Preface
 
    Sometimes we need to know the details of a program(porcess) when it is running even it's on the edge of crach.There's a lot of tools can be used to do these kind of job such as truss,strace,ltrace,pstack,gstack,gdb,etc.Truss and strace is focus on system call and signal generation whereas pstack,gstack,gdb are relevant with function call.Actually,pstack is a soft link of gstack,and gstack is a shell packaging script of gdb.
 
Introduce
 
    pt-pmp is also relies on linux gdb.It's a tool which aggregate gdb statck traces for a specified program especially for MySQL.pt-pmp can create and summarize full stack traces of linux process by which we can diagnose what the process is waiting for.It is mostly used in performance tuning scenarios.
 
Procedure
 
Usage
 pt-pmp [OPTIONS] [FILES]
Parameters(few parameters in this tool)
 --binary //Specify which binary program to trace(default 'mysqld').

 --pid //Specify a process id to trace.

 --iterations //Specify trace times(default "1").

 --interval //Number of seconds every time(default "0").

 --lines //Specify the number of functions to trace(default "0" means infinite).

 --save-samples //output aggregation into a file for later analysis.
Exapmle
 
Trace gdb stack of mysqld into a file(start mysqld and then execute pt-pmp).
 [root@zlm1 :: ~]

 #pt-pmp --save-samples pmp.log

 Sun Jul   :: CEST

 /usr/bin/pt-pmp: line : gdb: command not found //gdb package is not installed.

 [root@zlm1 :: ~]

 #yum install gdb //Install gdb package first.

 //Omitted

 Installed:

   gdb.x86_64 :7.6.-.el7                                                                                                                         

 Complete!

 [root@zlm1 :: ~]

 #pt-pmp --save-samples pmp.log

 Sun Jul   :: CEST

       __io_getevents_0_4(libaio.so.),LinuxAIOHandler::collect(os0file.cc:),LinuxAIOHandler::poll(os0file.cc:),os_aio_linux_handler(os0file.cc:),os_aio_handler(os0file.cc:),fil_aio_wait(fil0fil.cc:),io_handler_thread(srv0start.cc:),start_thread(libpthread.so.),clone(libc.so.)

        pthread_cond_wait,wait(os0event.cc:),os_event::wait_low(os0event.cc:),srv_worker_thread(srv0srv.cc:),start_thread(libpthread.so.),clone(libc.so.)

        sigwait(libpthread.so.),signal_hand(mysqld.cc:),pfs_spawn_thread(pfs.cc:),start_thread(libpthread.so.),clone(libc.so.)

        sigwaitinfo(libc.so.),timer_notify_thread_func(posix_timers.c:),pfs_spawn_thread(pfs.cc:),start_thread(libpthread.so.),clone(libc.so.)

        pthread_cond_wait,wait(os0event.cc:),os_event::wait_low(os0event.cc:),srv_purge_coordinator_suspend(srv0srv.cc:),srv_purge_coordinator_thread(srv0srv.cc:),start_thread(libpthread.so.),clone(libc.so.)

        pthread_cond_wait,wait(os0event.cc:),os_event::wait_low(os0event.cc:),buf_resize_thread(buf0buf.cc:),start_thread(libpthread.so.),clone(libc.so.)

        pthread_cond_wait,wait(os0event.cc:),os_event::wait_low(os0event.cc:),buf_dump_thread(buf0dump.cc:),start_thread(libpthread.so.),clone(libc.so.)

        pthread_cond_wait,native_cond_wait(thr_cond.h:),my_cond_wait(thr_cond.h:),inline_mysql_cond_wait(thr_cond.h:),compress_gtid_table(thr_cond.h:),pfs_spawn_thread(pfs.cc:),start_thread(libpthread.so.),clone(libc.so.)

        pthread_cond_timedwait,os_event::timed_wait(os0event.cc:),os_event::wait_time_low(os0event.cc:),srv_monitor_thread(srv0srv.cc:),start_thread(libpthread.so.),clone(libc.so.)

        pthread_cond_timedwait,os_event::timed_wait(os0event.cc:),os_event::wait_time_low(os0event.cc:),srv_error_monitor_thread(srv0srv.cc:),start_thread(libpthread.so.),clone(libc.so.)

        pthread_cond_timedwait,os_event::timed_wait(os0event.cc:),os_event::wait_time_low(os0event.cc:),pc_sleep_if_needed(buf0flu.cc:),buf_flush_page_cleaner_coordinator(buf0flu.cc:),start_thread(libpthread.so.),clone(libc.so.)

