Author Archives: KsI - Page 2

video sound track merger

Few “years” ago I made part of small promo project for Nestle Russia as subcontractor.
It was promo action, website with some videos. Kids make sound track and my task was to merge user sound track and original video soundtrack.
It`s really easy to do with ffmpeg or mencoder.

BTW: ffmeg much better it works o.k. with aac codec and mp4 container.

Code is VERY VERY dirty, we had absolutely no time, but it can be useful to someone. And I save it “just to remember”.

#!/bin/bash

( #start subprocess
  # Wait for lock on /var/lock/.merger-1.lock (fd 200) for 10 seconds
  flock -x -w 3 200
  if [ "$?" != "0" ]; then echo Cannot lock!; exit 1; fi
  echo $$>>/var/lock/.merger-1.lock #for backward lockdir compatibility, notice this command is executed AFTER command bottom  ) 200>/var/lock/.myscript-1.exclusivelock.


sourcevideo="/var/www/kinder_prod/sourcevideo"
sourceaudio="/var/www/kinder_prod/audioupload"
targetdir="/var/www/kinder_prod/processedvideo"
processedaudio="/var/www/kinder_prod/processedaudio"

while true; do

if [ "$(ls -A $sourceaudio)" ]; then

  for i in `ls -1 $sourceaudio/*.wav | xargs -n1 basename`; do
  videoid=`echo $i | awk -F"--" '{print $1}'`
  audioid=`echo $i | awk -F"--" '{print $2}' | awk -F"." '{print $1}'`

  sox $sourceaudio/$i /tmp1/$i rate 44100; mv /tmp1/$i $sourceaudio/$i; chown milkslice:milkslice $sourceaudio/$i || exit 1

  sox -m $sourcevideo/$videoid.mp3 $sourceaudio/$i /tmp1/$videoid--$audioid.mp3 && \
  ffmpeg -y -i /tmp1/$videoid--$audioid.mp3 -strict experimental -acodec aac -bsf:a aac_adtstoasc /tmp1/$videoid--$audioid.aac && \
    ffmpeg -y -i /tmp1/$videoid--$audioid.aac -i $sourcevideo/$videoid.mp4 -bsf:a aac_adtstoasc -preset ultrafast -c copy $targetdir/$videoid--$audioid.mp4 || exit 1
#   mencoder -of lavf -lavfopts format=mp4 -oac copy  -fafmttag 0x706D  \
#-audiofile /tmp1/$videoid--$audioid.aac  -ovc copy $sourcevideo/$videoid.mp4 -o $targetdir/$videoid--$audioid.mp4 || exit 1
    chown milkslice:milkslice $targetdir/$videoid--$audioid.mp4
    mv -f $sourceaudio/$i $processedaudio
    rm /tmp1/$videoid--$audioid.mp3
        rm /tmp1/$videoid--$audioid.aac

    done

fi

sleep 1;
done

) 200>/var/lock/.merger-1.lock   #exit subprocess

FLOCKEXIT=$?  #save exitcode status

exit $FLOCKEXIT

And run screen with script. (alternative to upstart)

/usr/bin/screen -dm bash -c 'cd /root/merger-prod; /root/merger-prod/merger-prod.sh'

How to build dpkg from pecl

We need new mongo driver.
pecl install lastest
is not good solution, leads to chaos in system.

get the desired mongo extension tgz
http://pecl.php.net/package/mongo

aptitude install  dh-make-php php5-dev build-essential debhelper

wget http://pecl.php.net/get/mongo-1.6.11.tgz
OR pecl download mongo
dh-make-pecl --phpversion 5 --prefix php5- mongo-1.6.11.tgz
./debian/rules binary

Great Thanks to author: https://www.dotdeb.org/2008/09/25/how-to-package-php-extensions-by-yourself/
He saved my day.

How to delete files without big iowait

I know 2 ways, tested in high loaded production.

if scheduler support ionice (on some systems makes LA)

 # ionice -c 3 nice -n 20 find  /DIRECTORY -type f -delete

Just ajust sleep time, according to your system LA

while true; do find /DIRECTORY/ -type f -print  -delete -quit; sleep 0.01; done

mysql 5.6 GTID global transaction identifier

Wow! It`s a really nice feature. Now you can do very easy replication.
i.e. In pre 5.6 you should create replica like this:

1. Turn on binary logs at master

 vi /etc/mysql/my.cnf
 server-id              = 11
 log_bin                 = /var/log/mysql/mysql-bin.log
 # WARNING: Using expire_logs_days without bin_log crashes the server! See README.Debian!
 expire_logs_days        = 10
 max_binlog_size         = 100M
 binlog_do_db            = mydatabase
 #binlog_ignore_db       = include_database_name
 binlog-format=ROW     #I MIXED and STATEMENT sometimes not good
binlog-checksum=crc32  # 5.6 feature speed up binlog
gtid-mode=on           #Use force, Luke

2. Create replication User

 grant replication slave on *.* to 'repl_user'@'%' identified by 'SecurePassword';

3. Dump all databases

mysqldump --master-data=2 --single-transaction --events --routines --triggers --all-databases  > database.sql

4. On slave after dump restore

 CHANGE MASTER TO MASTER_HOST='masterHost', MASTER_USER='repl_user',MASTER_LOG_FILE=, MASTER_LOG_POS=,
 MASTER_PASSWORD='SecurePassword';
 START SLAVE;
 show slave status;

