Merge pull request #491 from raytung/feat/out_rdkafka2_unknown_partition

feat(out_rdkafka2): add parameter `use_default_for_unknown_partition_error`

Author: ashie

README.md

@@ -510,7 +510,8 @@ You need to install rdkafka gem.
       partition_key_key     (string) :default => 'partition_key'
       message_key_key       (string) :default => 'message_key'
       default_topic         (string) :default => nil
-      use_default_for_unknown_topic (bool) :default => false
+      use_default_for_unknown_topic           (bool) :default => false
+      use_default_for_unknown_partition_error (bool) :default => false
       default_partition_key (string) :default => nil
       default_message_key   (string) :default => nil
       exclude_topic_key     (bool) :default => false

lib/fluent/plugin/out_rdkafka2.rb

@@ -66,6 +66,7 @@ class Fluent::Rdkafka2Output < Output
     config_param :default_topic, :string, :default => nil,
                  :desc => "Default output topic when record doesn't have topic field"
     config_param :use_default_for_unknown_topic, :bool, :default => false, :desc => "If true, default_topic is used when topic not found"
+    config_param :use_default_for_unknown_partition_error, :bool, :default => false, :desc => "If true, default_topic is used when received unknown_partition error"
     config_param :message_key_key, :string, :default => 'message_key', :desc => "Field for kafka message key"
     config_param :default_message_key, :string, :default => nil
     config_param :partition_key, :string, :default => 'partition', :desc => "Field for kafka partition"
@@ -234,8 +235,8 @@ def add(level, message = nil)
       @rdkafka = Rdkafka::Config.new(config)
 
       if @default_topic.nil?
-        if @use_default_for_unknown_topic
-          raise Fluent::ConfigError, "default_topic must be set when use_default_for_unknown_topic is true"
+        if @use_default_for_unknown_topic || @use_default_for_unknown_partition_error
+          raise Fluent::ConfigError, "default_topic must be set when use_default_for_unknown_topic or use_default_for_unknown_partition_error is true"
         end
         if @chunk_keys.include?(@topic_key) && !@chunk_key_tag
           log.warn "Use '#{@topic_key}' field of event record for topic but no fallback. Recommend to set default_topic or set 'tag' in buffer chunk keys like <buffer #{@topic_key},tag>"
@@ -504,6 +505,16 @@ def enqueue_with_retry(producer, topic, record_buf, message_key, partition, head
               actual_topic = @default_topic
               retry
             end
+            raise e
+          # https://github.com/confluentinc/librdkafka/blob/c282ba2423b2694052393c8edb0399a5ef471b3f/src/rdkafka.h#L305
+          # RD_KAFKA_RESP_ERR__UNKNOWN_PARTITION
+          when :unknown_partition
+            if @use_default_for_unknown_partition_error && actual_topic != @default_topic
+              log.debug "failed writing to topic '#{actual_topic}' with error '#{e.to_s}'. Writing message to topic '#{@default_topic}'"
+              actual_topic = @default_topic
+              retry
+            end
+
             raise e
           else
             raise e