Copyright © 2014 Splunk Inc. 
Splunking the JVM 
Damien Dallimore 
Dev Evangelist , CSO Office @ Splunk
Disclaimer 
During the course of this presentation, we may make forward looking statements regarding future events or the 
expected performance of the company. We caution you that such statements reflect our current expectations and 
estimates based on factors currently known to us and that actual events or results could differ materially. For important 
factors that may cause actual results to differ from those contained in our forward-looking statements, please review 
our filings with the SEC. The forward-looking statements made in the this presentation are being made as of the time 
and date of its live presentation. If reviewed after its live presentation, this presentation may not contain current or 
accurate information. We do not assume any obligation to update any forward looking statements we may make. In 
addition, any information about our roadmap outlines our general product direction and is subject to change at any 
time without notice. It is for informational purposes only and shall not, be incorporated into any contract or other 
commitment. Splunk undertakes no obligation either to develop the features or functionality described or to include 
any such feature or functionality in a future release. 
2
3 
From Middle Earth 
Make Splunk Apps & Add-ons 
JVM background
4
apps.splunk.com 
github.com/damiendallimore 
5
What is this JVM thing ?
JVM = Java Virtual Machine 
First appeared in the early 90’s 
Now the dominant runtime for enterprise 
applications 
Application Servers Enterprise Service Buses Databases 
NoSQL Distributed Big Data Web Servers 
Directory Servers Search Engines Build Systems 
Gaming Platforms Trading Systems Reservation Systems 
Core Banking Messaging Infrastructure Proprietary Systems 
7
8
Many JVM Variants 
Oracle Hotspot 
OpenJDK 
Oracle JRockit 
9 
IBM J9 
Azul Zing 
More or less the same. OpenJDK 
is reference impl for Java 7/8 
Getting merged into Hotspot 
Commercial alternatives
JVMs are here to stay 
It’s not just about the “J” 
Big Data frameworks 
You should care about getting insights into your 
JVM data 
10
Getting at the data
Data Sources 
Logs 
Developers 
JMX (Java Management Extensions) 
Instrumentation Agents 
Operating System 
Distributed Communications 
12
Log Data
Standard Log Files 
Oct 21, 2013 4:42:15 PM org.apache.catalina.startup.Catalina load 
INFO: Initialization processed in 1153 ms 
Oct 21, 2013 4:42:15 PM org.apache.catalina.core.StandardService startInternal 
INFO: Starting service Catalina 
Application logs that are part of the product 
Developer logs for any code that was deployed 
14 
Written to local disk or network storage
Garbage Collector Logs 
54.736: [Full GC 54.737: 
[Tenured: 172798K->18092K(174784K), 2.3792658 secs] 257598K->18092K(259584K), 
[Perm : 20476K->20476K(20480K)], 2.4715398 secs] [Times: user=0.56 sys=0.05, real=0.07 secs] 
Generated by way of arguments passed to the JVM at startup 
15 
-verbose:gc 
-Xloggc:/home/damien/jvm_logs/gc.log 
-XX:+PrintGC 
-XX:+PrintGCTimeStamps 
-XX:+PrintGCDetails
SplunkJavaLogging 
Sometimes you can’t write to file or deploy a UF 
Appenders for Java Util Logging , Log4J , Logback 
Simply add a logging appender to your logging configuration file 
16
LogBack Appender Example 
17
Code 
18
Best practice semantic format 
2012-08-07 15:54:06:644+1200 name="Failed Login" event_id=”12345" app="myapp" user="jane” 
19
Better Exception Logging 
20
Easier to work with in Splunk 
21
Splunk SDK for Java 
Use the SDK from any JVM Language , Java / Groovy / Scala etc…. 
Send log events via REST , UDP or TCP directly to Splunk from your code 
Spring Integration Adaptors available on Github 
22 
SDK available from dev.splunk.com
Using Java SDK 
23
Using Spring 
24
JMX
JMX = Java Management Extensions 
Monitor JVM via MBean attributes , operations and notifications 
JVM MBeans 
Vendor MBeans 
Custom Coded MBeans 
26
Browse MBeans with JConsole 
27
Getting this data into Splunk 
Runs on all supported Splunk platforms 
Works with all main JVM variants 
100% Free and Open Source 
28
Simple to Configure 
29
Many Connectivity Options 
Let’s look at this Splunk App in action 
30
31 
This is great for monitoring a 
single JVM……
But what if we have dozens , hundreds , even thousands ? 
