v.spec.config['database']}: #{e.message}"
           else
             raise
           end

From c4e35941a2beef6bb6df14fbc6a466515e446de4 Mon Sep 17 00:00:00 2001
From: Yegor Zdanovich <yegor.zdanovich@gmail.com>
Date: Thu, 31 Mar 2016 11:31:39 +0300
Subject: [PATCH 9/9] fix stack level to deep accoring
 https://github.com/thiagopradi/octopus/commit/b1e70ac184d2a0898529bf2a1cd7d69870bb00ab

---
 lib/octopus/association_shard_tracking.rb       | 4 ++--
 spec/octopus/association_shard_tracking_spec.rb | 6 ++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/octopus/association_shard_tracking.rb b/lib/octopus/association_shard_tracking.rb
index 692b5d0f..87a6656f 100644
--- a/lib/octopus/association_shard_tracking.rb
+++ b/lib/octopus/association_shard_tracking.rb
@@ -26,8 +26,8 @@ module QueryOnCurrentShard
 
       METHODS.each do |m|
         define_method m.to_sym do |*args, &block|
-          if self.respond_to?(:proxy_association) && proxy_association
-            proxy_association.owner.run_on_shard { super(*args, &block) }
+          if defined?(@association) && @association
+            @association.owner.run_on_shard { super(*args, &block) }
           else
             super(*args, &block)
           end
diff --git a/spec/octopus/association_shard_tracking_spec.rb b/spec/octopus/association_shard_tracking_spec.rb
index e0206343..a61d69e8 100644
--- a/spec/octopus/association_shard_tracking_spec.rb
+++ b/spec/octopus/association_shard_tracking_spec.rb
@@ -630,6 +630,12 @@
         expect(@brazil_client.comments.count).to eq(2)
       end
 
+      it 'group + count' do
+        expect(@brazil_client.comments.group(:id).count.length).to eq(1)
+        _cmt = @brazil_client.comments.create(:name => 'Builded Comment')
+        expect(@brazil_client.comments.group(:id).count.length).to eq(2)
+      end
+
       it 'size' do
         expect(@brazil_client.comments.size).to eq(1)
         _cmt = @brazil_client.comments.create(:name => 'Builded Comment')