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

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…

Logging to Graphite monitoring tool from java

We use Graphite as a tool for monitoring some stats and watch trends. A requirement is to monitor impact of new releases as build is deployed to app nodes to see if things like
1) Has the memcache usage increased.
2) Has the no of Java exceptions went up.
3) Is the app using more tomcat threads.
Here is a screenshot

We changed the installer to log a deploy event when a new build is deployed. I wrote a simple spring bean to log graphite events using java. Logging to graphite is easy, all you need to do is open a socket and send lines of events.
import org.slf4j.Logger;import org.slf4j.LoggerFactory; import java.io.OutputStreamWriter; import java.io.Writer; import java.net.Socket; import java.util.HashMap; import java.util.Map; public class GraphiteLogger { private static final Logger logger = LoggerFactory.getLogger(GraphiteLogger.class); private String graphiteHost; private int graphitePort; public String getGraphiteHost() { return graphiteHost; } public void setGraphite…

Jersey posting multipart data

This took me sometime to figure out mostly it was because I was only including jersey-multipart-1.6.jar but I was not including mimepull-1.3.jar.

So the intent is to upload a file using REST api and we need pass meta attributes in addition to uploading the file. Also the intent is to stream the file instead of first storing it on the local disk. Here is some sample code.
@Path("/upload-service") public class UploadService { @Context protected HttpServletResponse response; @Context protected HttpServletRequest request; @POST @Consumes(MediaType.MULTIPART_FORM_DATA) @Produces(MediaType.APPLICATION_JSON) public String uploadFile(@PathParam("fileName") final String fileName, @FormDataParam("workgroupId") String workgroupId, @FormDataParam("userId") final int userId, @FormDataParam("content") final InputStream content) throws JSONException { //.......Upload the file to S3 or netapp or any storage service } }
Now to tes…