XAER_NOTA - DISTRIBUTED_LOCK_TIMEOUT

Several XAER_NOTA messages seen in the logs could be caused by not honoring:

DISTRIBUTED_LOCK_TIMEOUT (set on DB) > XA Transaction (connection) Timeout > WebLogic Server JTA timeout

netstat cheat sheet

Para ver conexiones tcp:

netstat -s -P tcp

ver un puerto en específico:

netstat –anp | grep puerto_admin

Mac:

netstat -an | grep -i 7001


----

A number of useful tools which can be used are netstat (to determine the number of sockets in TIME_WAIT state, for example by using, netstat –a | grep TIME_WAIT | wc –l) or iostat (to determine disk I/O on the operating system, for example, iostat 5 5). Note that iostat is part of the sysstat package, which can be installed by using: yum -y install sysstat.  
Networking linux:

https://upcloud.com/community/tutorials/troubleshoot-network-connectivity-linux-server/
https://geekflare.com/linux-networking-commands/
https://likegeeks.com/linux-network-commands/


 

Klondike Returns

Since 90s from college I read the old article of Martin Gardner from Scientific American.
This problem probably has been one of the most famous I have seen through the years, it appears with its own frequency.

With the original problem there are hundreds of solutions, some of them are

1. W W W E SW E NW SW NE NE NE SW SW SW NW
2. NW SE W SE SE W NW SW NE NE NE SW SW SW NW
3. N W E SW S E NW SW NE NE NE SW SW SW SE
4. NE W S SW S E NW SW NE NE NE SW SW SW SE
5. E W S SE S NW NW SW NE NE NE SW SW SW NW
6. SE W NW SE W W NW SW NE NE NE SW SW SW NW
7. S W E SW W NW SW NE NE NE SW SW SW NW


And with the troublesome fixed there are only two solutions:

SW SW NE NE NE SW SW SW NW
SW SW NE NE NE SW SW SW SE


I made Yet Another Search Program for it. where the troublesome 2 from Gardner article is verified, but I found a if we change (besides of the 2 mentioned) number 4 at (x,y) then there will be only one solution.

But there is a new probable modification I found to make the puzzle with an unique solution, which would be

Turing secret number

The secret Turing number: 885205232

As century of Turing ... birthday ? there are several events and commemorations...

This was revealed by Professor Knuth in the lecture in the UK .... twitter.

https://www-cs-faculty.stanford.edu/~knuth/news12.html

For the secret of the Turing number 885205232, see pages 45 and 53 of Selected Papers on Fun and Games. 

localstrings

WLS & classloading again...

Caused By: java.lang.IllegalArgumentException: com.sun.xml.internal.messaging.saaj.soap.LocalStrings != com.sun.xml.messaging.saaj.soap.LocalStrings

Goog Analysis : http://azagozdzinski.wordpress.com/2011/02/15/saaj-problem/

Eclipse Memory Analyzer

Eclipse MAT new version, and as usual I need to change "eclipse" .ini configuration:

./Contents/Eclipse/MemoryAnalyzer.ini

-startup
../Eclipse/plugins/org.eclipse.equinox.launcher_1.5.0.v20180512-1130.jar
--launcher.library
../Eclipse/plugins/org.eclipse.equinox.launcher.cocoa.macosx.x86_64_1.1.700.v20180518-1200
-vm
/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/bin
-data
/Users/German/tmp/workspace_mat
-vmargs
-Xmx5g 
-Dorg.eclipse.swt.internal.carbon.smallFonts
-XstartOnFirstThread

Disruptor OOM

Be careful with the Ring Buffer ;-)

- com.lmax.disruptor.RingBuffer

APM list

Based on Java Awesome, this is a simple list of Open Source APM:

• Pinpoint
• Zipkin
• Glowroot
• Jaeger (hawkular) *
• Kamon
• Stagemonitor
• jSonde (@deprecated?) *

-javaagent:/home/kaizen/pinpoint-agent-1.8.0-SNAPSHOT/pinpoint-bootstrap-1.8.0-SNAPSHOT.jar -Dpinpoint.agentId=WLS01 -Dpinpoint.applicationName=Sandbox

-javaagent:/home/kaizen/pinpoint-agent-1.8.0-SNAPSHOT/pinpoint-bootstrap-1.8.0-SNAPSHOT.jar -Dpinpoint.agentId=WLS02 -Dpinpoint.applicationName=Sandbox

admin.json 

  ],
  "web": {
    "port": 4011,
    "bindAddress": "0.0.0.0",
    "contextPath": "/",
    "sessionTimeoutMinutes": 30,
    "sessionCookieName": "GLOWROOT_SESSION_ID"
  },

-javaagent:/home/oracle/foobar/glowroot/glowroot.jar -Dglowroot.agent.id=WLSQux02

https://github.com/glowroot/glowroot/wiki/Agent-Installation-(with-Embedded-Collector)

Hadoop EDW 101

• Framework para trabajar con aplicaciones distribuidas en un ambiente de varios nodos para maneja de gran volumen de data
• Distribuido con gran tolerancia a la falla, escalable (HDFS)
• Usa modelo de programación MapReduce (procesamiento de big data, paralelo, distribuido, permite diferentes lenguajes)
• Bajo costo en los nodos por poder usar “commodity hardware”. Pudiendo guardar información por un periodo mas largo de tiempo con gran almacenamiento
• Buen rendimiento al evitar uso excesivo de networking
• Gran almacenamiento de data “cruda”, para ser procesado por Hadoop MapReduce o proyectos afines (Hive, Spark, Sqoop, etc.)
• Tiene perfil de ETL (sin ser uno con un gran performance), en donde puede tener procesamiento paralelo
• Convivencia con EDW, a través de Sqoop (xfr bulk data)
• Se puede ejecutar queries similares con el uso de Apache Hive que es un data-warehouse sobre Hadoop que sirve para hacer queries y análisis. (HiveQL, abstracción de SQL)
• Puede parsear diferentes tipos de inputs (web logs, IoT, etc.)
• No es un reemplazo directo de EDW, pero si en ciertas tareas pueden ser reemplazadas, así mejora el rendimiento
• Se puede explorar la data antes de llegar a EDW.
• Existe varios proyectos relacionados a Hadoop para diferentes tareas, cuales son open sources o propietarios tal como IBM BigInsights / Hortonworks HDP
• Genera un Time-to-Value menor

EDW = Enterprise Data Warehouse
ETL = Extract, Transform and Load)

Production Deployment

Conejito de la Responsabilidad