diff --git a/test/plugin_helper/test_retry_state.rb b/test/plugin_helper/test_retry_state.rb
index a6cd7300dc..824151c3a8 100644
--- a/test/plugin_helper/test_retry_state.rb
+++ b/test/plugin_helper/test_retry_state.rb
@@ -18,6 +18,21 @@ class Dummy < Fluent::Plugin::TestBase
     helpers :retry_state
   end
 
+  class RetryRecord
+    attr_reader :retry_count, :elapsed_sec, :is_secondary
+    def initialize(retry_count, elapsed_sec, is_secondary)
+      @retry_count = retry_count # This is Nth retryment
+      @elapsed_sec = elapsed_sec
+      @is_secondary = is_secondary
+    end
+
+    def ==(obj)
+      @retry_count == obj.retry_count &&
+      @elapsed_sec == obj.elapsed_sec &&
+      @is_secondary == obj.is_secondary
+    end
+  end
+
   setup do
     @d = Dummy.new
   end
@@ -436,4 +451,559 @@ class Dummy < Fluent::Plugin::TestBase
       end
     end
   end
+
+  sub_test_case "ExponentialBackOff_ScenarioTests" do
+    data("Simple timeout", {
+      timeout: 100, max_steps: nil, max_interval: nil, use_sec: false, sec_thres: 0.8, wait: 1, backoff_base: 2,
+      expected: [
+        RetryRecord.new(1, 1, false),
+        RetryRecord.new(2, 3, false),
+        RetryRecord.new(3, 7, false),
+        RetryRecord.new(4, 15, false),
+        RetryRecord.new(5, 31, false),
+        RetryRecord.new(6, 63, false),
+        RetryRecord.new(7, 100, false),
+      ],
+    })
+    data("Simple timeout with secondary", {
+      timeout: 100, max_steps: nil, max_interval: nil, use_sec: true, sec_thres: 0.8, wait: 1, backoff_base: 2,
+      expected: [
+        RetryRecord.new(1, 1, false),
+        RetryRecord.new(2, 3, false),
+        RetryRecord.new(3, 7, false),
+        RetryRecord.new(4, 15, false),
+        RetryRecord.new(5, 31, false),
+        RetryRecord.new(6, 63, false),
+        RetryRecord.new(7, 80, true),
+        RetryRecord.new(8, 81, true),
+        RetryRecord.new(9, 83, true),
+        RetryRecord.new(10, 87, true),
+        RetryRecord.new(11, 95, true),
+        RetryRecord.new(12, 100, true),
+      ],
+    })
+    data("Simple timeout with custom wait and backoff_base", {
+      timeout: 1000, max_steps: nil, max_interval: nil, use_sec: false, sec_thres: 0.8, wait: 2, backoff_base: 3,
+      expected: [
+        RetryRecord.new(1, 2, false),
+        RetryRecord.new(2, 8, false),
+        RetryRecord.new(3, 26, false),
+        RetryRecord.new(4, 80, false),
+        RetryRecord.new(5, 242, false),
+        RetryRecord.new(6, 728, false),
+        RetryRecord.new(7, 1000, false),
+      ],
+    })
+    data("Simple timeout with custom wait and backoff_base and secondary", {
+      timeout: 1000, max_steps: nil, max_interval: nil, use_sec: true, sec_thres: 0.8, wait: 2, backoff_base: 3,
+      expected: [
+        RetryRecord.new(1, 2, false),
+        RetryRecord.new(2, 8, false),
+        RetryRecord.new(3, 26, false),
+        RetryRecord.new(4, 80, false),
+        RetryRecord.new(5, 242, false),
+        RetryRecord.new(6, 728, false),
+        RetryRecord.new(7, 800, true),
+        RetryRecord.new(8, 802, true),
+        RetryRecord.new(9, 808, true),
+        RetryRecord.new(10, 826, true),
+        RetryRecord.new(11, 880, true),
+        RetryRecord.new(12, 1000, true),
+      ],
+    })
+    data("Default timeout", {
+      timeout: 72*3600, max_steps: nil, max_interval: nil, use_sec: false, sec_thres: 0.8, wait: 1, backoff_base: 2,
