Percona-Tookit工具包之pt-ioprofile

 

Preface

 

    As a matter of fact,disk IO is the most important factor which tremendously influence performance of database especially in OLTP which is usually called IO-intensive system.The high concurrency is always in company with high IOPS as well.Furthermore,it's also a bottleneck in many scenarios.Thus,we have to monitor the IO cost of MySQL db by different tools such as zabbix,lepus.They usually provide a entire db performance monitoring not merely IO status.

 

Introduce

 

    pt-ioprofile is a tool of Percona-Toolkit which can be used to monitor the IO activities by MySQL itself.It provide direct and quantitive informations and indicate the real IO costs by different processes or relevent files.pt-ioprofile is the tool which combines lsof and strace to analyze informations.

 

Procedure

 

Usage

 pt-ioprofile [OPTIONS] [FILE]

Main parameter(they're almost entire)

 --aggregate -- Whether use aggregate function or not(default "sum",others "avg").
 --cell -- Specify the type of cell contents(default "times",others "size","count").
 --group-by -- Specify the type of group by contents(default "filename",others "all","pid").
 --profile-process -- Specify the process which is to be profiled(default muysqld).
 --profile-pid -- Specify the pid instead of prcocess name.
 --run-time -- Specify how long time it will take(default 30s).
 --save-samples -- Specify a file which sample data can be put in.

Examples

 

Execute pt-ioprofile to have a test.

 [root@zlm2 :: ~]
 #ps aux|grep mysqld
 mysql       0.0 19.0   pts/  Sl   :   : mysqld --defaults-file=/data/mysql/mysql3306/my.cnf
 root        0.0  0.0     pts/    R+   :   : grep --color=auto mysqld

 [root@zlm2 :: ~]
 #pt-ioprofile --cell size --run-time
 Tue Jun  :: CEST
 Tracing process ID
      total filename -- There's nothing output here,I'm afraid I've encountered a bug.

 ###Here's a website about the bug.###
 https://bugs.launchpad.net/percona-toolkit/+bug/925778

 [root@zlm2 :: ~]
 #pt-ioprofile --version
 pt-ioprofile 3.0. -- My version of Percorna-Toolkit is 3.0..

 [root@zlm2 :: ~]
 #yum list|grep percona-toolkit
 percona-toolkit.x86_64                      3.0.-.el7               installed

Erase the latest Porcona-Toolkit 3.10.0 and change the old version 2.2.20.

 root@zlm2 :: ~]
 #yum erase percona-toolkit

 [root@zlm2 :: ~]
 #wget https://www.percona.com/downloads/percona-toolkit/2.2.20/RPM/percona-toolkit-2.2.20-1.noarch.rpm

 [root@zlm2 :: ~]
 #yum localinstall percona-toolkit-2.2.-.noarch.rpm

 [root@zlm2 :: ~]
 #pt-ioprofile --version
 pt-ioprofile 2.2.

 [root@zlm2 :: ~]
 #time pt-ioprofile --cell size --run-time
 Tue Jun  :: CEST
 Tracing process ID
      total filename -- It still doesn't work properly without a file specified.

 real    0m11.127s
 user    0m0.048s
 sys     0m0.081s

There're percona release notes below which describes the bug is fixed in v2.0.3.

 https://www.percona.com/doc/percona-toolkit/3.0/release_notes.html
 ...
 Fixed bug : pt-ioprofile doesn’t run without a file
 ...

    I'm really confused with why it cannot be executed properly even though in the newest version.No more stuff I can find to solve the problem now.Maybe I'll test it another day.