How to reset timezone in Linux/Centos server:

There are two way to do this:

1) cp /usr/share/zoneinfo/Singapore /etc/localtime
*2) ln -s /usr/share/zoneinfo/Singapore /etc/localtime

* For creating soft link, please make sure localtime file should not be exist in /etc path folder. You can remove or rename localtime file first

Update Confluence (wiki) page by node.js

Getting started.....

# mkdir  -p /usr/local/wiki_update_folder
Install confluence-api via npm:
# npm install confluence-api

# vi update_wiki_page_git_version.js

var child = require('child_process')
var Confluence = require("confluence-api");
var config = {
    username: "test-user",    // your confluence userid
    password: "test-pass",      // your confluence password
    baseUrl:  "https://<your_wiki_url>/wiki"
};

var confluence = new Confluence(config);
confluence.getContentByPageTitle("SPACE_NAME", "PAGE_TITLE", function(err, data) {
    ver_no = data.results[0].version.number;
    ver_no=ver_no+1 ;
    child.exec("date",function(err,stdout,stderr){
        confluence.putContent("SPACE_NAME","PAGE_ID",ver_no, "PAGE_TITLE",stdout,function(err, data) {});
    });
}); 


e.g:
If you want to display your script output in wiki. 
It can be very useful in case you want to publish any status into confluence. Also it can be automated by cron or any task scheduler commands. 

var child = require('child_process')
var Confluence = require("confluence-api");
var config = {
    username: "testuser",
    password: "testpass",
    baseUrl:  "https://wiki-confluence-url/wiki"
};

var confluence = new Confluence(config);
confluence.getContentByPageTitle("WIKI_SPACE_NAME", "PAGE_TITLE", function(err, data) {
    ver_no = data.results[0].version.number;
    ver_no=ver_no+1 ;
    shell_comm="sh test.sh'";
    child.exec(shell_comm,function(err,stdout,stderr){
        confluence.putContent("WIKI_SPACE_NAME","WIKI_PAGE_ID",ver_no, "PAGE_TITLE","<pre>"+stdout+"</pre>",function(err, data) {});
    });
});

Read Recent Logs only

Hi All,

Sometimes, we have a situation to read recent logs from the log file which continuously growing from the current logs; source can be anything like system logs, application logs, database logs, device logs etc etc...

My Problem- Need to read all recent slow queries of mongo (nosql database) logs and notified when it breaches threshold (400ms).

Solution- It can be achieved by using various scripting/programming language like node.js or other scripting language, I opt 'BASH script.

#!/bin/bash

## Please update the value according to your system/environment.

## set variable

logfilepath=/var/log/mongo                                          # please change the path as per the environment

name=mongod.log                                                         # mongo log file name

logrecord=<path_to_capture_current_script_log>        # for recording current script log

MaxLLN_file=<file_to_hold_max_LLN_value>         # for maintaing Max Last Line Number

slow_query_log_record=<logged_only_slow_queries>

tmpfile=<temp_file_path>

mailnotification=<notification_filename_which we have to monitored/display/forward>

## Set variable for mail

to='abc@xyz.com'

from='Sender:xxx'

sub='<subject_of_the_mail>'

## No need to change/update anything here. Please change cautiously,if needed.

## If file exists having start line number then save it into a file.

if [ -f $MaxLLN_file ];then

    echo -e "[`date +%F_%T`] $MaxLLN_file File exist, max LLN value is copied" >> $logrecord

    startlineno=`cat $MaxLLN_file`

else

    # If file is not exist

    echo -e "[`date +%F_%T`] $MaxLLN_file doesn't exist so startlineno counter start from 1" >> $logrecord

    startlineno=1

    echo 1 > $MaxLLN_file

fi

while true

do

    startlineno=`cat $MaxLLN_file`

    totallineno=`wc -l $logfilepath/$name|awk '{print $1}'`

    if [ $startlineno -le $totallineno ];then

        echo -e "[`date +%F_%T`] Slow log search start from between $startlineno untill $totallineno line number" >> $logrecord

        slowqeries_count=`sed -n "$startlineno","$totallineno"p $logfilepath/$name | grep -c 'ms'`

        if [ $slowqeries_count -ge 1 ];then

            echo -e "[`date +%F_%T`] $slowqeries_count slow queries found between $startlineno and $totallineno line number" >> $logrecord

            sed -n "$startlineno","$totallineno"p $logfilepath/$name | grep 'ms' > $tmpfile

            `cat $tmpfile >> $slow_query_log_record`

            echo -e "Dear All,\n\nBelow are the Slow query logs of Mongo Server `hostname` ( taking greater than or equal to 400ms)\n\n" > $mailnotification

            cat $tmpfile | while read line

            do

                if [ `echo $line | gawk '{print $NF-400}'` -ge 0 ];then echo $line >> $mailnotification

                fi

            done

            echo -e "\n\n Thanks & Best Regards,\nAnurag Bisht" >> $mailnotification

            echo "Subject: $sub" | cat - $mailnotification | sendmail -F"$from" -t "$to"

            echo > $mailnotification;

        else

            echo -e "[`date +%F_%T`] $slowqeries_count Slow queries found between $startlineno and $totallineno line number" >> $logrecord

        fi

        totallineno=`expr $totallineno + 1`

        echo $totallineno > $MaxLLN_file

        echo -e "[`date +%F_%T`] New search will start from `cat $MaxLLN_file` value" >> $logrecord

        echo -e "---------------------------------" >> $logrecord

    fi

done