PostgreSQL 参数优化设置 32GB内存（推荐） 自动初始化参数shell脚本

1.修改参数列表 （1）执行计划 enable_nestloop = off #默认为on enable_seqscan = off #默认为on enable_indexscan = on enable_bitmapscan = on max_connections = 1000 #默认为100   （2）内存相关 shared_buffers = 16GB # 默认为128MB effective_cache_size = 24GB #默认为4GB work_mem = 32MB temp_buffers = 32MB wal_buffers = 512MB maintenance_work_mem = 2GB   （3）autovacuum autovacuum = on autovacuum_max_workers = 3 #默认为3 autovacuum_work_mem = 256MB autovacuum_vacuum_scale_factor = 0.05 #默认为0.2   （4）检查点 max_wal_size = 4GB #默认为1GB min_wal_size = 1GB #默认为80MB checkpoint_completion_target = 0.9 #默认为0.5 checkpoint_timeout = 30min #默认为5min   （5）日志 log_destination = csvlog log_directory = pg_log logging_collector = on log_min_duration_statement = 800 log_rotation_size = 1024MB log_truncate_on_rotation = on log_filename = 'xl_log_%a.log'   2.参数设置公式

这个shell脚本可以使用shell的关联数组对

[code]#!/bin/bash
#command to execute script: su - postgres -c "./create.sh"
#default value refer to standard server(cpu:6cores,memory:32G,storage:12T)
#value according to the actual situation

#List of parameters to be modified
:<<!
enable_seqscan = off
enable_indexscan = on
enable_bitmapscan = on
max_connections = 1000
shared_buffers = 16GB
effective_cache_size = 24GB
work_mem = 32MB
temp_buffers = 32MB
wal_buffers = 512MB
maintenance_work_mem = 2GB
autovacuum_max_workers = 3
autovacuum_work_mem = 256MB
checkpoint_timeout = 30min
max_wal_size = 4GB
min_wal_size = 1GB
checkpoint_completion_target = 0.9
log_destination = csvlog
log_directory = pg_log
logging_collector = on
log_min_duration_statement = 800
log_rotation_size = 1024MB
log_truncate_on_rotation = on
log_filename = 'xl_log_%a.log'
!

ERROR="\033[41;37m ERROR \033[0m"
INFO="\033[42;37m INFO \033[0m"
WARN="\033[43;37m WARN \033[0m"
COMMON_ERROR="some error happened, specific information please see console output"

# Array of parameters
declare -A parameter_array
parameter_array=([enable_seqscan]=off [enable_indexscan]=on [enable_bitmapscan]=on [max_connections]=1000 [shared_buffers]=16GB
[effective_cache_size]=24GB [work_mem]=32MB [temp_buffers]=32MB [wal_buffers]=512MB [maintenance_work_mem]=2GB
[autovacuum_max_workers]=3 [autovacuum_work_mem]=256MB [checkpoint_timeout]=30min [max_wal_size]=4GB
[min_wal_size]=1GB [checkpoint_completion_target]=0.9 [log_destination]=csvlog [log_directory]=pg_log
[logging_collector]=on [log_min_duration_statement]=800 [log_rotation_size]=1024MB [log_truncate_on_rotation]=on [log_filename]=viid_log_%a.log )

#default value :
pgctl_path=
data_directory=
memory=

# check command exit value, 0 is success
function check_fun(){
status=$?
error=${COMMON_ERROR}
if [[ 0 -ne ${status} ]] ; then
echo -e "${ERROR} ${error}"
exit 1
fi
}

# prepare conditions
function prepare_conditions(){
data_directory=$(psql -qtAX  -c "show data_directory" | sed 's/[ ]//g')
check_fun
if [[ ! -d "${data_directory}" ]] ; then
echo -e "${ERROR} database's data directory does not exist"
exit 1
fi
# physical machine environment
memory=$(grep MemTotal /proc/meminfo | awk '{print $2 / 1024 / 1024}' | sed 's/\.[0-9]*//' | tail -n 1)
check_fun
# docker environment
memory_limit=$(($(awk '{print $1}' /sys/fs/cgroup/memory/memory.limit_in_bytes) / 1024 / 1024 /1024))
check_fun
# comparing the two, choose the smaller one.
if [[ "${memory_limit}" -le "${memory}" ]] ; then
memory=${memory_limit}
fi
}