        pthread_cond_timedwait,os_event::timed_wait(os0event.cc:),os_event::wait_time_low(os0event.cc:),lock_wait_timeout_thread(lock0wait.cc:),start_thread(libpthread.so.),clone(libc.so.)

        pthread_cond_timedwait,os_event::timed_wait(os0event.cc:),os_event::wait_time_low(os0event.cc:),ib_wqueue_timedwait(ut0wqueue.cc:),fts_optimize_thread(fts0opt.cc:),start_thread(libpthread.so.),clone(libc.so.)

        pthread_cond_timedwait,os_event::timed_wait(os0event.cc:),os_event::wait_time_low(os0event.cc:),dict_stats_thread(dict0stats_bg.cc:),start_thread(libpthread.so.),clone(libc.so.)

        poll(libc.so.),vio_io_wait(viosocket.c:),vio_socket_io_wait(viosocket.c:),vio_read(viosocket.c:),net_read_raw_loop(net_serv.cc:),net_read_packet_header(net_serv.cc:),net_read_packet(net_serv.cc:),my_net_read(net_serv.cc:),Protocol_classic::read_packet(protocol_classic.cc:),Protocol_classic::get_command(protocol_classic.cc:),do_command(sql_parse.cc:),handle_connection(connection_handler_per_thread.cc:),pfs_spawn_thread(pfs.cc:),start_thread(libpthread.so.),clone(libc.so.)

        poll(libc.so.),Mysqld_socket_listener::listen_for_connection_event(socket_connection.cc:),connection_event_loop(connection_acceptor.h:),mysqld_main(connection_acceptor.h:),__libc_start_main(libc.so.),_start

        nanosleep(libpthread.so.),os_thread_sleep(os0thread.cc:),srv_master_sleep(srv0srv.cc:),srv_master_thread(srv0srv.cc:),start_thread(libpthread.so.),clone(libc.so.)

 //Above is the messages outupted on screen.All the contents is different functions relevant with linux and mysqld.

 //The output sorts with rules of most-frequen first.

 //The combination of function stacks lead by "__io_getevents_0_4(libaio.so.1)"(which is relevant with io) appears 10 times.
Check the content of output file.
#more pmp.log

TS 845703637.1530408066 -- ::

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ]

[New LWP ] //We got 28 new LWP from 3822 to 3981.

[Thread debugging using libthread_db enabled]

Using host libthread_db library "/lib64/libthread_db.so.1".

0x00007f50efe74b7d in poll () from /lib64/libc.so.

Thread  (Thread 0x7f50e7ec1700 (LWP )): //It's the last thread in pmp.log file here.

#  0x00007f50efdbf7da in sigwaitinfo () from /lib64/libc.so.

#  0x0000000000f5171b in timer_notify_thread_func (arg=<optimized out>) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./mysys/posix_timers.c:

#  0x0000000000f707b4 in pfs_spawn_thread (arg=0x30cb000) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/perfschema/pfs.cc:

#  0x00007f50f13c1df5 in start_thread () from /lib64/libpthread.so.

#  0x00007f50efe7f1ad in clone () from /lib64/libc.so.

Thread  (Thread 0x7f50ded07700 (LWP )):

#  0x00007f50f11b8644 in __io_getevents_0_4 () from /lib64/libaio.so.

#  0x000000000106a514 in LinuxAIOHandler::collect (this=0x7f50ded06e10) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/innobase/os/os0file.cc:

#  0x000000000106bc34 in LinuxAIOHandler::poll (this=0x7f50ded06e10, m1=0x7f50ded06ec8, m2=0x7f50ded06ec0, request=0x7f50ded06e90) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/innobase/os/os0file.cc:

#  0x000000000106d65c in os_aio_linux_handler (request=0x7f50ded06e90, m2=0x7f50ded06ec0, m1=0x7f50ded06ec8, global_segment=) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/innobase/os/os0file.cc:

#  os_aio_handler (segment=, m1=0x7f50ded06ec8, m2=0x7f50ded06ec0, request=0x7f50ded06e90) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/innobase/os/os0file.cc:

#  0x000000000120196d in fil_aio_wait (segment=) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/innobase/fil/fil0fil.cc:

#  0x000000000110e980 in io_handler_thread (arg=<optimized out>) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/innobase/srv/srv0start.cc:

