Troubleshooting Live Java Web Applications

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Troubleshooting Live Java Web ApplicationsBy Ashley Puls

Sunday, September 8, 13


Troubleshooting

Location and eliminate sources of trouble

Determine and settle problems

A systematic approach to solving problems quickly and efficiently

A logical process of elimination to identify the true source of the problem


How To Become A Good Troubleshooter

Practice makes perfect

Images From: http://www.tennismindgame.com/image-files/topspin-tennis-serve.jpg


http://www.tennismindgame.com/image-files/topspin-tennis-serve.jpg


How To Become A Good Troubleshooter

Practice makes perfect

Images From: http://www.tennismindgame.com/image-files/topspin-tennis-serve.jpg, http://blogs.telerik.com/images/default-source/jeff-fritz/toolbox.jpg?sfvrsn=0

Have a good set of tools




Outline

examine a web application with multiple performance problems

troubleshoot the problems using several tools

talk about the pros and cons of each tool


STEP 1: WE NEED AN APPLICATION


The Application

Dear Developer,

I had some engineers develop “Running Central” to search for runners, races, and training teams. Can you please keep the site running?

Sincerely,Max SiegelCEO of USA Track and Field

Image From: http://www.sportsbusinessdaily.com/Journal/Issues/2012/06/18/Leagues-and-Governing-Bodies/~/media/8C99287D3B0E4784932EE3BF049E7DA9.ashx


http://www.sportsbusinessdaily.com/Journal/Issues/2012/06/18/Leagues-and-Governing-Bodies/~/media/8C99287D3B0E4784932EE3BF049E7DA9.ashx

http://www.sportsbusinessdaily.com/Journal/Issues/2012/06/18/Leagues-and-Governing-Bodies/~/media/8C99287D3B0E4784932EE3BF049E7DA9.ashx

The Application

MySQL Database

hibernate

racerunners.war

jsp

Client

Client

Client

Servlet

Controller

Manager

Entities

Tomcat Application Server


WE HAVE OUR APPLICATION

SHOULD WE JUST JUMP INTO TROUBLESHOOTING?

Image From: http://toosoxy.files.wordpress.com/2011/04/cliff.jpg


http://toosoxy.files.wordpress.com/2011/04/cliff.jpg

http://toosoxy.files.wordpress.com/2011/04/cliff.jpg

What Is Trouble?

Image From: http://1.bp.blogspot.com/-_LgC3yz9w4w/T4eI--IcvxI/AAAAAAAAA-o/VLdqkxyQpgg/s400/computerFire.jpg


http://1.bp.blogspot.com/-_LgC3yz9w4w/T4eI--IcvxI/AAAAAAAAA-o/VLdqkxyQpgg/s400/computerFire.jpg

http://1.bp.blogspot.com/-_LgC3yz9w4w/T4eI--IcvxI/AAAAAAAAA-o/VLdqkxyQpgg/s400/computerFire.jpg

Site InaccessibleWhat Is Trouble?


Site Inaccessible

ExceptionsIn Logs

What Is Trouble?


Site Inaccessible

ExceptionsIn Logs

Loading Slowly

What Is Trouble?


What Is Normal?

Images From: http://espn.go.com/mlb/statistics, http://www.franklinbaseball.com/pros/american-league/central/miguel-cabrera


http://espn.go.com/mlb/statistics

http://espn.go.com/mlb/statistics

http://www.franklinbaseball.com/pros/american-league/central/miguel-cabrera

http://www.franklinbaseball.com/pros/american-league/central/miguel-cabrera

Errorserrors within application

Application Response Time

time per request

Database Response Time

time per request

Thread Stateactive thread states

Garbage Collectiontime spent in GC

Memory Allocationheap and PermGen

What Are The Stats?


How To Gather The Stats

Logs

core JDK tools

Application Performance Monitoring Tools (APM)

Profiler

JMX Metrics

Framework/App Server Monitoring Tools


Tools Overview Installation Is It Free Include With JDK

Logs

App Server Monitoring

New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Basic Information

Basic information about each tool


Tools App Response Time

DB Response Time Error Info Thread Info GC Memory

Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool

What data does each tool provide?


