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Mass Rename of Files

In Linux you can use the rename command to rename files in masses

# rename all coinsurance of 'Post' in the name of all java files in the
# current directory and  its sub-directories to 'Comment'

find -name "*.java" | xargs rename 's/Post/Comment/g'

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Tuning Storm+Trident

Tuning a dataflow system is easy:

The First Rule of Dataflow Tuning:
* Ensure each stage is always ready to accept records, and
* Deliver each processed record promptly to its destination

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Too Many Files Open

On Linux you might encounter an issue with too many files open at the same time during the building of the maven project or running while running the application server: To fix the issue do the following:

1. Edit "/etc/sysctl.conf" as a super user:

sudo gedit /etc/sysctl.conf

1. Make sure the below flag is set to 200000 or higher:

#set to 2^18 = 262144
fs.file-max = 262144

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#Go to directory which contains weblogic.jar ($WL_HOME/server/lib) and run below command

java -cp weblogic.jar weblogic.version

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worker_processes 1;

events {
    worker_connections 1024;
}

http {
    include mime.types;
    default_type application/octet-stream;
    sendfile on;

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server { listen  80;
  server_name example.com;
  access_log /var/log/example.com/nginx.access.log;
  error_log  /var/log/example.com/nginx.error.log;
  root /var/www/apps/example.com/public;
  charset utf-8;

  location / {
    rewrite ^ https://$host$request_uri? permanent;
  }

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- action: ec2_facts

- apt: pkg=lvm2 state=present
- apt: pkg=mdadm state=present

- pip: name=boto state=latest

- ec2_vol: instance="{{ hostvars[inventory_hostname]['ansible_ec2_instance-id'] }}"
           volume_size=20
           device_name="{{ item }}"

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ec2-1-2-3-4.compute-1.amazonaws.com new_hostname=new-hostname.example.com
ec2-5-6-7-8.compute-1.amazonaws.com

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# rename all occurrences of 'Post' in the name of all java files
# in the current directory and its sub-directories to 'Comment'

find -name "*.java" | xargs rename 's/Post/Comment/g'

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gremlin> g = TitanFactory.open("berkeleyje:/tmp/test")
==>titangraph[berkeleyje:/tmp/test]
gremlin> mgmt = g.getManagementSystem();
==>com.thinkaurelius.titan.graphdb.database.management.ManagementSystem@27c04377
gremlin> id = mgmt.makePropertyKey("uid").dataType(Long.class).make()
==>uid
gremlin> mgmt.buildIndex('byUID',Vertex.class).addKey(id).buildCompositeIndex()
==>com.thinkaurelius.titan.graphdb.database.management.TitanGraphIndexWrapper@14f3c6fc
gremlin> mgmt.commit()
gremlin> for (int i=0;i<200;i++) { v = g.addVertex([uid:(int)Math.floor(i/2)])}