Skip to main content

Got first mysql table with 84M records

wow this is the first time I had scaled a database with 84M records in one table. Though I didn't expected it to grow this big but a weird customer behaviour where he had 17K versions of a file and he moved it 5K times. 17K version * 5K move=85M events generated in one shard in one table.

Within a month these will get purged as we retain last one month event, so table size will go down but it feels good that the system is behaving nice after adding the missing index on this 85M table, today its again sleeping like a baby.



Comments

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
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.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"
        class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource" />
        <property name="defaultTimeout" value="30" /> <!--30 sec--->             
    </bean>

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);
transactionManager.setDefaultTimeout(30);

 or you can override the timeout for one particular transaction

TransactionTemplate transactionTemplate = new TransactionTemplate();
transactionTemplate.setTimeout(30);

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('thumbnail_rabbit_consumer.pid', 'w') f.write(pid) f.close()