标签
PostgreSQL , Linux , pidstat
背景
如果我们要查看Linux下面进程、进程组、线程的资源消耗的统计信息，可以使用pidstat，它可以收集并报告进程的统计信息。
pidstat实际上也是将/proc/pid下的统计信息统筹后展现给用户。
pidstat例子
1. 列出IO统计信息：-d
2. 列出内存使用统计，page fault：-r
3. CPU统计信息：-u
4. 上下文切换统计信息：-w
5. 指定输出的维度
指定命令： -C command
指定进程号：-p { pid [,...] | SELF | ALL }
将所有列输出到单行、便于导入单张表中：-h
按每个CPU核的统计：-I
按所有CPU核统计：默认
列出命令的完整内容，包括参数：-l
列出线程统计信息：-t
按进程维度单独统计、按进程全局+子进程单独统计、按进程全局、单独统计同时按子任务单独统计：-T { TASK | CHILD | ALL }
实例，统计5秒的值并输出
#pidstat -d -r -u -w -l -h -p ALL 5 1|less
# Time PID %usr %system %guest %CPU CPU minflt/s majflt/s VSZ RSS %MEM kB_rd/s kB_wr/s kB_ccwr/s cswch/s nvcswch/s Command
1488541252 1 0.00 0.00 0.00 0.00 0 0.00 0.00 19348 1512 0.00 0.00 0.00 0.00 0.00 0.00 /sbin/init
1488541252 2 0.00 0.00 0.00 0.00 50 0.00 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 kthreadd
1488541252 3 0.00 0.00 0.00 0.00 0 0.00 0.00 0 0 0.00 0.00 0.00 0.00 0.59 0.00 migration/0
1488541252 4 0.00 0.00 0.00 0.00 0 0.00 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 ksoftirqd/0
1488541252 5 0.00 0.00 0.00 0.00 0 0.00 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 migration/0
1488541252 6 0.00 0.00 0.00 0.00 0 0.00 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 watchdog/0
......
1488541264 18523 0.00 0.20 0.00 0.20 5 10.78 0.00 137774940 3002232 0.57 0.00 0.00 0.00 1.96 0.20 /home/digoal/pgsql9.6/bin/postgres
1488541264 18549 0.00 0.00 0.00 0.00 61 0.00 0.00 140892 2028 0.00 0.00 0.00 0.00 0.00 0.00 postgres: logger process
1488541264 18552 0.00 0.00 0.00 0.00 0 0.00 0.00 137779116 5509520 1.04 0.00 0.00 0.00 0.00 0.00 postgres: checkpointer process
1488541264 18554 0.00 0.00 0.00 0.00 20 0.00 0.00 137776328 1058572 0.20 0.00 0.00 0.00 3.92 0.00 postgres: writer process
1488541264 18556 0.00 0.00 0.00 0.00 15 0.00 0.00 137774940 19120 0.00 0.00 0.00 0.00 3.92 0.00 postgres: wal writer process
1488541264 18557 0.00 0.00 0.00 0.00 21 2.94 0.00 137779092 3404 0.00 0.00 0.00 0.00 3.92 0.00 postgres: autovacuum launcher process
1488541264 18559 0.00 0.00 0.00 0.00 11 0.00 0.00 142988 2092 0.00 0.00 0.00 0.00 0.00 0.00 postgres: archiver process last was 0000000100000030000000B2
1488541264 18561 0.00 0.00 0.00 0.00 53 4.90 0.00 143556 2624 0.00 0.00 317.65 317.65 4.12 0.20 postgres: stats collector process
参考
man pidstat
PIDSTAT(1) Linux User’s Manual PIDSTAT(1)
NAME
pidstat - Report statistics for Linux tasks.
SYNOPSIS
pidstat [ -C comm ] [ -d ] [ -h ] [ -I ] [ -l ] [ -p { pid [,...] | SELF | ALL } ] [ -r ] [ -t ] [ -T { TASK | CHILD | ALL } ] [ -u ] [ -V ] [ -w ] [ interval [ count ] ]
DESCRIPTION
The pidstat command is used for monitoring individual tasks currently being managed by the Linux kernel. It writes to standard output activities for every task selected with option -p or for every task
managed by the Linux kernel if option -p ALL has been used. Not selecting any tasks is equivalent to specifying -p ALL but only active tasks (tasks with non-zero statistics values) will appear in the
report.
The pidstat command can also be used for monitoring the child processes of selected tasks. Read about option -T below.
The interval parameter specifies the amount of time in seconds between each report. A value of 0 (or no parameters at all) indicates that tasks statistics are to be reported for the time since system
startup (boot). The count parameter can be specified in conjunction with the interval parameter if this one is not set to zero. The value of count determines the number of reports generated at interval
seconds apart. If the interval parameter is specified without the count parameter, the pidstat command generates reports continuously.
You can select information about specific task activities using flags. Not specifying any flags selects only CPU activity.
OPTIONS
-C comm
Display only tasks whose command name includes the string comm.
-d Report I/O statistics (kernels 2.6.20 and later only). The following values are displayed:
PID
The identification number of the task being monitored.
kB_rd/s
Number of kilobytes the task has caused to be read from disk per second.
kB_wr/s
Number of kilobytes the task has caused, or shall cause to be written to disk per second.
kB_ccwr/s
Number of kilobytes whose writing to disk has been cancelled by the task. This may occur when the task truncates some dirty pagecache. In this case, some IO which another task has been
accounted for will not be happening.