LETS TALK TO SOME OF OUR USERS AND START

TROUBLESHOOTING


Image From: http://resources0.news.com.au/images/2012/08/10/1226447/688548-usain-bolt.jpg


http://resources0.news.com.au/images/2012/08/10/1226447/688548-usain-bolt.jpg


Image From: http://resources0.news.com.au/images/2012/08/10/1226447/688548-usain-bolt.jpg

Usain Bolt : Six Time Olympic Champion




I was looking for a 5K race on your site,

but it was loading like I was on a 56k

Image From: http://static.guim.co.uk/sys-images/Guardian/Pix/pictures/2012/8/9/1344533810934/f582144a-9dd2-44ed-9828-0ec1f5f768a8-460.jpeg


http://static.guim.co.uk/sys-images/Guardian/Pix/pictures/2012/8/9/1344533810934/f582144a-9dd2-44ed-9828-0ec1f5f768a8-460.jpeg

http://static.guim.co.uk/sys-images/Guardian/Pix/pictures/2012/8/9/1344533810934/f582144a-9dd2-44ed-9828-0ec1f5f768a8-460.jpeg

LETS INVESTIGATE!


New Relic

Application Performance Monitoring (APM) tool that monitors web

apps, mobile apps, servers, and databases

Sign up and download agent from the New Relic Website



Logs


New Relic APM solution restart app with agent

basic features: yesadv features: no

no

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Basic Information






Error InformationSunday, September 8, 13


Error InformationSunday, September 8, 13


Heap Memory


Heap Memory

Non-Heap Memory


Garbage Collection


Heap Memory Non- Heap Memory

Other

Class Instances

Arrays

Runtime constant pool

Interned Strings

Field and method data

JVM internal

structures

JVM Memory


Heap Memory Non- Heap Memory

Other

Common Memory Problems

Keeping references to old objects

Long term objects never cleaned up

Leaky class loaders

Interning an excessive number

of Strings






Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool


JMap

Prints the memory map of a Java process

Commands

jmap -heap JAVA_PID > /tmp/jmap.out

jmap -dump:file=/tmp/heap_dump.map JAVA_PID



Logs




no

YourKit

JVisualVm

JConsole

JMap/JHat prints memory map of Java process

no, attaches to running process yes yes

JStack

Basic Information


In a Terminal


In a Terminal


The File


The File

Heap Memory


The File

Heap Memory

Non-Heap Memory


The File

Heap Memory

Non-Heap Memory


In a Terminal


In a Terminal


The File


In a Terminal


In a Terminal


In a Terminal


In a Terminal


In a Terminal











Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool


YourKit

Profiler that provides in depth CPU, thread, and memory profiling

Get license key and download from YourKit Website



Logs




no

YourKit profiler maybe no, must pay for all features no

JVisualVm

JConsole



JStack

Basic Information





Thread Count


Thread Count

Error Rate


Thread Count

Error Rate



Thread Information


Thread Information


Non-Heap Memory

Heap Memory


Non-Heap Memory

Heap Memory


GC Information


Run a CPU profile


Application Response Times


Application Response Times


Database Response Times




Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool






/** * This service records stats on the cities and states queried by users when looking for races. The stats are * printed out to the log. */public class RaceStatsServiceImpl implements RaceStatsService {

private static final Logger LOGGER = LoggingUtils.getLogger(RunnerStatsServiceImpl.class.getName()); private static final Integer ONE = Integer.valueOf(1); private static final long DELAY = 1; /** Executer service which executes the thread that compiles stats and prints them to the log. */ private final ScheduledExecutorService scheduledExecutor; /** Holds the cities queried by users in the last minute. */ private final Map<String, Integer> citiesQueried; /** Holds the states queried in the last minute. */ private final Map<String, Integer> stateQueried;

public RaceStatsServiceImpl() { citiesQueried = new ConcurrentHashMap<String, Integer>(); stateQueried = new ConcurrentHashMap<String, Integer>(); // Calls the processor thread’s run method every minute scheduledExecutor = Executors.newSingleThreadScheduledExecutor(); scheduledExecutor.scheduleAtFixedRate(new Processor(), DELAY, DELAY, TimeUnit.MINUTES); }