+      expected: [
+        RetryRecord.new(1, 1, false),
+        RetryRecord.new(2, 3, false),
+        RetryRecord.new(3, 7, false),
+        RetryRecord.new(4, 15, false),
+        RetryRecord.new(5, 31, false),
+        RetryRecord.new(6, 63, false),
+        RetryRecord.new(7, 127, false),
+        RetryRecord.new(8, 255, false),
+        RetryRecord.new(9, 511, false),
+        RetryRecord.new(10, 1023, false),
+        RetryRecord.new(11, 2047, false),
+        RetryRecord.new(12, 4095, false),
+        RetryRecord.new(13, 8191, false),
+        RetryRecord.new(14, 16383, false),
+        RetryRecord.new(15, 32767, false),
+        RetryRecord.new(16, 65535, false),
+        RetryRecord.new(17, 131071, false),
+        RetryRecord.new(18, 259200, false),
+      ],
+    })
+    data("Default timeout with secondary", {
+      timeout: 72*3600, max_steps: nil, max_interval: nil, use_sec: true, sec_thres: 0.8, wait: 1, backoff_base: 2,
+      expected: [
+        RetryRecord.new(1, 1, false),
+        RetryRecord.new(2, 3, false),
+        RetryRecord.new(3, 7, false),
+        RetryRecord.new(4, 15, false),
+        RetryRecord.new(5, 31, false),
+        RetryRecord.new(6, 63, false),
+        RetryRecord.new(7, 127, false),
+        RetryRecord.new(8, 255, false),
+        RetryRecord.new(9, 511, false),
+        RetryRecord.new(10, 1023, false),
+        RetryRecord.new(11, 2047, false),
+        RetryRecord.new(12, 4095, false),
+        RetryRecord.new(13, 8191, false),
+        RetryRecord.new(14, 16383, false),
+        RetryRecord.new(15, 32767, false),
+        RetryRecord.new(16, 65535, false),
+        RetryRecord.new(17, 131071, false),
+        RetryRecord.new(18, 207360, true),
+        RetryRecord.new(19, 207361, true),
+        RetryRecord.new(20, 207363, true),
+        RetryRecord.new(21, 207367, true),
+        RetryRecord.new(22, 207375, true),
+        RetryRecord.new(23, 207391, true),
+        RetryRecord.new(24, 207423, true),
+        RetryRecord.new(25, 207487, true),
+        RetryRecord.new(26, 207615, true),
+        RetryRecord.new(27, 207871, true),
+        RetryRecord.new(28, 208383, true),
+        RetryRecord.new(29, 209407, true),
+        RetryRecord.new(30, 211455, true),
+        RetryRecord.new(31, 215551, true),
+        RetryRecord.new(32, 223743, true),
+        RetryRecord.new(33, 240127, true),
+        RetryRecord.new(34, 259200, true),
+      ],
+    })
+    data("Default timeout with secondary and custom threshold", {
+      timeout: 72*3600, max_steps: nil, max_interval: nil, use_sec: true, sec_thres: 0.5, wait: 1, backoff_base: 2,
+      expected: [
+        RetryRecord.new(1, 1, false),
+        RetryRecord.new(2, 3, false),
+        RetryRecord.new(3, 7, false),
+        RetryRecord.new(4, 15, false),
+        RetryRecord.new(5, 31, false),
+        RetryRecord.new(6, 63, false),
+        RetryRecord.new(7, 127, false),
+        RetryRecord.new(8, 255, false),
+        RetryRecord.new(9, 511, false),
+        RetryRecord.new(10, 1023, false),
+        RetryRecord.new(11, 2047, false),
+        RetryRecord.new(12, 4095, false),
+        RetryRecord.new(13, 8191, false),
+        RetryRecord.new(14, 16383, false),
+        RetryRecord.new(15, 32767, false),
+        RetryRecord.new(16, 65535, false),
+        RetryRecord.new(17, 129600, true),
+        RetryRecord.new(18, 129601, true),