32
Multiple jmxserver elements per configuration file 
33
Multiple configuration files per Splunk Instance 
34
But stacking vertically will only get you so far 
35
Go horizontal to achieve real scale 
36 
Indexer Cluster 
UFs with JMX Mod Input 
Monitored JVMs
In my experience , the data sources shown so far will be 
thorough enough for most of your JVM monitoring use cases. 
But what if you want to go deeper ? 
37
Instrumentation 
Agents
SplunkJavaAgent 
Dynamic Byte Code Injection Agent for JVMs 
No need to change any code to get APM level insights 
This is all you pass to the JVM at startup : 
-javaagent:splunkagent.jar 
39
What raw metrics can you get ? 
40 
Bytecode Injection 
• class loading 
• method execution 
• method timings 
• method call stack 
• caught & uncaught exceptions 
JMX 
• running in local in-memory mode 
Binary HPROF Memory dumps decoded in text 
• no more static hprof dumps and then loading into another Mem Analysis tool
Simple Configuration File 
41
42
Raw events streamed into Splunk 
43
Search with Splunk 
44
Reveal APM insights 
45
Operating System
The JVM executes as a process 
Let’s see what the host Operating System can tell us : top 
External programs that provide additional JVM insights : jstat 
Index this data in Splunk and correlate 
47
top 
48
49
jstat 
50
51
Distributed 
Communications
Valuable data flows in & out of JVMs 
53 
Messaging 
Capture packets off the wire
Build a Splunk App !
Opportunity 
Reuse some of the data collection approaches in this presentation 
and build out a specific JVM app 
55 
Publish it on apps.splunk.com 
Make some money 
Generate publicity for yourself / your company 
Generate sales leads 
Sell more Splunk licenses if you are also a partner 
Do it because you love community collaboration 
Become my beer buddy for life
Some JVM App Ideas 
Splunk for JBoss 
Splunk for Tomcat 
Splunk for Solr 
Splunk for Cassandra 
Splunk for “Apache Project” 
I am here to help you 
56
THANK YOU 
@damiendallimore 
ddallimore@splunk.com
Questions ?

Splunk Conf 2014 - Splunking the Java Virtual Machine

  • 1.
    Copyright © 2014Splunk Inc. Splunking the JVM Damien Dallimore Dev Evangelist , CSO Office @ Splunk
  • 2.
    Disclaimer During thecourse of this presentation, we may make forward looking statements regarding future events or the expected performance of the company. We caution you that such statements reflect our current expectations and estimates based on factors currently known to us and that actual events or results could differ materially. For important factors that may cause actual results to differ from those contained in our forward-looking statements, please review our filings with the SEC. The forward-looking statements made in the this presentation are being made as of the time and date of its live presentation. If reviewed after its live presentation, this presentation may not contain current or accurate information. We do not assume any obligation to update any forward looking statements we may make. In addition, any information about our roadmap outlines our general product direction and is subject to change at any time without notice. It is for informational purposes only and shall not, be incorporated into any contract or other commitment. Splunk undertakes no obligation either to develop the features or functionality described or to include any such feature or functionality in a future release. 2
  • 3.
    3 From MiddleEarth Make Splunk Apps & Add-ons JVM background
  • 4.
  • 5.
  • 6.
    What is thisJVM thing ?
  • 7.
    JVM = JavaVirtual Machine First appeared in the early 90’s Now the dominant runtime for enterprise applications Application Servers Enterprise Service Buses Databases NoSQL Distributed Big Data Web Servers Directory Servers Search Engines Build Systems Gaming Platforms Trading Systems Reservation Systems Core Banking Messaging Infrastructure Proprietary Systems 7
  • 8.
  • 9.
    Many JVM Variants Oracle Hotspot OpenJDK Oracle JRockit 9 IBM J9 Azul Zing More or less the same. OpenJDK is reference impl for Java 7/8 Getting merged into Hotspot Commercial alternatives
  • 10.
    JVMs are hereto stay It’s not just about the “J” Big Data frameworks You should care about getting insights into your JVM data 10
  • 11.
  • 12.
    Data Sources Logs Developers JMX (Java Management Extensions) Instrumentation Agents Operating System Distributed Communications 12
  • 13.