/** * This should be called every time a city or state is used to search for races. * * @param city The city that was queried. * @param state The state that was queried. */ public void addLocation(String city, String state) { if (city != null && !city.isEmpty()) { addToMap(citiesQueried, city.trim()); } if (state != null && state.isEmpty()) { addToMap(stateQueried, state); } }






Two ConcurrentHashMaps








/** * Thread that runs periodically and reports the frequency that cities and states are queried to the log. */ private final class Processor extends Thread {

/** * Creates this Processor. */ public Processor() { super(); }

/** * Prints each city and state that was queried by a user since the Processor thread was last run. */ @Override public void run() { StringBuilder sb = new StringBuilder("(Race City Query:Count: "); Iterator<Entry<String, Integer>> cityIt = citiesQueried.entrySet().iterator(); Entry<String, Integer> current; while (cityIt.hasNext()) { current = cityIt.next(); sb.append(current.getKey()).append(":").append(current.getValue()).append(" "); }

sb.append("\nRace State Query:Count: "); Iterator<Entry<String, Integer>> stateIt = stateQueried.entrySet().iterator(); while (stateIt.hasNext()) { current = stateIt.next(); sb.append(current.getKey()).append(current.getValue()).append(" "); } LOGGER.log(Level.INFO, sb.toString()); } }






Processor is an inner class of RaceStatsServiceImpl






Processor is an inner class of RaceStatsServiceImpl



private final class Processor extends Thread {


/** * Prints each city and state that was queried by a user since the Processor thread was last run. */ @Override public void run() { StringBuilder sb = new StringBuilder("(Race City Query:Count: "); Iterator<Entry<String, Integer>> cityIt = citiesQueried.entrySet().iterator(); Entry<String, Integer> current; while (cityIt.hasNext()) { current = cityIt.next(); sb.append(current.getKey()).append(":").append(current.getValue()).append(" "); cityIt.remove(); }

sb.append("\nRace State Query:Count: "); Iterator<Entry<String, Integer>> stateIt = stateQueried.entrySet().iterator(); while (stateIt.hasNext()) { current = stateIt.next(); sb.append(current.getKey()).append(current.getValue()).append(" "); stateIt.remove(); } LOGGER.log(Level.INFO, sb.toString()); } }


SOLUTION

CLEAN UP MEMORY IN LONG RUNNING OBJECTS


AFTER THE FIX


The File


The File


Image From: http://news.images.itv.com/image/file/69820/article_9e6cab04948b5c33_1343574136_9j-4aaqsk.jpeg


http://news.images.itv.com/image/file/69820/article_9e6cab04948b5c33_1343574136_9j-4aaqsk.jpeg


Image From: http://news.images.itv.com/image/file/69820/article_9e6cab04948b5c33_1343574136_9j-4aaqsk.jpeg

Paula RadcliffeFemale Marathon World Record Holder




Image From: http://i3.manchestereveningnews.co.uk/incoming/article660410.ece/ALTERNATES/s615/C_71_article_1584722_image_list_image_list_item_0_image-660410.jpg

It was taking too long to find my fellow runners on

your site


http://i3.manchestereveningnews.co.uk/incoming/article660410.ece/ALTERNATES/s615/C_71_article_1584722_image_list_image_list_item_0_image-660410.jpg

http://i3.manchestereveningnews.co.uk/incoming/article660410.ece/ALTERNATES/s615/C_71_article_1584722_image_list_image_list_item_0_image-660410.jpg

LETS INVESTIGATE!