But at 5.6 On slave

change master to MASTER_HOST='masterHost", MASTER_AUTO_POSITION=1, MASTER_USER=’repl_user’, MASTER_PASSWORD=’SecurePassword';
START SLAVE;
show slave status;

P.S. If you need to skip one request on slave:

SET GLOBAL SQL_SLAVE_SKIP_COUNTER=1; START SLAVE;

nginx proxy_pass and cache regexp location.

nginx cannot proxy_pass at regexp location. I made this workaround.
Works great! Now I can cache any static data provided by backend. 🙂 from any location!

location ~* \.(gif|jpg|png|ico)$ {
      rewrite ^.(gif|jpg|png|ico) /$1 break;
      proxy_pass         http://127.0.0.1:8080;
      proxy_redirect     off;
      proxy_set_header    Host             $host;
      proxy_set_header    X-Real-IP        $remote_addr;

      proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
      client_max_body_size       150m;
      client_body_buffer_size    128k;
      proxy_connect_timeout      90;
      proxy_send_timeout         90;
      proxy_read_timeout         90;
      proxy_buffer_size          4k;
      proxy_buffers              4 32k;
      proxy_busy_buffers_size    64k;
      proxy_temp_file_write_size 64k;

      proxy_cache cache_common;
      proxy_cache_key "$host|$request_uri";
      proxy_cache_valid 200 302 301 15m;
      proxy_cache_valid 404         10s;
      proxy_cache_valid any          1m;
        }

kill process running longer than (bash)….

At one our advertising server located far beyond in another galaxy 🙂 🙂 rsync over ssh begin to hung sometimes without any reason.
of course, we will try strace and other debug tools but tomorrow. Today we need quick fix sollution.

BTW
removing compression not help, and –timeout option rather not help solve this case
my rsync command:

 rsync --timeout=30 -apvre ssh -o StrictHostKeyChecking=no
       --remove-source-files /opt/logrsync/workdir/clicks/etl/20150707215235-SERVERNAME.pb.gz
       etl@etl2-1.SERVERNAME.it.randomthemes.com:~/etl/data/sources/clicks/

How to find rsync processes running more then 10 seconds, and kill them (bash):

while true; do
      for i in `ps -C rsync -o pid=,etimes= | awk '{if ($2 > 10) print $1}'`; do
       echo $i; kill $i; sleep 10;
      done
done

if somebody solve the same rsync issue – please, please tell me how!

In our case everything start working o.k. without any action, It was connectivity issue, but very very strange.
–timeout should help.

bash options string example

Just to remember.

#!/bin/bash

usage() { echo "Usage: $0 [-s <45|90>] [-p <string>]" 1>&2; exit 1; }

while getopts ":s:p:" o; do
    case "${o}" in
        s)
            s=${OPTARG}
            ((s == 45 || s == 90)) || usage
            ;;
        p)
            p=${OPTARG}
            ;;
        *)
            usage
            ;;
    esac
done
shift $((OPTIND-1))

if [ -z "${s}" ] || [ -z "${p}" ]; then
    usage
fi

echo "s = ${s}"
echo "p = ${p}"

dns requests statistics

Today I made huge investigation, why our DNS servers serve huge ammount of traffic 5Mb\s per server. (we have only 200000000 advertising requests).
Googling gives me ultimate utility!

dnstop

In ubuntu just

aptitude update; aptitude install dnstop

dnstop works via libpcap, so no matter what DNS Server you use. (bind, dnsmasq or powerdns).
I found, that some our mail relays were misconfigured and use master DNS servers instead of local bind cachers\resolvers. And solve huge DNS traffic issue.

So one more useful utility in addition to top,htop,iftop,mytop.
🙂

Is heaper threading enabled linux?

How to check is heaper threading enabled at your server.

use /proc/cpuinfo
Some OPS recommend to check HT cpu flag, but according to manuals HT – for some processors mean HyperTransport for others mean Heaper Threading

Better way to count siblings

The kernel data Linux exposes in /proc/cpuinfo will show each logical cpu with a unique processor number. A logical cpu can be a hyperthreading sibling, a shared core in a dual or quad core, or a separate physical cpu. We must look at the siblings, cpu cores and core id to tell the difference.

If the number of cores = the number of siblings for a given physical processor, then hyperthreading is OFF.

cat /proc/cpuinfo | grep siblings | wc -l; cat /proc/cpuinfo | grep cores | wc -l

iptables SNAT vs MASQUERADE

What is a difference and why should we use SNAT instead of MASQUERADE.

According to official documentation:

There is a specialized case of Source NAT called masquerading: it should only be used for dynamically-assigned IP addresses, such as standard dialups (for static IP addresses, use SNAT above).

With SNAT, the kernel’s connection tracking keeps track of all the connections when the interface is taken down and brought back up. For the MASQUERADE target connection will be lost.

With MASQUERADE some issues can occur if your have more than one ip on outgoing interface.

With MASQUERADE kernel determine nat outgoing ip address for every connection (it looks for interface IP) it`s rather expensive operation.

But in 99.99% cases MASQUERADE is o.k.

I Use following iptables construction to nat rear outgoing SMTP connections. (postfix started at physical server, and lxc containers relay mail to base system via ssmtp or nullmailer).

/sbin/iptables -t nat -A POSTROUTING -s 10.2.1.254/32  -o eth0 -j MASQUERADE

It`s universal chain, works great at number of servers, and you should not determine outgoing interface address. (as for -j SNAT –to-source X.X.X.X)