# calculate parameters
function calculate_parameters(){
# 50%*memory
parameter_array[shared_buffers]=$((memory * 1024 / 2))"MB"
# 75%*memory
parameter_array[effective_cache_size]=$((memory * 1024 * 3 / 4 ))"MB"
# <1%
parameter_array[work_mem]=${memory}"MB"
# <1%
parameter_array[temp_buffers]=${memory}"MB"
# 32GB => 512MB
parameter_array[wal_buffers]=$((memory * 16 ))"MB"
# 32GB => 2048MB
parameter_array[maintenance_work_mem]=$((memory * 64 ))"MB"
}

# modify parameters
function modify_parameters(){
# modify parameters by modifying file postgresql.conf:
for parameter in ${!parameter_array[*]}
do
#check whether the parameters have been modified
# PostgreSQL's default parameter configuration example: enable_seqscan = on
# viid's example: enable_seqscan='on'
check_out=$(grep "^${parameter}=" "${data_directory}"/postgresql.conf | grep -v '#' | tail -n 1)
# process sleep
sleep 0.2s
if [[ -z "${check_out}" ]] ; then
echo "${parameter}='${parameter_array[${parameter}]}'" >> "${data_directory}"/postgresql.conf
check_fun
echo -e "${INFO} modify ${parameter} successfully"
else
if [[ "${check_out}" = "${parameter}='${parameter_array[${parameter}]}'" ]] ; then
echo -e "${INFO} ${parameter} is already configured, then skip this step"
else
sed -i s!^"${check_out}"!"${parameter}='${parameter_array[${parameter}]}'"!g  "${data_directory}"/postgresql.conf
check_fun
echo -e "${INFO} modify ${parameter} successfully"
fi
fi
done
}

# create directory(pg_log and pg_arch), and set user postgres permission
function create_dir(){
directory_array=("pg_arch" "pg_log")
for directory in ${directory_array[*]};
do
# process sleep
sleep 0.2s
if [[ ! -d "${data_directory}/${directory}" ]] ; then
mkdir -p "${data_directory}"/"${directory}"
echo -e "${INFO} path ${data_directory}/${directory} create successfully"
else
echo -e "${INFO} ${data_directory}/${directory} is already exists, then skip this step"
fi
# set user postgres permission
chown postgres:postgres "${data_directory}"/"${directory}"
done
}

# because the environment is different, need to find the path of the database restart command 'pg_ctl'
function find_cmd(){
result=$(find / -name pg_ctl 2> /dev/null | grep bin/pg_ctl$ | tail -n 1 )
# check whether the path exists
if [[ -z "${result}" ]] ; then
echo -e "${ERROR} database restart command 'pg_ctl' not exists"
echo -e "${ERROR} please check to see if the database is installed or the command directory does not have permission to access it"
exit 1
else
echo -e "${INFO} database restart command 'pg_ctl' path: ${result}"
pgctl_path=${result}
fi
}

# user choose whether to restart or not
function check_restart(){
read -r -p "Is it necessary to restart database immediately?[Enter YES or NO]:" result
if [[ "${result,,}" = "yes" ]] ; then
echo -e "${INFO} start to restart database"
${pgctl_path} restart -D "${data_directory}" >& /dev/null
if [[ 0 -ne ${status} ]] ; then
echo -e "${ERROR} restart database failed"
exit 12
fi
elif [[ "${result,,}" = "no" ]] ; then
echo -e "${WARN} please restart database manually"
echo -e "${WARN} if you don't restart, database may not be available"
exit 11
else
echo -e "${ERROR} invalid input,please enter again"
check_restart
fi
}

# ******* start *******
# prepare conditions:memory ,data_directory
prepare_conditions
# calculate parameters
calculate_parameters
# modify parameters
modify_parameters
# create directory(pg_log and pg_arch)
create_dir
# the path of the database restart command 'pg_ctl'
find_cmd
# remind user that they need to restart database to take effect
# process sleep
sleep 0.5s
echo -e ""
echo -e "*******************************************************************"
echo -e "*                                                                 *"
echo -e "*                                                                 *"
echo -e "*                restart database to take effect                  *"
echo -e "*                                                                 *"
echo -e "*                                                                 *"
echo -e "*******************************************************************"
# process sleep
sleep 0.5s
# user choose whether to restart or not
# check_restart
echo -e "${INFO} start to restart database"
${pgctl_path} restart -D "${data_directory}" >& /dev/null