消失的postmaster进程

[postgres@rhel73 global]$ pwd/usr/local/pgsql/data/global[postgres@rhel73 global]$ ps -ef | grep -i  postroot      2220     1  0 03:43 ?        00:00:00 /usr/libexec/postfix/master -wpostfix   2222  2220  0 03:43 ?        00:00:00 qmgr -l -t unix -uroot      2549  2501  0 03:48 pts/0    00:00:00 su - postgrespostgres  2550  2549  0 03:48 pts/0    00:00:00 -bashpostgres  2632     1  0 03:51 pts/0    00:00:00 /usr/local/pgsql/bin/postgres -D /usr/local/pgsql/data--->>>只有这个.postgres  2634  2632  0 03:51 ?        00:00:00 postgres: checkpointer PRocess   postgres  2635  2632  0 03:51 ?        00:00:00 postgres: writer process   postgres  2636  2632  0 03:51 ?        00:00:00 postgres: wal writer process   postgres  2637  2632  0 03:51 ?        00:00:00 postgres: autovacuum launcher process   postgres  2638  2632  0 03:51 ?        00:00:00 postgres: stats collector process   postgres  7255  2550  0 12:03 pts/0    00:00:00 ps -efpostgres  7256  2550  0 12:03 pts/0    00:00:00 grep --color=auto -i post[postgres@rhel73 global]$ ps -ef | grep mastroot      2220     1  0 03:43 ?        00:00:00 /usr/libexec/postfix/master -wpostgres  7638  2550  0 12:46 pts/0    00:00:00 grep --color=auto mast[postgres@rhel73 global]$ ps -ef | grep masterroot      2220     1  0 03:43 ?        00:00:00 /usr/libexec/postfix/master -wpostgres  7640  2550  0 12:46 pts/0    00:00:00 grep --color=auto master[postgres@rhel73 global]$ [postgres@rhel73 global]$ [postgres@rhel73 global]$ [postgres@rhel73 global]$ which postmaster/usr/local/pgsql/bin/postmaster[postgres@rhel73 global]$ [postgres@rhel73 global]$ [postgres@rhel73 global]$ cd ..[postgres@rhel73 data]$ ls -lrttotal 56-rw-------. 1 postgres postgres     4 Feb 28 07:57 PG_VERSIONdrwx------. 2 postgres postgres     6 Feb 28 07:57 pg_twophasedrwx------. 2 postgres postgres     6 Feb 28 07:57 pg_tblspcdrwx------. 2 postgres postgres     6 Feb 28 07:57 pg_statdrwx------. 2 postgres postgres     6 Feb 28 07:57 pg_snapshotsdrwx------. 2 postgres postgres     6 Feb 28 07:57 pg_serialdrwx------. 2 postgres postgres     6 Feb 28 07:57 pg_replslotdrwx------. 4 postgres postgres    36 Feb 28 07:57 pg_multixactdrwx------. 4 postgres postgres    39 Feb 28 07:57 pg_logicaldrwx------. 2 postgres postgres     6 Feb 28 07:57 pg_dynshmemdrwx------. 2 postgres postgres     6 Feb 28 07:57 pg_commit_ts-rw-------. 1 postgres postgres 22282 Feb 28 07:57 postgresql.conf-rw-------. 1 postgres postgres    88 Feb 28 07:57 postgresql.auto.conf-rw-------. 1 postgres postgres  1636 Feb 28 07:57 pg_ident.conf-rw-------. 1 postgres postgres  4468 Feb 28 07:57 pg_hba.confdrwx------. 3 postgres postgres    60 Feb 28 07:57 pg_xlogdrwx------. 2 postgres postgres    18 Feb 28 07:57 pg_subtransdrwx------. 2 postgres postgres    18 Feb 28 07:57 pg_clogdrwx------. 6 postgres postgres    54 Feb 28 08:02 base-rw-------. 1 postgres postgres    78 Mar  2 03:51 postmaster.piddrwx------. 2 postgres postgres    18 Mar  2 03:51 pg_notify-rw-------. 1 postgres postgres    59 Mar  2 03:51 postmaster.optsdrwx------. 2 postgres postgres  4096 Mar  2 03:51 globaldrwx------. 2 postgres postgres    25 Mar  2 12:56 pg_stat_tmp[postgres@rhel73 data]$ pwd/usr/local/pgsql/data[postgres@rhel73 data]$ cat postmaster.pid2632/usr/local/pgsql/data14884446645432/tmplocalhost  5432001         0[postgres@rhel73 data]$ ps -ef | grep 5432postgres  7746  2550  0 12:57 pts/0    00:00:00 grep --color=auto 5432[postgres@rhel73 data]$ [postgres@rhel73 data]$ [postgres@rhel73 data]$ [postgres@rhel73 data]$ cat postmaster.opts/usr/local/pgsql/bin/postgres "-D" "/usr/local/pgsql/data"[postgres@rhel73 data]$ pwd/usr/local/pgsql/data[postgres@rhel73 data]$ 问了问公司的技术总监,结果是这样的:
postmaster is a deprecated alias of postgres.如上来自:https://www.postgresql.org/docs/9.5/static/app-postmaster.html结论是这样的:PG9.5之前的postmaster进程实际上就是PG9.5及其以后版本中第一个启动的postgres进程,该进程的ospid(操作系统进程的进程号)在$PGDATA/下的postmaster.pid中有记录.