解決方案寫在前面：./kafka-console-consumer.sh –topic xxxxxx –bootstrap-server localhost:9092 –max-messages 10 –from-beginning

業務線有使用 Kafka，有時想從 Kafka 里弄些資料出來做測試，但是 --from-beginning 就有點太多了，同時滿屏刷，不太好，如果有類似於 SQL 的 limit 關鍵字就好了。最後是執行 ./kafka-console-consumer.sh

# ./kafka-console-consumer.sh
The console consumer is
 
 a tool that reads data from Kafka and outputs it to standard output.
Option                                  Description                            
------                                  -----------                            
--blacklist <blacklist>                 Blacklist of topics to exclude from
 
    
                                          consumption.                         
--bootstrap-server <server to connect   REQUIRED (unless old consumer is       
  to>                                     used): The server to connect to.     
--consumer-property <consumer_prop>     A mechanism to
 
 pass user-defined       
                                          properties in the form key=value to  
                                          the consumer.                        
--consumer.config <config file>         Consumer config properties file. Note  
                                          that [consumer-property] takes       
                                          precedence over this config.         
--csv-reporter-enabled                  If set, the CSV metrics reporter will  
                                          be enabled                           
--delete-consumer-offsets               If specified, the consumer path in     
                                          zookeeper is deleted when starting up
--enable-systest-events                 Log lifecycle events of the consumer   
                                          in addition to logging consumed      
                                          messages. (This is specific for      
                                          system tests.)                       
--formatter <class>                     The name of a class to use for         
                                          formatting kafka messages for        
                                          display. (default: kafka.tools.      
                                          DefaultMessageFormatter)             
--from-beginning                        If the consumer does not already have  
                                          an established offset to consume     
                                          from, start with the earliest        
                                          message present in the log rather    
                                          than the latest message.             
--key-deserializer <deserializer for                                           
  key>                                                                         
--max-messages <Integer: num_messages>  The maximum number of messages to      
                                          consume before exiting. If not set,  
                                          consumption is continual.            
--metrics-dir <metrics directory>       If csv-reporter-enable is set, and     
                                          this parameter isset, the csv        
                                          metrics will be outputed here        
--new-consumer                          Use the new consumer implementation.   
                                          This is the default.                 
--offset <consume offset>               The offset id to consume from (a non-  
                                          negative number), or 'earliest'      
                                          which means from beginning, or       
                                          'latest' which means from end        
                                          (default: latest)                    
--partition <Integer: partition>        The partition to consume from.         
--property <prop>                       The properties to initialize the       
                                          message formatter.                   
--skip-message-on-error                 If there is an error when processing a 
                                          message, skip it instead of halt.    
--timeout-ms <Integer: timeout_ms>      If specified, exit if no message is    
                                          available for consumption for the    
                                          specified interval.                  
--topic <topic>                         The topic id to consume on.            
--value-deserializer <deserializer for                                         
  values>                                                                      
--whitelist <whitelist>                 Whitelist of topics to include for     
                                          consumption.                         
--zookeeper <urls>                      REQUIRED (only when using old          
                                          consumer): The connection string for 
                                          the zookeeper connection in the form 
                                          host:port. Multiple URLS can be      
                                          given to allow fail-over.    

注意到裡面有個 –max-messages，會只消費 N 條資料，如果配合 --from-beginning，就會消費最早 N 條資料。之後就可以愉快地玩耍了。
如果是消費之後到達的 N 條資訊後退出，不需要加 --from-beginning 就可以了。
路漫漫其修遠兮，慢慢加油！好記性不如爛鍵盤！