  • 14.
    Standard Log Files Oct 21, 2013 4:42:15 PM org.apache.catalina.startup.Catalina load INFO: Initialization processed in 1153 ms Oct 21, 2013 4:42:15 PM org.apache.catalina.core.StandardService startInternal INFO: Starting service Catalina Application logs that are part of the product Developer logs for any code that was deployed 14 Written to local disk or network storage
  • 15.
    Garbage Collector Logs 54.736: [Full GC 54.737: [Tenured: 172798K->18092K(174784K), 2.3792658 secs] 257598K->18092K(259584K), [Perm : 20476K->20476K(20480K)], 2.4715398 secs] [Times: user=0.56 sys=0.05, real=0.07 secs] Generated by way of arguments passed to the JVM at startup 15 -verbose:gc -Xloggc:/home/damien/jvm_logs/gc.log -XX:+PrintGC -XX:+PrintGCTimeStamps -XX:+PrintGCDetails
  • 16.
    SplunkJavaLogging Sometimes youcan’t write to file or deploy a UF Appenders for Java Util Logging , Log4J , Logback Simply add a logging appender to your logging configuration file 16
  • 17.
  • 18.
  • 19.
    Best practice semanticformat 2012-08-07 15:54:06:644+1200 name="Failed Login" event_id=”12345" app="myapp" user="jane” 19
  • 20.
  • 21.
    Easier to workwith in Splunk 21
  • 22.
    Splunk SDK forJava Use the SDK from any JVM Language , Java / Groovy / Scala etc…. Send log events via REST , UDP or TCP directly to Splunk from your code Spring Integration Adaptors available on Github 22 SDK available from dev.splunk.com
  • 23.
  • 24.
  • 25.
  • 26.
    JMX = JavaManagement Extensions Monitor JVM via MBean attributes , operations and notifications JVM MBeans Vendor MBeans Custom Coded MBeans 26
  • 27.
    Browse MBeans withJConsole 27
  • 28.
    Getting this datainto Splunk Runs on all supported Splunk platforms Works with all main JVM variants 100% Free and Open Source 28
  • 29.
  • 30.
    Many Connectivity Options Let’s look at this Splunk App in action 30
  • 31.
    31 This isgreat for monitoring a single JVM……
  • 32.
    But what ifwe have dozens , hundreds , even thousands ? 32
  • 33.
    Multiple jmxserver elementsper configuration file 33
  • 34.
    Multiple configuration filesper Splunk Instance 34
  • 35.
    But stacking verticallywill only get you so far 35
  • 36.
    Go horizontal toachieve real scale 36 Indexer Cluster UFs with JMX Mod Input Monitored JVMs
  • 37.
    In my experience, the data sources shown so far will be thorough enough for most of your JVM monitoring use cases. But what if you want to go deeper ? 37
  • 38.
  • 39.
    SplunkJavaAgent Dynamic ByteCode Injection Agent for JVMs No need to change any code to get APM level insights This is all you pass to the JVM at startup : -javaagent:splunkagent.jar 39
  • 40.
    What raw metricscan you get ? 40 Bytecode Injection • class loading • method execution • method timings • method call stack • caught & uncaught exceptions JMX • running in local in-memory mode Binary HPROF Memory dumps decoded in text • no more static hprof dumps and then loading into another Mem Analysis tool
  • 41.
  • 42.
  • 43.
    Raw events streamedinto Splunk 43
  • 44.
  • 45.
  • 46.
  • 47.
    The JVM executesas a process Let’s see what the host Operating System can tell us : top External programs that provide additional JVM insights : jstat Index this data in Splunk and correlate 47
  • 48.
  • 49.
  • 50.
  • 51.
  • 52.
  • 53.
    Valuable data flowsin & out of JVMs 53 Messaging Capture packets off the wire
  • 54.
  • 55.
    Opportunity Reuse someof the data collection approaches in this presentation and build out a specific JVM app 55 Publish it on apps.splunk.com Make some money Generate publicity for yourself / your company Generate sales leads Sell more Splunk licenses if you are also a partner Do it because you love community collaboration Become my beer buddy for life
  • 56.
    Some JVM AppIdeas Splunk for JBoss Splunk for Tomcat Splunk for Solr Splunk for Cassandra Splunk for “Apache Project” I am here to help you 56
  • 57.