+        RetryRecord.new(19, 129603, true),
+        RetryRecord.new(20, 129607, true),
+        RetryRecord.new(21, 129615, true),
+        RetryRecord.new(22, 129631, true),
+        RetryRecord.new(23, 129663, true),
+        RetryRecord.new(24, 129727, true),
+        RetryRecord.new(25, 129855, true),
+        RetryRecord.new(26, 130111, true),
+        RetryRecord.new(27, 130623, true),
+        RetryRecord.new(28, 131647, true),
+        RetryRecord.new(29, 133695, true),
+        RetryRecord.new(30, 137791, true),
+        RetryRecord.new(31, 145983, true),
+        RetryRecord.new(32, 162367, true),
+        RetryRecord.new(33, 195135, true),
+        RetryRecord.new(34, 259200, true),
+      ],
+    })
+    data("Simple max_steps", {
+      timeout: 72*3600, max_steps: 10, max_interval: nil, use_sec: false, sec_thres: 0.8, wait: 1, backoff_base: 2,
+      expected: [
+        RetryRecord.new(1, 1, false),
+        RetryRecord.new(2, 3, false),
+        RetryRecord.new(3, 7, false),
+        RetryRecord.new(4, 15, false),
+        RetryRecord.new(5, 31, false),
+        RetryRecord.new(6, 63, false),
+        RetryRecord.new(7, 127, false),
+        RetryRecord.new(8, 255, false),
+        RetryRecord.new(9, 511, false),
+        RetryRecord.new(10, 1023, false),
+      ],
+    })
+    data("Simple max_steps with secondary", {
+      timeout: 72*3600, max_steps: 10, max_interval: nil, use_sec: true, sec_thres: 0.8, wait: 1, backoff_base: 2,
+      expected: [
+        RetryRecord.new(1, 1, false),
+        RetryRecord.new(2, 3, false),
+        RetryRecord.new(3, 7, false),
+        RetryRecord.new(4, 15, false),
+        RetryRecord.new(5, 31, false),
+        RetryRecord.new(6, 63, false),
+        RetryRecord.new(7, 127, false),
+        RetryRecord.new(8, 255, false),
+        RetryRecord.new(9, 511, false),
+        RetryRecord.new(10, 818, true),
+      ],
+    })
+    data("Simple interval", {
+      timeout: 72*3600, max_steps: nil, max_interval: 3600, use_sec: false, sec_thres: 0.8, wait: 1, backoff_base: 2,
+      expected: [
+        RetryRecord.new(1, 1, false),
+        RetryRecord.new(2, 3, false),
+        RetryRecord.new(3, 7, false),
+        RetryRecord.new(4, 15, false),
+        RetryRecord.new(5, 31, false),
+        RetryRecord.new(6, 63, false),
+        RetryRecord.new(7, 127, false),
+        RetryRecord.new(8, 255, false),
+        RetryRecord.new(9, 511, false),
+        RetryRecord.new(10, 1023, false),
+        RetryRecord.new(11, 2047, false),
+        RetryRecord.new(12, 4095, false),
+        RetryRecord.new(13, 7695, false),
+        RetryRecord.new(14, 11295, false),
+        RetryRecord.new(15, 14895, false),
+        RetryRecord.new(16, 18495, false),
+        RetryRecord.new(17, 22095, false),
+        RetryRecord.new(18, 25695, false),
+        RetryRecord.new(19, 29295, false),
+        RetryRecord.new(20, 32895, false),
+        RetryRecord.new(21, 36495, false),
+        RetryRecord.new(22, 40095, false),
+        RetryRecord.new(23, 43695, false),
+        RetryRecord.new(24, 47295, false),
+        RetryRecord.new(25, 50895, false),
+        RetryRecord.new(26, 54495, false),
+        RetryRecord.new(27, 58095, false),
+        RetryRecord.new(28, 61695, false),
+        RetryRecord.new(29, 65295, false),
+        RetryRecord.new(30, 68895, false),
+        RetryRecord.new(31, 72495, false),