#  0x00007f50f13c1df5 in start_thread () from /lib64/libpthread.so.

#  0x00007f50efe7f1ad in clone () from /lib64/libc.so.

Thread  (Thread 0x7f50de506700 (LWP )):

#  0x00007f50f11b8644 in __io_getevents_0_4 () from /lib64/libaio.so.

#  0x000000000106a514 in LinuxAIOHandler::collect (this=0x7f50de505e10) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/innobase/os/os0file.cc:

#  0x000000000106bc34 in LinuxAIOHandler::poll (this=0x7f50de505e10, m1=0x7f50de505ec8, m2=0x7f50de505ec0, request=0x7f50de505e90) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/innobase/os/os0file.cc:

#  0x000000000106d65c in os_aio_linux_handler (request=0x7f50de505e90, m2=0x7f50de505ec0, m1=0x7f50de505ec8, global_segment=) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/innobase/os/os0file.cc:

#  os_aio_handler (segment=, m1=0x7f50de505ec8, m2=0x7f50de505ec0, request=0x7f50de505e90) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/innobase/os/os0file.cc:

#  0x000000000120196d in fil_aio_wait (segment=) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/innobase/fil/fil0fil.cc:

#  0x000000000110e980 in io_handler_thread (arg=<optimized out>) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/innobase/srv/srv0start.cc:

#  0x00007f50f13c1df5 in start_thread () from /lib64/libpthread.so.

#  0x00007f50efe7f1ad in clone () from /lib64/libc.so.

//Omitted.

Thread  (Thread 0x7f50deeb2700 (LWP )):

#  0x00007f50f13c8ec1 in sigwait () from /lib64/libpthread.so.

#  0x00000000007c357b in signal_hand (arg=<optimized out>) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./sql/mysqld.cc:

#  0x0000000000f707b4 in pfs_spawn_thread (arg=0x386a740) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/perfschema/pfs.cc:

#  0x00007f50f13c1df5 in start_thread () from /lib64/libpthread.so.

#  0x00007f50efe7f1ad in clone () from /lib64/libc.so.

Thread  (Thread 0x7f50be7fc700 (LWP )):

#  0x00007f50f13c5705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.

#  0x0000000000ebe6f5 in native_cond_wait (mutex=<optimized out>, cond=<optimized out>) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./include/thr_cond.h:

#  my_cond_wait (mp=<optimized out>, cond=<optimized out>) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./include/thr_cond.h:

#  inline_mysql_cond_wait (src_line=, src_file=0x15d92e0 "/export/home/pb2/build/sb_0-26514852-1514433850.9/mysql-5.7.21/sql/rpl_gtid_persist.cc", mutex=<optimized out>, that=<optimized out>) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./include/mysql/psi/mysql_thread.h:

#  compress_gtid_table (p_thd=<optimized out>) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./sql/rpl_gtid_persist.cc:

#  0x0000000000f707b4 in pfs_spawn_thread (arg=0x386a740) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/perfschema/pfs.cc:

#  0x00007f50f13c1df5 in start_thread () from /lib64/libpthread.so.

#  0x00007f50efe7f1ad in clone () from /lib64/libc.so.

Thread  (Thread 0x7f50dee81700 (LWP )):

#  0x00007f50efe74b7d in poll () from /lib64/libc.so.

#  0x00000000012bae8f in vio_io_wait (vio=<optimized out>, event=<optimized out>, timeout=) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./vio/viosocket.c:

#  0x00000000012baf83 in vio_socket_io_wait (vio=<optimized out>, event=<optimized out>) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./vio/viosocket.c:

#  0x00000000012bb5b8 in vio_read (vio=0x7f50b0000bb0, buf=0x7f50b000a3c0 "\001", size=) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./vio/viosocket.c:

#  0x0000000000c6de03 in net_read_raw_loop (net=0x7f50b0002570, count=) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./sql/net_serv.cc:

#  0x0000000000c6e69b in net_read_packet_header (net=0x7f50b0002570) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./sql/net_serv.cc:

#  net_read_packet (net=0x7f50b0002570, complen=0x7f50dee80d38) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./sql/net_serv.cc:

#  0x0000000000c6e94c in my_net_read (net=0x7f50b0002570) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./sql/net_serv.cc:

#  0x0000000000c7c1dc in Protocol_classic::read_packet (this=0x7f50b0001e18) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./sql/protocol_classic.cc:

