rantav

#import <Foundation/Foundation.h>

@class ASINetworkQueue, Catalog, ASIHTTPRequest;

@interface DownloadCatalogOperation : NSOperation {
  /* queue for downloading many assets in paralel */
  ASINetworkQueue* networkQueue;
  
  NSString* tmpDownloadPath;
  Catalog* catalog;

rantav

506543691 [qtp2136389305-1580] ERROR org.codehaus.groovy.grails.web.errors.GrailsExceptionResolver  - org.eclipse.jetty.io.EofException
org.eclipse.jetty.io.RuntimeIOException: org.eclipse.jetty.io.EofException
	at org.eclipse.jetty.io.UncheckedPrintWriter.setError(UncheckedPrintWriter.java:107)
	at org.eclipse.jetty.io.UncheckedPrintWriter.write(UncheckedPrintWriter.java:234)
	at tmp_jetty_0_0_0_0_8080_org_linkedin_glu_console_webapp_3_2_0_war__console_any__webapp_WEB_INF_grails_app_views_layouts_main_gsp.run(tmp_jetty_0_0_0_0_8080_org_linkedin_glu_console_webapp_3_2_0_war__console_any__webapp_WEB_INF_grails_app_views_layouts_main_gsp:190)
	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:534)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1351)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1322)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1322)
	at org.eclipse.jetty.se

rantav

#import <UIKit/UIKit.h>
#import "AQGridViewCell.h"

@interface SpringBoardIconCell : AQGridViewCell
{
    UIImageView * _iconView;
  UILabel* indexLabel;
}

- (id) initWithFrame:(CGRect)frame reuseIdentifier:(NSString*)reuseIdentifier;

rantav

In mongodb it's easy to make at upsert, meaning update-or-insert by calling

db.collection.update({criteria}, {updated fields}, true)

The third parameter means - insert a new document if the document doesn't exist yet. So, for example, the following will insert a new document for the user if there's no document for that user yet, and will update it if it already exists:

 db.users.update({user_id: '1234'}, {user_id: '1234', name: 'Ran'}, true)

rantav

A few show tricks to find slow queries in mongodb

Enable profiling

First, you have to enable profiling

> db.setProfilingLevel(1)

Now let it run for a while. It collects the slow queries ( > 100ms) into a capped collections, so queries go in and if it's full, old queries go out, so don't be surprised that it's a moving target...

rantav

// Old style mongodb group and a bit more of javascript to complete the task (Array.sort and Array.slice)
db.Session.group({
  key: {user: true}, 
  cond: {
    serviceId: '888', 
    end: {$gte: ISODate('2012-08-30T00:00:00Z'), $lte: ISODate('2012-08-31T00:00:00Z')}, 
    start: {$lte: ISODate('2012-08-31T00:00:00Z')}
  }, 
  initial: {durationSeconds: 0}, 
  reduce: function(obj, prev) {prev.durationSeconds += obj.durationSeconds;}

rantav

When using newrelic in java, it isn't obvious how to mavenize things. Newrelic has two java jars: newrelic.jar and newrelic-api.jar. There's also another newrelic.yaml of course. For development you need the api.jar in your classpath. In production you want the api jar in the classpath, but also newrelic.jar as an agent. Newrelic have a good explanation about how to set up newrelic.jar as an agent but they don't have anything regarding how to develop and get the api jar in place using maven, so here goes...

Add the repository:

<repositories>
  <repository>
    <id>newrelic</id>

newrelic

rantav

require 'speaker'
require 'israel'

module Israel
  module DevOps
    def call_for_papers(speaker, subject)
      # Speakers should apply for the call for papers if they have talks on the subjects of Continuous Deployment of DevOps tooling
      # Assuming they are available Jan 13.
      apply(spekaer) if ["Continuous Deployment Case Studies", "DevOps tools"].include(subject) and speaker.available?(Date.new(2013,1,13))
    end

rantav

[119832.732086] BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
[119832.732111] IP: [<ffffffff81053527>] pick_next_task_fair+0xa7/0x1a0
[119832.732124] PGD 1cee6f067 PUD 1cd5e7067 PMD 0 
[119832.732132] Oops: 0000 [#1] SMP 
[119832.732137] last sysfs file: /sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_map
[119832.732145] CPU 1 
[119832.732147] Modules linked in: acpiphp raid456 async_pq async_xor xor async_memcpy async_raid6_recov raid10 raid6_pq async_tx raid1 raid0 multipath linear
[119832.732172] 
[119832.732177] Pid: 7896, comm: chef-client Not tainted 2.6.38-8-virtual #42-Ubuntu  
[119832.732186] RIP: e030:[<ffffffff81053527>]  [<ffffffff81053527>] pick_next_task_fair+0xa7/0x1a0

rantav

{ robot: 
     { name: 'bot',
       brain: [Object],
       alias: false,
       adapter: [Object],
       commands: [Object],
       Response: [Function: Response],
       listeners: [Circular],
       loadPaths: [Object],
       enableSlash: undefined,