JVisualVM

Visual tool which provides heap dumps, memory leak information,

garbage collection monitoring, memory profiling, and CPU profiling

Attaches to local and remote running processes



Logs




no


JVisualVm profiler no yes yes

JConsole



JStack

Basic Information





GC Information


Memory Information

GC Information


Thread Information

Memory Information

GC Information


Thread Information

GC Information

Memory Information









Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool


Kill Dash 3

Provides the current stack trace for each thread in a local JVM (thread dump)

Available on linux and macs (ctrl+break on windows)

Command: kill -3 PID


JStack

Provides the current stack trace for each thread in a local or remote

JVM (thread dump)

Command: jstack -l JAVA_PID > /tmp/jstack.out



Logs


New Relic APM Solution restart app with agent


no



JConsole



JStack prints thread dump of Java process


Basic Information


In a Terminal


The File


The File




Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool


New Relic






Thread Count


Thread Count











Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool


/** * Stores stats on the last names of runners which have been queried. */public class RunnerStatsServiceImpl implements RunnerStatsService {

private static final Logger LOGGER = LoggingUtils.getLogger(RunnerStatsServiceImpl.class.getName()); private static final long DELAY = 1; /** Executor service which schedules the StatsProcessor thread to run every minute. */ private final ScheduledExecutorService scheduledExecutor; /** Stores the last name of queried runners. */ private final Queue<String> lastNamesQueried;

public RunnerStatsServiceImpl() { lastNamesQueried = new ArrayBlockingQueue<String>(100); // reports the metrics to the log every minute scheduledExecutor = Executors.newSingleThreadScheduledExecutor(); scheduledExecutor.scheduleAtFixedRate(new StatsProcessor(), DELAY, DELAY, TimeUnit.MINUTES); }

/** * Adds an entry in the stats. * * @param lastName A last name that was queried. */ public void addEntries(String lastName) {

if (lastName != null && !lastName.isEmpty()) { while (!lastNamesQueried.offer(lastName.trim())) { try { Thread.sleep(100); } catch (InterruptedException e) { // ignore this exception } } } }







Where the threads are sleeping








queue blocking at 100 strings








queue blocking at 100 strings


SOLUTION

DO NOT BLOCK THREADS


AFTER THE FIX


The File


The File

waiting for more requests to come in


Image From: http://www.webrun.com.br/multimidia/fotos/2011/20110926_175711_g.jpg


http://www.webrun.com.br/multimidia/fotos/2011/20110926_175711_g.jpg


Image From: http://www.webrun.com.br/multimidia/fotos/2011/20110926_175711_g.jpg

Patrick Makau Musyoki

Marathon World Record Holder




Image From: http://simonfreeman.co.uk/wp-content/uploads/2013/04/image-4.jpeg

I tried to look for marathons on your site but could not access it


http://simonfreeman.co.uk/wp-content/uploads/2013/04/image-4.jpeg

http://simonfreeman.co.uk/wp-content/uploads/2013/04/image-4.jpeg

LETS INVESTIGATE!


New Relic






JConsole

Graphical User Interface (GUI) which displays Java Management

Extension (JMX) metrics for a local or remote JVMs

JMX metrics should be enabled in your application server


Tools Overview Installation Cost Include With JDK

Logs




no



JConsole JMX metrics no yes yes





Basic Information


Tools Overview Installation Cost Include With JDK

Logs




no








Basic Information


JMX

MBean MBean MBean

Managed beans (mbeans) represent resources. They are a remotely accessible interface into a resource that provides stats and can be used to manipulate the resource.

Examples include applications, JDBC drivers, garbage collection mechanisms, and thread pools.


JMX

MBean MBean MBean

MBean Server

The mbean server acts as the intermediary between the mbeans and the application requesting the information.

Mbeans can be created, registered, and deleted through the server.


JMX

MBean MBean MBean

MBean Server

Connector Adaptor

JConsole





Memory Information


Memory InformationThread Information


Memory InformationThread Information





JVM specific mbeans


Tomcat Application Server mbeans

JVM specific mbeans








Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool


CAN YOU DO THIS IN JVISUALVM?









Tomcat Application Server mbeans

JVM specific mbeans




The File vi tomcat/config/server.xml






THREAD POOLS NEEDED TO BE TUNED

SOLUTION


What Should Be The Size Of The Pool?