#  0x0000000000c7af52 in Protocol_classic::get_command (this=0x7f50b0001e18, com_data=0x7f50dee80de0, cmd=0x7f50dee80e0c) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./sql/protocol_classic.cc:

# 0x0000000000d1cf47 in do_command (thd=0x7f50b0000dc0) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./sql/sql_parse.cc:

# 0x0000000000ded7ac in handle_connection (arg=<optimized out>) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./sql/conn_handler/connection_handler_per_thread.cc:

# 0x0000000000f707b4 in pfs_spawn_thread (arg=0x382fa60) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./storage/perfschema/pfs.cc:

# 0x00007f50f13c1df5 in start_thread () from /lib64/libpthread.so.

# 0x00007f50efe7f1ad in clone () from /lib64/libc.so.

Thread  (Thread 0x7f50f17e8740 (LWP )):

#  0x00007f50efe74b7d in poll () from /lib64/libc.so.

#  0x0000000000deeaf9 in Mysqld_socket_listener::listen_for_connection_event (this=0x30d96f0) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./sql/conn_handler/socket_connection.cc:

#  0x00000000007c89c4 in connection_event_loop (this=0x373e050) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./sql/conn_handler/connection_acceptor.h:

#  mysqld_main (argc=, argv=0x2f897b8) at /export/home/pb2/build/sb_0--1514433850.9/mysql-5.7./sql/mysqld.cc:

#  0x00007f50efdaaaf5 in __libc_start_main () from /lib64/libc.so.

#  0x00000000007be479 in _start ()

TS 788084395.1530408210 -- ::

[root@zlm1 :: ~]

#
Demonstrate of relevant conceptions.
 .What's gdb?

 gdb is tool of linux,a debugger of GNU project.It can help you to see what's going on inside the program while it executes.For example,the usual case is the program running slowly or almost to be crashed.

 .What can gdb do?

 It can catch details in the act belowl:

 ).Start the program and specify anything the might affect its behavior.

 ).Let the program stop on specific conditions.

 ).Check the details when the program stops.

 ).Change things in the program and try to correct effect of potential problems.

 .What's LWP?

 LWP is abbreviation of Light Weight Process.

 Process:You'll find a process in background after you've executed a linux command(which can be observed by "ps -ef").

 Thread:It's nothing but a flow of execution of the linux process.

 Light Weight Process:It's almost the same with "thread" but a term at kernal level.

 Here's some detail of it:

 What are Linux Processes, Threads, Light Weight Processes, and Process State

 https://www.thegeekstuff.com/2013/11/linux-process-and-threads/
Something about output file.
 .The second column in the file shows the detail of memory address with hex.

 .At the very beginning of the file in Thread (LWP ),it shows the detail of how MySQL process works.

 "Mysqld_socket_listener::listen_for_connection_event" is a MySQL function defined in source code file "socket_connection.cc".This is a clue which can help you to findout where to servay the details if something happened and stucked here.

 .At every bottom of each thread(except thread ),you can see the same contents below:

 "#. 0x... clone () from /lib64/libc.so.6" //clone() is a function to create a new thread.

 "#. 0x... start_thread () from /lib64/libpthread.so.0" //start_thread() is a function to start a poxis thread.
Summary
  • pt-pmp is read-only tool and it depends on the linux gdb to collect stack traces.
  • when pt-pmp works,it will attach gdb to the program you specified,what will probably freeze the program for a while.
  • It's not recommend to run the tool on a very busy product system because of the potential freezing period and resource consumption.
  • As a matter of fact,you can also do the stack tracing stuff by pstack tool but that's not today's motif.
 

Percona-Tookit工具包之pt-pmp的更多相关文章

  1. Linux后台开发工具箱

    https://files-cdn.cnblogs.com/files/aquester/Linux后台开发工具箱.pdf 目录 目录 1 1. 前言 3 2. 脚本类工具 3 2.1. sed命令- ...

  2. Mysql: pt-table-checksum 和 pt-table-sync 检查主从一致性，实验过程

    一.安装 percona 包 1.安装仓库的包 https://www.percona.com/doc/percona-repo-config/yum-repo.html sudo yum insta ...

  3. Linux后台开发工具箱-葵花宝典

    Linux后台开发工具箱-葵花宝典 一见 2016/11/4 目录 目录 1 1. 前言 4 2. 脚本类工具 4 2.1. 双引号和单引号 4 2.2. 取脚本完整文件路径 5 2.3. 环境变量和 ...