+        RetryRecord.new(32, 76095, false),
+        RetryRecord.new(33, 79695, false),
+        RetryRecord.new(34, 83295, false),
+        RetryRecord.new(35, 86895, false),
+        RetryRecord.new(36, 90495, false),
+        RetryRecord.new(37, 94095, false),
+        RetryRecord.new(38, 97695, false),
+        RetryRecord.new(39, 101295, false),
+        RetryRecord.new(40, 104895, false),
+        RetryRecord.new(41, 108495, false),
+        RetryRecord.new(42, 112095, false),
+        RetryRecord.new(43, 115695, false),
+        RetryRecord.new(44, 119295, false),
+        RetryRecord.new(45, 122895, false),
+        RetryRecord.new(46, 126495, false),
+        RetryRecord.new(47, 130095, false),
+        RetryRecord.new(48, 133695, false),
+        RetryRecord.new(49, 137295, false),
+        RetryRecord.new(50, 140895, false),
+        RetryRecord.new(51, 144495, false),
+        RetryRecord.new(52, 148095, false),
+        RetryRecord.new(53, 151695, false),
+        RetryRecord.new(54, 155295, false),
+        RetryRecord.new(55, 158895, false),
+        RetryRecord.new(56, 162495, false),
+        RetryRecord.new(57, 166095, false),
+        RetryRecord.new(58, 169695, false),
+        RetryRecord.new(59, 173295, false),
+        RetryRecord.new(60, 176895, false),
+        RetryRecord.new(61, 180495, false),
+        RetryRecord.new(62, 184095, false),
+        RetryRecord.new(63, 187695, false),
+        RetryRecord.new(64, 191295, false),
+        RetryRecord.new(65, 194895, false),
+        RetryRecord.new(66, 198495, false),
+        RetryRecord.new(67, 202095, false),
+        RetryRecord.new(68, 205695, false),
+        RetryRecord.new(69, 209295, false),
+        RetryRecord.new(70, 212895, false),
+        RetryRecord.new(71, 216495, false),
+        RetryRecord.new(72, 220095, false),
+        RetryRecord.new(73, 223695, false),
+        RetryRecord.new(74, 227295, false),
+        RetryRecord.new(75, 230895, false),
+        RetryRecord.new(76, 234495, false),
+        RetryRecord.new(77, 238095, false),
+        RetryRecord.new(78, 241695, false),
+        RetryRecord.new(79, 245295, false),
+        RetryRecord.new(80, 248895, false),
+        RetryRecord.new(81, 252495, false),
+        RetryRecord.new(82, 256095, false),
+        RetryRecord.new(83, 259200, false),
+      ],
+    })
+    data("Simple interval with secondary", {
+      timeout: 72*3600, max_steps: nil, max_interval: 3600, use_sec: true, sec_thres: 0.8, wait: 1, backoff_base: 2,
+      expected: [
+        RetryRecord.new(1, 1, false),
+        RetryRecord.new(2, 3, false),
+        RetryRecord.new(3, 7, false),
+        RetryRecord.new(4, 15, false),
+        RetryRecord.new(5, 31, false),
+        RetryRecord.new(6, 63, false),
+        RetryRecord.new(7, 127, false),
+        RetryRecord.new(8, 255, false),
+        RetryRecord.new(9, 511, false),
+        RetryRecord.new(10, 1023, false),
+        RetryRecord.new(11, 2047, false),
+        RetryRecord.new(12, 4095, false),
+        RetryRecord.new(13, 7695, false),
+        RetryRecord.new(14, 11295, false),
+        RetryRecord.new(15, 14895, false),
+        RetryRecord.new(16, 18495, false),
+        RetryRecord.new(17, 22095, false),
+        RetryRecord.new(18, 25695, false),
+        RetryRecord.new(19, 29295, false),
+        RetryRecord.new(20, 32895, false),
+        RetryRecord.new(21, 36495, false),
