lt_proctab is a collection of stored functions that can access the operating systems process table so that system statitics can be queried through the database.
Gets information about all LightDB processes. The list of all
processes is retrieved from
pg_stat_activity,
and process information is retrieved from the
/proc
system file.
lightdb@postgres=# select * from pg_proctab(); -[ RECORD 1 ]---------+----------------------------------------- pid | 64994 comm | lightdb fullcomm | lightdb: autovacuum launcher state | S ppid | 64986 pgrp | 64994 session | 64994 tty_nr | 0 tpgid | -1 flags | 4202560 minflt | 529 cminflt | 0 majflt | 0 cmajflt | 0 utime | 1 stime | 0 cutime | 0 cstime | 0 priority | 20 nice | 0 num_threads | 1 itrealvalue | 0 starttime | 3258371 vsize | 1902161920 rss | 3588 exit_signal | 17 processor | 3 rt_priority | 0 policy | 0 delayacct_blkio_ticks | 0 uid | 1001 username | lightdb rchar | 66914 wchar | 26 syscr | 72 syscw | 26 reads | 0 writes | 0 cwrites | 0
CPU information obtained from /proc/stat
.
lightdb@postgres=# select * from pg_cputime(); user | nice | system | idle | iowait --------+------+--------+----------+-------- 289580 | 61 | 29378 | 15540161 | 7253 (1 row)
Load information obtained from /proc/loadavg
.
lightdb@postgres=# select * from pg_loadavg(); load1 | load5 | load15 | last_pid -------+-------+--------+---------- 0.08 | 0.05 | 0.05 | 74363 (1 row)
Memory usage information obtained from
/proc/meminfo
.
lightdb@postgres=# select * from pg_memusage(); memused | memfree | memshared | membuffers | memcached | swapused | swapfree | swapcached ---------+---------+-----------+------------+-----------+----------+----------+------------ 4441516 | 3552556 | 0 | 2084 | 3770828 | 0 | 4064252 | 0 (1 row)
Disk usage information obtained from
/proc/diskstats
lightdb@postgres=# select * from pg_diskusage(); -[ RECORD 1 ]----+--------- major | 8 minor | 0 devname | sda reads_completed | 36385 reads_merged | 67 sectors_read | 2060883 readtime | 25260 writes_completed | 384347 writes_merged | 3697 sectors_written | 16852473 writetime | 351385 current_io | 0 iotime | 326759 totaliotime | 372183