Skip to main content

Building reusable tools saves precious time in future

I hate cases when I had made a code fix but the code fix is going live in 4 days and customer cant wait for the fix. Now you have to go and fix the data manually or give some workaround.  Anyways today ran into an issue where due to some recent code change a memcache key was not getting flushed and the  code fix for that is supposed to go live in 3 days. But a production support  guy called me to fix it for customer and I can understand frustration on part of customer. So the choices were:

1) Ask the production support guy to flush the key in all memcached instances with help of ops.
2) Manually go myself and flush the key. This could take anywhere from 10-15 min plus its boring doing data cleanup.
3)Flush the entire memcached cluster. This is a big NO NO.

So I was about to go on path #2 and realized that there is a internal REST API that the production support guy can call to flush arbitary key from memcached. Hurray I just told him what keys to flush and he knew how to call such apis.  So Thanks to whoever wrote that internal api thinking about its future use and making it generic, it saved me some time :). 


Popular posts from this blog

RabbitMQ java clients for beginners

Here is a sample of a consumer and producer example for RabbitMQ. The steps are
Download ErlangDownload Rabbit MQ ServerDownload Rabbit MQ Java client jarsCompile and run the below two class and you are done.
This sample create a Durable Exchange, Queue and a Message. You will have to start the consumer first before you start the for the first time.

For more information on AMQP, Exchanges, Queues, read this excellent tutorial
import com.rabbitmq.client.Connection; import com.rabbitmq.client.Channel; import com.rabbitmq.client.*; public class RabbitMQProducer { public static void main(String []args) throws Exception { ConnectionFactory factory = new ConnectionFactory(); factory.setUsername("guest"); factory.setPassword("guest"); factory.setVirtualHost("/"); factory.setHost(""); factory.setPort(5672); Conne…

Spring query timeout or transaction timeout

If you are using spring to manage transactions then you can specify default transaction timeout using

    <bean id="transactionManager"
        <property name="dataSource" ref="dataSource" />
        <property name="defaultTimeout" value="30" /> <!--30 sec--->             

or you can override the timeout in the annotation

    @Transactional(readOnly = false, timeout=30)

or if you are doing it programatic transactions then you can do

DataSourceTransactionManager transactionManager = new DataSourceTransactionManager(dataSource);

 or you can override the timeout for one particular transaction

TransactionTemplate transactionTemplate = new TransactionTemplate();

Python adding pid file

I have a thumbnail generator that launches multiple processes and the correct way to shut it down is to send kill -HUP to the parent process. To automate I had to write a pid file from python, it was a piece of cake
def writePidFile(): pid = str(os.getpid()) f = open('', 'w') f.write(pid) f.close()