Handle infinite request retry on connection error

lib/clickhouse/cluster.rb

@@ -32,12 +32,15 @@ def initialize(config)
   private
 
     def method_missing(*args, &block)
-      pond.checkout do |connection|
-        connection.send(*args, &block)
+      trys_left = pond.available.count
+      begin
+        pond.checkout do |connection|
+          trys_left -= 1
+          connection.send(*args, &block)
+        end
+      rescue ::Clickhouse::ConnectionError
+        retry if pond.available.any? && trys_left.positive?
       end
-    rescue ::Clickhouse::ConnectionError
-      retry if pond.available.any?
     end
-
   end
 end

test/unit/connection/test_cluster.rb

@@ -74,6 +74,16 @@ class TestCluser < MiniTest::Test
             ), cluster.pond.available.collect(&:url)
           end
         end
+
+        describe "when timeout error gets raised while running the query" do
+          it "does not repeat request more then cluster's size times" do
+            Clickhouse::Connection.any_instance.expects(:ping!).at_least_once
+            Clickhouse::Connection.any_instance.stubs(:get).at_most(3).raises(Clickhouse::RequestTimedOut)
+
+            cluster = Clickhouse::Cluster.new :urls => %w(http://localhost:1234 http://localhost:1235 http://localhost:1236)
+            cluster.get "SELECT 1"
+          end
+        end
       end
 
     end