+        RetryRecord.new(22, 40095, false),
+        RetryRecord.new(23, 43695, false),
+        RetryRecord.new(24, 47295, false),
+        RetryRecord.new(25, 50895, false),
+        RetryRecord.new(26, 54495, false),
+        RetryRecord.new(27, 58095, false),
+        RetryRecord.new(28, 61695, false),
+        RetryRecord.new(29, 65295, false),
+        RetryRecord.new(30, 68895, false),
+        RetryRecord.new(31, 72495, false),
+        RetryRecord.new(32, 76095, false),
+        RetryRecord.new(33, 79695, false),
+        RetryRecord.new(34, 83295, false),
+        RetryRecord.new(35, 86895, false),
+        RetryRecord.new(36, 90495, false),
+        RetryRecord.new(37, 94095, false),
+        RetryRecord.new(38, 97695, false),
+        RetryRecord.new(39, 101295, false),
+        RetryRecord.new(40, 104895, false),
+        RetryRecord.new(41, 108495, false),
+        RetryRecord.new(42, 112095, false),
+        RetryRecord.new(43, 115695, false),
+        RetryRecord.new(44, 119295, false),
+        RetryRecord.new(45, 122895, false),
+        RetryRecord.new(46, 126495, false),
+        RetryRecord.new(47, 130095, false),
+        RetryRecord.new(48, 133695, false),
+        RetryRecord.new(49, 137295, false),
+        RetryRecord.new(50, 140895, false),
+        RetryRecord.new(51, 144495, false),
+        RetryRecord.new(52, 148095, false),
+        RetryRecord.new(53, 151695, false),
+        RetryRecord.new(54, 155295, false),
+        RetryRecord.new(55, 158895, false),
+        RetryRecord.new(56, 162495, false),
+        RetryRecord.new(57, 166095, false),
+        RetryRecord.new(58, 169695, false),
+        RetryRecord.new(59, 173295, false),
+        RetryRecord.new(60, 176895, false),
+        RetryRecord.new(61, 180495, false),
+        RetryRecord.new(62, 184095, false),
+        RetryRecord.new(63, 187695, false),
+        RetryRecord.new(64, 191295, false),
+        RetryRecord.new(65, 194895, false),
+        RetryRecord.new(66, 198495, false),
+        RetryRecord.new(67, 202095, false),
+        RetryRecord.new(68, 205695, false),
+        RetryRecord.new(69, 207360, true),
+        RetryRecord.new(70, 207361, true),
+        RetryRecord.new(71, 207363, true),
+        RetryRecord.new(72, 207367, true),
+        RetryRecord.new(73, 207375, true),
+        RetryRecord.new(74, 207391, true),
+        RetryRecord.new(75, 207423, true),
+        RetryRecord.new(76, 207487, true),
+        RetryRecord.new(77, 207615, true),
+        RetryRecord.new(78, 207871, true),
+        RetryRecord.new(79, 208383, true),
+        RetryRecord.new(80, 209407, true),
+        RetryRecord.new(81, 211455, true),
+        RetryRecord.new(82, 215055, true),
+        RetryRecord.new(83, 218655, true),
+        RetryRecord.new(84, 222255, true),
+        RetryRecord.new(85, 225855, true),
+        RetryRecord.new(86, 229455, true),
+        RetryRecord.new(87, 233055, true),
+        RetryRecord.new(88, 236655, true),
+        RetryRecord.new(89, 240255, true),
+        RetryRecord.new(90, 243855, true),
+        RetryRecord.new(91, 247455, true),
+        RetryRecord.new(92, 251055, true),
+        RetryRecord.new(93, 254655, true),
+        RetryRecord.new(94, 258255, true),
+        RetryRecord.new(95, 259200, true),
+      ],
+    })
+    data("Max_steps and max_interval", {
+      timeout: 72*3600, max_steps: 30, max_interval: 3600, use_sec: false, sec_thres: 0.8, wait: 1, backoff_base: 2,