• If the pool size is too small, then requests back up

Image From: http://terrortrendsbulletin.files.wordpress.com/2012/11/airport-security-lines1.jpg


http://terrortrendsbulletin.files.wordpress.com/2012/11/airport-security-lines1.jpg

http://terrortrendsbulletin.files.wordpress.com/2012/11/airport-security-lines1.jpg


• If the pool size is too large, then system resources

might become exhausted





Image From: http://static.ddmcdn.com/gif/airport-security-detector1.jpg


http://static.ddmcdn.com/gif/airport-security-detector1.jpg





Images From: http://static.ddmcdn.com/gif/airport-security-detector1.jpg, http://graphics8.nytimes.com/images/2012/10/07/travel/07GETAWAY_SPAN/07GETAWAY_SPAN-articleLarge.jpg







• Pool size limiting factors

– The amount of memory

• In Java 6, the default thread stack size on Sparc is 512k for the

32-bit VM and 1024k for the 64-bit VM

Hotspot Thread Stack Numbers: http://www.oracle.com/technetwork/java/hotspotfaq-138619.html


http://www.oracle.com/technetwork/java/hotspotfaq-138619.html



• Pool size limiting factors

– The amount of memory

• In Java 6, the default thread stack size on Sparc is 512k for the

32-bit VM and 1024k for the 64-bit VM

–The number of CPUs

• Context switching could become an issue

Hotspot Thread Stack Numbers: http://www.oracle.com/technetwork/java/hotspotfaq-138619.html




Little’s Law

= the average response time for a request

= the approximate size for your pool

= the average arrival rate of requests


AFTER THE FIX




Image From: http://coedmagazine.files.wordpress.com/2012/08/carmelita-jeter-7.jpg


http://coedmagazine.files.wordpress.com/2012/08/carmelita-jeter-7.jpg


Image From: http://coedmagazine.files.wordpress.com/2012/08/carmelita-jeter-7.jpg

Carmelita JeterFastest Woman Alive in the

100 meter sprint




Image From: http://www4.pictures.zimbio.com/gi/Carmelita+Jeter+Olympics+Day+14+Athletics+G48Jqgqo2nml.jpg

My team’s 4x100 time is faster than your website.

Get that fixed!


http://www4.pictures.zimbio.com/gi/Carmelita+Jeter+Olympics+Day+14+Athletics+G48Jqgqo2nml.jpg

http://www4.pictures.zimbio.com/gi/Carmelita+Jeter+Olympics+Day+14+Athletics+G48Jqgqo2nml.jpg

LETS INVESTIGATE!


Application Performance Monitoring

Most application servers have an admin console which provides some

monitoring information

The quality of the admin console varies significantly between products



Logs

App Server Monitoring admin console, varies between app servers sometimes yes no



no








Basic Information



Memory Information





Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool


New Relic












Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool


Logs

Application, server, and database logs provide information developers

consider important for evaluating the status of the application

The quality of the logs varies significantly between products

Tools like Splunk and Loggly can help analyze logs



Logs application, app server, framework, and db logs no yes yes

App Server Monitoring admin console, varies between app servers sometimes yes no



no



JConsole m no yes yes





Basic Information


The Application Log


The Application Log

Varies between applications


The Application Log

Varies between applications


The Application Log

Spring AOP


The Application Log

Create The Aspect


The Application Log

Create The Aspect


The Application Log

Create The Aspect


The Application Log

Create The Aspect


The Application Log

Create The Aspect


Application Server Log



Information on requests

host_access_log



Information on requests

host_access_log



This is what the app server or framework developer considered important.

Catalina.out




Catalina.out




applicationContext.xml












Catalina.out


MySQL Log


MySQL Log

The only log on by default is the error log.


MySQL Log

You can turn on the slow sql log.

Add the following to your /etc/my.cnf


MySQL Log




MySQL Log



Query Time Rows Examined


MySQL Log



Query Time Rows Examined




Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool


In a Terminal


In a Terminal


In a Terminal


In a Terminal


In a Terminal


In a Terminal


In a Terminal


In a Terminal


In a Terminal


In a Terminal


USE INDEXES APPROPRIATELY

SOLUTION


AFTER THE FIX


In a Terminal


In a Terminal




Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool




Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool




Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool




Logs


New Relic

YourKit

JVisualVm

JConsole

JMap/JHat

JStack

Data In Tool


Tools Application Response Time

LogsJConsole


JVisualVm - No Profiler

JStack

New Relic

Your Kit - No Profiler

JMap

Your Kit - With Profiler

JVisualVM - With Profiler

Basic Information

What is the impact of each tool?