  4. 推荐几款MySQL相关工具

    前言: 随着互联网技术的不断发展, MySQL 相关生态也越来越完善,越来越多的工具涌现出来.一些公司或个人纷纷开源出一些不错的工具,本篇文章主要介绍几款 MySQL 相关实用工具.提醒下,这里并不介 ...

  5. [知识库分享系列] 二、.NET（ASP.NET）

    最近时间又有了新的想法,当我用新的眼光在整理一些很老的知识库时,发现很多东西都已经过时,或者是很基础很零碎的知识点.如果分享出去大家不看倒好,更担心的是会误人子弟,但为了保证此系列的完整,还是选择分享 ...

  6. SQL慢查询安装过程

    SQL慢查询 基本操作 打开防火墙 firewall-cmd --zone=public --add-port=3306/tcp --permanent firewall-cmd --reload 安 ...

  7. 快速安装Percona pt工具

    yum install perl-DBI perl-DBD-MySQL perl-Time-HiRes perl-Time-HiRes perl-IO-Socket-SSLwget http://pk ...

  8. Percona 工具包 pt-online-schema-change 简介

    mysql的在线表结构修改,因为低效和阻塞读写.一直被诟病.至于ALTER TABLE 的原理,参看我上一篇文章.MySQL在线修改大表结构.看完后,发现的问题是还是会锁的,且对于在线更新的这块也是不 ...

  9. 安装percona工具包

    1.安装percona源 sudo yum install http://www.percona.com/downloads/percona-release/redhat/0.1-4/percona- ...

  10. percona pt toolkit 总结

    ##=====================================================##pt-osc之工作流程:1.检查更改表是否有主键或唯一索引,是否有触发器2.检查修改表 ...

随机推荐

  1. ubuntu14.04通过 gvm 安装 go语言开发环境

    最近用回了ubuntu ,所以打算安装golang学习当下比较火热的这个语言 本来打算使用 sudo apt-get install golang的 安装后发现 是1．2．1不是最新版 所以上网上搜了 ...

  2. Video 视频播放防作弊和禁止下载

    1.实现效果 - 查看源码 实现视频可播放不能下载,禁止右键下载.F12源码打开链接下载 实现只在当前窗口播放,切换窗口.窗口最小化.窗口被遮挡停止播放,恢复后继续播放 在线demo:缓存完再播放 . ...

  3. js动态控制导航栏样式

    导航栏一般做为母版页,为了使增加用户体验,往往在用户进入某个页面给予导航栏相应的样式,这里可以用js动态添加 <div class="box_left fl"> < ...

  4. winform文件拖入

    //view.AllowDrop = true; ---------------------------------------- private void view_DragEnter(DragEv ...

  5. 反向代理总结-reverse-proxy-with-url-rewrite

    iis 反向代理 : 1. 微软文档 https://docs.microsoft.com/en-us/iis/extensions/url-rewrite-module/reverse-proxy- ...

  6. nopcommerce 3.6网银在线支付插件（源码）

    网银在线支付插件,下载后通过后台插件管理安装.配置即可使用. 下载:网银在线支付插件3.1.3.6版.rar (106.3KB) 源代码放在\Plugins目录下,用vs打开重新生成. 源地址:htt ...

  7. AJAX跨域POST发送json时，会先发送一个OPTIONS预请求

    我们会发现,在很多post,put,delete等请求之前,会有一次options请求. 根本原因就是,W3C规范这样要求了!在跨域请求中,分为简单请求(get和部分post,post时content ...

  8. JSON 与 XML基本了解

    简单了解JSON 和 XML ,以及他们的区别: JSON:是一种轻量级的数据交换格式,ECMA(欧洲计算机制造商协会)的一个子集:   优点:轻量级.占用宽带小.易于人的阅读和编写,便于js解析,支 ...

  9. Azure 进阶攻略 | 上云后的系统，「门禁」制度又该如何实现？

    各位办公室白领们,不妨回想一下自己每天去公司上班时的一些细节. 为避免「闲杂人等」进入工作场所,我们需要证明自己是这家公司的员工才能进入,对吧!所有员工,无论所属部门或职位,都必须先证明自己身份,例如 ...

  10. python标准库 － socket

    地址簇(address family) socket.AF_UNIX # (UNIX Domain Sockets) socket.AF_INET # ipv4 socket.AF_INET6 # i ...