PostgreSQL数据库psql连接报错connections on Unix domain socket “/pgsql/data/.s.PGSQL.5432“?

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 问题现象 

[postgres@lyp ~]$ pg_ctl -D /pgsql/data/ start
waiting for server to start....2021-10-15 01:42:31.606 CST [32453] LOG:  redirecting log output to logging collector process
2021-10-15 01:42:31.606 CST [32453] HINT:  Future log output will appear in directory "pg_log".
 done
server started
[postgres@lyp ~]$ psql
psql: error: could not connect to server: No such file or directory
        Is the server running locally and accepting
        connections on Unix domain socket "/pgsql/data/.s.PGSQL.5432"?
[postgres@lyp ~]$ 

问题分析

 查看log日志

[postgres@lyp pg_log]$ tail -100f postgresql-2021-10-15_014231.csv
2021-10-15 01:42:31.606 CST,,,32453,,61686c07.7ec5,1,,2021-10-15 01:42:31 CST,,0,LOG,00000,"ending log output to stderr",,"Future log output will go to log destination ""csvlog"".",,,,,,,"","postmaster"
2021-10-15 01:42:31.606 CST,,,32453,,61686c07.7ec5,2,,2021-10-15 01:42:31 CST,,0,LOG,00000,"starting PostgreSQL 13.2 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-36), 64-bit",,,,,,,,,"","postmaster"
2021-10-15 01:42:31.608 CST,,,32453,,61686c07.7ec5,3,,2021-10-15 01:42:31 CST,,0,LOG,00000,"listening on IPv6 address ""::1"", port 5432",,,,,,,,,"","postmaster"
2021-10-15 01:42:31.608 CST,,,32453,,61686c07.7ec5,4,,2021-10-15 01:42:31 CST,,0,LOG,00000,"listening on IPv4 address ""127.0.0.1"", port 5432",,,,,,,,,"","postmaster"
2021-10-15 01:42:31.610 CST,,,32453,,61686c07.7ec5,5,,2021-10-15 01:42:31 CST,,0,LOG,00000,"listening on Unix socket ""/tmp/.s.PGSQL.5432""",,,,,,,,,"","postmaster"
2021-10-15 01:42:31.612 CST,,,32455,,61686c07.7ec7,1,,2021-10-15 01:42:31 CST,,0,LOG,00000,"database system was shut down at 2021-10-15 01:42:16 CST",,,,,,,,,"","startup"
2021-10-15 01:42:31.613 CST,,,32453,,61686c07.7ec5,6,,2021-10-15 01:42:31 CST,,0,LOG,00000,"database system is ready to accept connections",,,,,,,,,"","postmaster"

        日志中看到socket在：/tmp/.s.PGSQL.5432，而psql却在找/pgsql/data/.s.PGSQL.5432

查看环境变量

[postgres@lyp ~]$ cat .bash_profile 
# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

# User specific environment and startup programs

PATH=$PATH:$HOME/.local/bin:$HOME/bin

export PATH

export PGHOME=/opt/pgsql13.2
export PGDATA=/pgsql/data
export PGHOST=/pgsql/data
export PGUSER=postgres
export PGPORT=5432
export PATH=$HOME/bin:$PGHOME/bin:$PATH
export LD_LIBRARY_PATH=$PGHOME/lib:$LD_LIBRARY_PATH
[postgres@lyp ~]$ 

查看参数unix_socket_directories

[postgres@lyp ~]$ cat /pgsql/data/postgresql.conf | grep unix_socket_directories
#unix_socket_directories = '/tmp'       # comma-separated list of directories
[postgres@lyp ~]$ 

解决办法

所以解决以上错误有两个办法：

1、删除环境变量的export PGHOST=/pgsql/data

2、设置参数unix_socket_directories=’/pgsql/data’；        ——重启生效