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 :). 

Comments

Post a Comment

Popular posts from this blog

Haproxy and tomcat JSESSIONID

One of the biggest problems I have been trying to solve at our startup is to put our tomcat nodes in HA mode. Right now if a customer comes, he lands on to a node and remains there forever. This has two major issues: 1) We have to overprovision each node with ability to handle worse case capacity. 2) If two or three high profile customers lands on to same node then we need to move them manually. 3) We need to cut over new nodes and we already have over 100+ nodes.  Its a pain managing these nodes and I waste lot of my time in chasing node specific issues. I loath when I know I have to chase this env issue. I really hate human intervention as if it were up to me I would just automate thing and just enjoy the fruits of automation and spend quality time on major issues rather than mundane task,call me lazy but thats a good quality. So Finally now I am at a stage where I can put nodes behing HAProxy in QA env. today we were testing the HA config and first problem I immediat...
Post a Comment
Read more

Spring 3.2 quartz 2.1 Jobs added with no trigger must be durable.

I am trying to enable HA on nodes and in that process I found that in a two test node setup a job that has a frequency of 10 sec was running into deadlock. So I tried upgrading from Quartz 1.8 to 2.1 by following the migration guide but I ran into an exception that says "Jobs added with no trigger must be durable.". After looking into spring and Quartz code I figured out that now Quartz is more strict and earlier the scheduler.addJob had a replace parameter which if passed to true would skip the durable check, in latest quartz this is fixed but spring hasnt caught up to this. So what do you do, well I jsut inherited the factory and set durability to true and use that public class DurableJobDetailFactoryBean extends JobDetailFactoryBean {     public DurableJobDetailFactoryBean() {         setDurability(true);     } } and used this instead of JobDetailFactoryBean in the spring bean definition     <bean i...
7 comments
Read more

RabbitMQ java clients for beginners

Here is a sample of a consumer and producer example for RabbitMQ. The steps are Download Erlang Download Rabbit MQ Server Download Rabbit MQ Java client jars Compile 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 http://blogs.digitar.com/jjww/2009/01/rabbits-and-warrens/ +++++++++++++++++RabbitMQProducer.java+++++++++++++++++++++++++++ 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("127.0.0.1"); factory.se...
23 comments
Read more