Category Archives: Uncategorized

Log4j2 configuration example

Here is a simple log4j2 configuration file with a custom logging level for select few packages

  1. Create a file log4j2.xml at src/main/resources directory
  1. <?xml version="1.0" encoding="UTF-8"?><Configuration status="WARN">  <Appenders>    <Console name="Console" target="SYSTEM_OUT">      <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>    </Console>  </Appenders>  <Loggers>    <Logger name="com.foo.Bar" level="trace">      <AppenderRef ref="Console"/>    </Logger>    <Root level="error">      <AppenderRef ref="Console"/>    </Root>  </Loggers></Configuration>

Howto marshal an instance of protobuf to JSON

Proto

syntax = "proto3";

package myproto;

message MyMessage {
    string name = 1;
    int32 age = 2;
}


package main

import (
    "fmt"
    "github.com/golang/protobuf/jsonpb"
    "github.com/golang/protobuf/proto"
    "myproto" // Import the generated protobuf package
)

func main() {
    // Create an instance of MyMessage
    myMessage := &myproto.MyMessage{
        Name: "Alice",
        Age:  30,
    }

    // Create a JSON marshaler
    marshaller := &jsonpb.Marshaler{}

    // Marshal the protobuf message to JSON
    jsonString, err := marshaller.MarshalToString(myMessage)
    if err != nil {
        fmt.Println("Error marshaling to JSON:", err)
        return
    }

    // Print the JSON string
    fmt.Println(jsonString)
}

How to unmarshal protobuf to json in golang

package main

import (
	"encoding/json"
	"fmt"
)

// Define a struct
type SomeStruct struct {
	ID    int    `json:"id"`
	Title string `json:"title"`
}

func main() {
	jsonString := `{
        "id": 1,
        "title": "Some title"
    }`

	var item SomeStruct

	// Unmarshal the JSON data into the struct
	if err := json.Unmarshal([]byte(jsonString), &item); err != nil {
		fmt.Println("Error unmarshaling content:", err)
		return
	}

	fmt.Println("ID:", item.ID)
	fmt.Println("Title:", item.Title)
}

Multiprocessing jobs with worker pool in Python

#multiprocessing jobs with worker pool in python

from multiprocessing import Process, Lock, Pool
import time
import datetime
import sys
import os
from subprocess import Popen, PIPE

def proc(metric):
    print "Working on %s"%(metric)
    cmd1 = "/usr/bin/tsdb scan --import 2012/04/10 sum %s"%(metric)
    cmd2 = "grep %s"%(metric)

    logfile = open("%s.dat.gz"%(metric), 'w')
    p1 = Popen(cmd1.split(" "), stdout=PIPE)
    p2 = Popen(cmd2.split(" "), stdin=p1.stdout, stdout=PIPE)
    p3 = Popen(['gzip'], stdin=p2.stdout, stdout=logfile)
    p3.communicate()
    logfile.close()

if __name__ == '__main__':
    f = open('file_list_of_metrics.txt', 'r')
    l = [i.rstrip() for i in f]
    pool = Pool(processes=10)
    pool.map(proc, l, 1)
    pool.close()
    pool.join()

Loop through dictionary/map/array

#PHP
foreach($map as $k => $v){
echo “key: {$k}, value:{$v}”;
}

#objective-c
for(id key in myDict){
NSLog(@”key:%@, value:%@”, key, [myDict objectForKey:key]);
}

#python
for key in myDict.iterkeys():
print (“key:{0}, value:{0}”.format(key, myDict[key])

#java
for (String key : map.keySet()) {
System.out.println(“key: ” + key + “, value:” + map.get(key));
}