Logs NoneJConsole None

App Server Monitoring None

JVisualVm - No Profiler None

JStack Low

New Relic Low

Your Kit - No Profiler High

JMap High

Your Kit - With Profiler Very High

JVisualVM - With Profiler Very High

Basic Information






JStack Low

New Relic Low


JMap High



Basic Information

Use In Production






JStack Low

New Relic Low


JMap High



Basic Information

Use In Production

Use In Development






JStack Low

New Relic Low


JMap High



Basic Information

Use In Production

Use In Development


Tools Overview Installation Is It Free Include With JDK For Prod

Logs application, app server, framework, and db logs no yes yes yes


admin console, varies between app servers sometimes yes no yes


basic features: yes

adv features: no

no yes

YourKit Profiler maybe no, must pay for all features no no

JVisualVm Profiler no yes yes basic: yesprofile: no

JConsole JMX Metrics no yes yes yes


No, attaches to running process yes yes no


no, attaches to running process yes yes yes

Basic Information


Tools Overview Installation Is It Free Include With JDK For Prod

Logs application, app server, framework, and db logs no yes yes yes


admin console, varies between app servers sometimes yes no yes


basic features: yes

adv features: no

no yes

YourKit Profiler maybe no, must pay for all features no no

JVisualVm Profiler no yes yes basic: yesprofile: no

JConsole JMX Metrics no yes yes yes


No, attaches to running process yes yes no


no, attaches to running process yes yes yes

Basic Information


Image From: http://www.tbkconsult.com/blog/wp-content/uploads/2011/07/Toolbox.jpg

I encourage you to add a new tool to your tool box


http://www.tbkconsult.com/blog/wp-content/uploads/2011/07/Toolbox.jpg


Image From: http://www.tbkconsult.com/blog/wp-content/uploads/2011/07/Toolbox.jpg

I encourage you to add a new tool to your tool box

Add the tool sooner rather than later




Image From: http://www.mediaemerging.com/wp-content/uploads/2010/11/Wrong-Tool-for-the-Job2.jpg

You should learn how to use the tools before you need them


http://www.mediaemerging.com/wp-content/uploads/2010/11/Wrong-Tool-for-the-Job2.jpg

http://www.mediaemerging.com/wp-content/uploads/2010/11/Wrong-Tool-for-the-Job2.jpg

Images From: http://seattletimes.com/ABPub/2011/09/25/2016318932.jpg, http://static.guim.co.uk/sys-images/Sport/Pix/pictures/2007/12/08/PaulaRadcliffe_ap_SethWenig.jpg, http://www.runnersworld.com/sites/default/files/rw/Jeter-Carmelita-Happy-300x200.jpg, http://www.thefumble.com/sites/captainwag.com/files/wp-content/uploads/2012/08/BOLTBDAY.gif

WE WANT HAPPY USERS


http://seattletimes.com/ABPub/2011/09/25/2016318932.jpg

http://seattletimes.com/ABPub/2011/09/25/2016318932.jpg

http://static.guim.co.uk/sys-images/Sport/Pix/pictures/2007/12/08/PaulaRadcliffe_ap_SethWenig.jpg

http://static.guim.co.uk/sys-images/Sport/Pix/pictures/2007/12/08/PaulaRadcliffe_ap_SethWenig.jpg

http://www.runnersworld.com/sites/default/files/rw/Jeter-Carmelita-Happy-300x200.jpg




http://www.thefumble.com/sites/captainwag.com/files/wp-content/uploads/2012/08/BOLTBDAY.gif

http://www.thefumble.com/sites/captainwag.com/files/wp-content/uploads/2012/08/BOLTBDAY.gif

Learn More. Stay Connected.

Go try a new tool!

Talk to us on Twitter: @springcentralFind session replays on YouTube: spring.io/video


We are hiring: newrelic.com/jobs


http://newrelic.com/jobs

http://newrelic.com/jobs

http://futurestack.io


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Date post:	23-Jan-2015
Category:	Technology
Upload:	spring-io
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Troubleshooting Live Java Web Applications

Technology