    THANK YOU @damiendallimore ddallimore@splunk.com
  • 58.

Editor's Notes

  • #3 Legal disclaimer
  • #4 From Auckland Dev evang , ex customer 5th Conf Make Apps , Cut code Through enterprise Java background in many verticals , enterprise and non enterprise Java and other JVM langs
  • #5 Everything 100% open source use , reuse , whatever. Collaborate Community answers.splunk.com for support is best
  • #8 JVM is a runtime for code that gets compiled to bytecode and executed. Not natively. But can JIT. So performance is good now. Circa 1991, Dr. James Gosling at Sun started developing a technology for next generation smart devices/appliances “Green” became “Oak” which became “Java” Java 1.0 first appeared in January 1996. The JVM is a virtual machine that runs programs that are compiled into Java bytecode Available for many hardware and software platforms 17 years later , the JVM has evolved from a consumer device technology, to a browser oriented technology with the explosion of the web , to now becoming deeply rooted in the enterprise software landscape on the server side and in the cloud Overcame some limitatons on C/C++ Language changes , generics , annotations , lambda’s , streams , default methods GC , JIT , bytecode , write once run anywhere
  • #9 Ask crowd about JVM experience : Devs Operations Have no idea but might after this preso
  • #10 Jrockit and hotspot code being integrated Openjdk closely linked to hotspot , Oracle JDK has a few other proprietary add-ons above. Open JDK is the Java reference impl Zing is commercial
  • #11 Groovy , Scala , Clojure , JS , the JVM is evolving with the changing landscape of enterprise software From app servers in the 00’s to Big Data frameworks today Hadoop , Cassandra, 1000’s of nodes The JVM footprint cross cuts the data centre and represents a massive source of valuable machine data Large scale Application/Web Server clusters Hadoop & Cassandra Node topologies in the 100’s and in some cases 1000’s Segway into JVM Data
  • #15 Monitor with a UF = best practice
  • #16 JVM generated logs by way of options
  • #17 Try to use a UF if at all possible Utility classes for formatting log events Configurable in memory buffer to handle network outages
  • #18 TCP and REST Appenders
  • #19 SplunkLogEvent will log in best practive semantic format
  • #22 index=main sourcetype=log4j2 | makemv delim="," stacktrace_elements | table _time throwable_message throwable_class stacktrace_elements
  • #23 What if you can’t use logging appenders etc… Well , then you have to get down and dirty with your code !
  • #27 Majority of useful data for monitoring will come from this layer Open and easily extensible Developers can simply create new MBeans Vendor products(JBoss, Cassandra, Hadoop etc..) ship with thorough MBean coverage, not MIBs
  • #28 JConsole to Browse Mbeans Enable your target JVM’s remote JMX interface , test connectivity with JConsole
  • #29 Splunkcowboy.com for demo
  • #30 As many config files as you want Can make output CIM compliant
  • #31 Also MX4j connectivity
  • #37 Run Splunk UF locally with target JVM.Can connect use remote JMX interface or direct process attachment. Each tier scales out horizontally. Can overcome firewall issues that are sometimes inherent with Java RMI Deploy Splunk for JMX components and configurations with Splunk Deployment Server, Puppet or Chef. More than just jvm as bottleneck , also have stdin/out and Splunk indexing pipeline
  • #40 Appdynamics have an integration
  • #41 Hprof : Binary JVM dumps that allow for deeper JVM resource inspection Typical use case is diagnosing memory issues after JVM crashes with java.lang.OutOfMemoryError
  • #45 sourcetype=splunk_java_agent name=method* | transaction appName,appID,threadID,className,methodName startswith=method_entered endswith=method_exited | stats min(duration) as "Min Execution Time" max(duration) as "Max Execution Time" avg(duration) as "Avg Execution Time" count as "Total Calls" sum(duration) as "Cumulative Execution Time" by className,methodName
  • #48 Correlate this OS data across your JVM and Application events ie: your JVM may have hung because of CPU starvation caused by some other process thrashing Could even go lower if running virtual and get the VM/Hypervisor data
  • #51 Created a wrapper script to dynamically get the PID of the Java process
  • #52 Custom handlers for pre-processing and reformatting if you want
  • #54 Not going into details here , there are other sessions you can attend.
  • #56 ie: reuse the JMX Modular input