+      expected: [
+        RetryRecord.new(1, 1, false),
+        RetryRecord.new(2, 3, false),
+        RetryRecord.new(3, 7, false),
+        RetryRecord.new(4, 15, false),
+        RetryRecord.new(5, 31, false),
+        RetryRecord.new(6, 63, false),
+        RetryRecord.new(7, 127, false),
+        RetryRecord.new(8, 255, false),
+        RetryRecord.new(9, 511, false),
+        RetryRecord.new(10, 1023, false),
+        RetryRecord.new(11, 2047, false),
+        RetryRecord.new(12, 4095, false),
+        RetryRecord.new(13, 7695, false),
+        RetryRecord.new(14, 11295, false),
+        RetryRecord.new(15, 14895, false),
+        RetryRecord.new(16, 18495, false),
+        RetryRecord.new(17, 22095, false),
+        RetryRecord.new(18, 25695, false),
+        RetryRecord.new(19, 29295, false),
+        RetryRecord.new(20, 32895, false),
+        RetryRecord.new(21, 36495, false),
+        RetryRecord.new(22, 40095, false),
+        RetryRecord.new(23, 43695, false),
+        RetryRecord.new(24, 47295, false),
+        RetryRecord.new(25, 50895, false),
+        RetryRecord.new(26, 54495, false),
+        RetryRecord.new(27, 58095, false),
+        RetryRecord.new(28, 61695, false),
+        RetryRecord.new(29, 65295, false),
+        RetryRecord.new(30, 68895, false),
+      ],
+    })
+    data("Max_steps and max_interval with secondary", {
+      timeout: 72*3600, max_steps: 30, max_interval: 3600, use_sec: true, sec_thres: 0.8, wait: 1, backoff_base: 2,
+      expected: [
+        RetryRecord.new(1, 1, false),
+        RetryRecord.new(2, 3, false),
+        RetryRecord.new(3, 7, false),
+        RetryRecord.new(4, 15, false),
+        RetryRecord.new(5, 31, false),
+        RetryRecord.new(6, 63, false),
+        RetryRecord.new(7, 127, false),
+        RetryRecord.new(8, 255, false),
+        RetryRecord.new(9, 511, false),
+        RetryRecord.new(10, 1023, false),
+        RetryRecord.new(11, 2047, false),
+        RetryRecord.new(12, 4095, false),
+        RetryRecord.new(13, 7695, false),
+        RetryRecord.new(14, 11295, false),
+        RetryRecord.new(15, 14895, false),
+        RetryRecord.new(16, 18495, false),
+        RetryRecord.new(17, 22095, false),
+        RetryRecord.new(18, 25695, false),
+        RetryRecord.new(19, 29295, false),
+        RetryRecord.new(20, 32895, false),
+        RetryRecord.new(21, 36495, false),
+        RetryRecord.new(22, 40095, false),
+        RetryRecord.new(23, 43695, false),
+        RetryRecord.new(24, 47295, false),
+        RetryRecord.new(25, 50895, false),
+        RetryRecord.new(26, 54495, false),
+        RetryRecord.new(27, 55116, true),
+        RetryRecord.new(28, 55117, true),
+        RetryRecord.new(29, 55119, true),
+        RetryRecord.new(30, 55123, true),
+      ],
+    })
+    data("Max_steps and max_interval with timeout", {
+      timeout: 10000, max_steps: 30, max_interval: 1000, use_sec: false, sec_thres: 0.8, wait: 1, backoff_base: 2,
+      expected: [
+        RetryRecord.new(1, 1, false),
+        RetryRecord.new(2, 3, false),
+        RetryRecord.new(3, 7, false),
+        RetryRecord.new(4, 15, false),
+        RetryRecord.new(5, 31, false),
+        RetryRecord.new(6, 63, false),
+        RetryRecord.new(7, 127, false),
+        RetryRecord.new(8, 255, false),
+        RetryRecord.new(9, 511, false),
+        RetryRecord.new(10, 1023, false),