Command
The command name of the task.
-h Display all activities horizontally on a single line. This is intended to make it easier to be parsed by other programs.
-I In an SMP environment, indicate that tasks CPU usage (as displayed by option -u ) should be divided by the total number of processors.
-l Display the process command name and all its arguments.
-p { pid [,...] | SELF | ALL }
Select tasks (processes) for which statistics are to be reported. pid is the process identification number. The SELF keyword indicates that statistics are to be reported for the pidstat process
itself, whereas the ALL keyword indicates that statistics are to be reported for all the tasks managed by the system.
-r Report page faults and memory utilization.
When reporting statistics for individual tasks, the following values are displayed:
PID
The identification number of the task being monitored.
minflt/s
Total number of minor faults the task has made per second, those which have not required loading a memory page from disk.
majflt/s
Total number of major faults the task has made per second, those which have required loading a memory page from disk.
VSZ
Virtual Size: The virtual memory usage of entire task in kilobytes.
RSS
Resident Set Size: The non-swapped physical memory used by the task in kilobytes.
Command
The command name of the task.
When reporting global statistics for tasks and all their children, the following values are displayed:
PID
The identification number of the task which is being monitored together with its children.
minflt-nr
Total number of minor faults made by the task and all its children, and collected during the interval of time.
majflt-nr
Total number of major faults made by the task and all its children, and collected during the interval of time.
Command
The command name of the task which is being monitored together with its children.
-t Also display statistics for threads associated with selected tasks.
This option adds the following values to the reports:
TGID
The identification number of the thread group leader.
TID
The identification number of the thread being monitored.
-T { TASK | CHILD | ALL }
This option specifies what has to be monitored by the pidstat command. The TASK keyword indicates that statistics are to be reported for individual tasks (this is the default option) whereas the
CHILD keyword indicates that statistics are to be globally reported for the selected tasks and all their children. The ALL keyword indicates that statistics are to be reported for individual tasks
and globally for the selected tasks and their children.
Note: Global statistics for tasks and all their children are not available for all options of pidstat. Also these statistics are not necessarily relevant to current time interval: The statistics of
a child process are collected only when it finishes or it is killed.
-u Report CPU utilization.
When reporting statistics for individual tasks, the following values are displayed:
PID
The identification number of the task being monitored.
%usr
Percentage of CPU used by the task while executing at the user level (application), with or without nice priority. Note that this field does NOT include time spent running a virtual processor.
%system
Percentage of CPU used by the task while executing at the system level (kernel).
%guest
Percentage of CPU spent by the task in virtual machine (running a virtual processor).
%CPU
Total percentage of CPU time used by the task. In an SMP environment, the task’s CPU usage will be divided by the total number of CPU’s if option -I has been entered on the command line.
CPU
Processor number to which the task is attached.
Command
The command name of the task.
When reporting global statistics for tasks and all their children, the following values are displayed:
PID
The identification number of the task which is being monitored together with its children.
usr-ms
Total number of milliseconds spent by the task and all its children while executing at the user level (application), with or without nice priority, and collected during the interval of time.
Note that this field does NOT include time spent running a virtual processor.
system-ms
Total number of milliseconds spent by the task and all its children while executing at the system level (kernel), and collected during the interval of time.
guest-ms
Total number of milliseconds spent by the task and all its children in virtual machine (running a virtual processor).
Command
The command name of the task which is being monitored together with its children.
-V Print version number then exit.
-w Report task switching activity (kernels 2.6.23 and later only). The following values are displayed:
PID
The identification number of the task being monitored.
cswch/s
Total number of voluntary context switches the task made per second. A voluntary context switch occurs when a task blocks because it requires a resource that is unavailable.
nvcswch/s
Total number of non voluntary context switches the task made per second. A involuntary context switch takes place when a task executes for the duration of its time slice and then is forced to
relinquish the processor.
Command
The command name of the task.
ENVIRONMENT
The pidstat command takes into account the following environment variable:
S_TIME_FORMAT
If this variable exists and its value is ISO then the current locale will be ignored when printing the date in the report header. The pidstat command will use the ISO 8601 format (YYYY-MM-DD)
instead.
EXAMPLES
pidstat 2 5
Display five reports of CPU statistics for every active task in the system at two second intervals.
pidstat -r -p 1643 2 5
Display five reports of page faults and memory statistics for PID 1643 at two second intervals.
pidstat -T CHILD -r 2 5
Display five reports of page faults statistics at two second intervals for the child processes of all tasks in the system. Only child processes with non-zero statistics values are displayed.
BUGS
/proc filesystem must be mounted for the pidstat command to work.
FILES
/proc contains various files with system statistics.
AUTHOR
Sebastien Godard (sysstat orange.fr)
SEE ALSO
sar(1), top(1), ps(1), mpstat(1), iostat(1), vmstat(8)
http://pagesperso-orange.fr/sebastien.godard/
Linux DECEMBER 2008 PIDSTAT(1)
http://linoxide.com/linux-command/linux-pidstat-monitor-statistics-procesess/
http://www.cnblogs.com/ggjucheng/archive/2013/01/13/2858874.html
其他
mpstat
vmstat
top
sar
iostat
dstat
ps 