+        RetryRecord.new(11, 2023, false),
+        RetryRecord.new(12, 3023, false),
+        RetryRecord.new(13, 4023, false),
+        RetryRecord.new(14, 5023, false),
+        RetryRecord.new(15, 6023, false),
+        RetryRecord.new(16, 7023, false),
+        RetryRecord.new(17, 8023, false),
+        RetryRecord.new(18, 9023, false),
+        RetryRecord.new(19, 10000, false),
+      ],
+    })
+    data("Max_steps and max_interval with timeout and secondary", {
+      timeout: 10000, max_steps: 30, max_interval: 1000, use_sec: true, sec_thres: 0.8, wait: 1, backoff_base: 2,
+      expected: [
+        RetryRecord.new(1, 1, false),
+        RetryRecord.new(2, 3, false),
+        RetryRecord.new(3, 7, false),
+        RetryRecord.new(4, 15, false),
+        RetryRecord.new(5, 31, false),
+        RetryRecord.new(6, 63, false),
+        RetryRecord.new(7, 127, false),
+        RetryRecord.new(8, 255, false),
+        RetryRecord.new(9, 511, false),
+        RetryRecord.new(10, 1023, false),
+        RetryRecord.new(11, 2023, false),
+        RetryRecord.new(12, 3023, false),
+        RetryRecord.new(13, 4023, false),
+        RetryRecord.new(14, 5023, false),
+        RetryRecord.new(15, 6023, false),
+        RetryRecord.new(16, 7023, false),
+        RetryRecord.new(17, 8000, true),
+        RetryRecord.new(18, 8001, true),
+        RetryRecord.new(19, 8003, true),
+        RetryRecord.new(20, 8007, true),
+        RetryRecord.new(21, 8015, true),
+        RetryRecord.new(22, 8031, true),
+        RetryRecord.new(23, 8063, true),
+        RetryRecord.new(24, 8127, true),
+        RetryRecord.new(25, 8255, true),
+        RetryRecord.new(26, 8511, true),
+        RetryRecord.new(27, 9023, true),
+        RetryRecord.new(28, 10000, true),
+      ],
+    })
+    test "exponential backoff with senario" do |data|
+      print_for_debug = false # change this value true if need to see msg always.
+      trying_count = 1000 # just for avoiding infinite loop
+
+      retry_records = []
+      msg = ""
+
+      s = @d.retry_state_create(
+        :t15, :exponential_backoff, data[:wait], data[:timeout],
+        max_steps: data[:max_steps], max_interval: data[:max_interval],
+        secondary: data[:use_sec], secondary_threshold: data[:sec_thres],
+        backoff_base: data[:backoff_base], randomize: false
+      )
+      override_current_time(s, s.start)
+
+      retry_count = 0
+      trying_count.times do
+        next_elapsed = (s.next_time - s.start).to_i
+
+        msg << "step: #{s.steps}, next: #{next_elapsed}s (#{next_elapsed / 3600}h)\n"
+
+        # Wait until next time to trigger the next retry
+        override_current_time(s, s.next_time)
+
+        # Retry will be triggered at this point.
+        retry_count += 1
+        rec = RetryRecord.new(retry_count, next_elapsed, s.secondary?)
+        retry_records.append(rec)
+        msg << "[#{next_elapsed}s elapsed point] #{retry_count}th-Retry(#{s.secondary? ? "SEC" : "PRI"}) is triggered.\n"
+
+        # Update retry statement
+        if s.limit?
+          msg << "--- Reach limit of timeout. ---\n"
+          break
+        end
+
+        s.step
+
+        if s.limit_step?
+          msg << "--- Reach limit of max step. ---\n"
+          break
+        end
+      end
+
+      assert_equal(data[:expected], retry_records, msg)
+
+      print(msg) if print_for_debug
+    end
+  end
 end