PostgreSQL on Linux 最佳部署手册

原文作者为德哥，digoal ``` 背景 数据库的安装一直以来都挺复杂的，特别是Oracle，现在身边都还有安装Oracle数据库赚外快的事情。 PostgreSQL其实安装很简单，但是那仅仅是可用，并不是好用。很多用户使用默认的方法安装好数据库之后，然后测试一通性能，发现性能不行就不用了。 原因不用说，多方面没有优化的结果。 PostgreSQL数据库为了适应更多的场景能使用，默认的参数都设得非常保守，通常需要优化，比如检查点，SHARED BUFFER等。 本文将介绍一下PostgreSQL on Linux的最佳部署方法，其实在我的很多文章中都有相关的内容，但是没有总结成一篇文档。 安装常用包

yum -y install coreutils glib2 lrzsz mpstat dstat sysstat e4fsprogs xfsprogs ntp readline-devel zlib-devel openssl-devel pam-devel libxml2-devel libxslt-devel python-devel tcl-devel gcc make smartmontools flex bison perl-devel perl-ExtUtils* openldap-devel

配置OS内核参数

vi /etc/sysctl.conf \#add by digoal.zhou


fs.aio-max-nr = 1048576


fs.file-max = 76724600


kernel.core_pattern= /data01/corefiles/core_%e_%u_%t_%s.%p


# /data01/corefiles事先建好，权限777


kernel.sem = 4096 2147483647 2147483646 512000


# 信号量, ipcs -l 或 -u 查看，每16个进程一组，每组信号量需要17个信号量。


kernel.shmall = 107374182


# 所有共享内存段相加大小限制(建议内存的80%)


kernel.shmmax = 274877906944


# 最大单个共享内存段大小(建议为内存一半), >9.2的版本已大幅降低共享内存的使用


kernel.shmmni = 819200


# 一共能生成多少共享内存段，每个PG数据库集群至少2个共享内存段


net.core.netdev_max_backlog = 10000


net.core.rmem_default = 262144


# The default setting of the socket receive buffer in bytes.


net.core.rmem_max = 4194304


# The maximum receive socket buffer size in bytes


net.core.wmem_default = 262144


# The default setting (in bytes) of the socket send buffer.

net.core.wmem_max = 4194304


# The maximum send socket buffer size in bytes.


net.core.somaxconn = 4096


net.ipv4.tcp_max_syn_backlog = 4096


net.ipv4.tcp_keepalive_intvl = 20


net.ipv4.tcp_keepalive_probes = 3


net.ipv4.tcp_keepalive_time = 60


net.ipv4.tcp_mem = 8388608 12582912 16777216


net.ipv4.tcp_fin_timeout = 5


net.ipv4.tcp_synack_retries = 2


net.ipv4.tcp_syncookies = 1


# 开启SYN Cookies。当出现SYN等待队列溢出时，启用cookie来处理，可防范少量的SYN攻击


net.ipv4.tcp_timestamps = 1


# 减少time_wait


net.ipv4.tcp_tw_recycle = 0


# 如果=1则开启TCP连接中TIME-WAIT套接字的快速回收，但是NAT环境可能导致连接失败，建议服务端关闭它 net.ipv4.tcp_tw_reuse = 1


# 开启重用。允许将TIME-WAIT套接字重新用于新的TCP连接


net.ipv4.tcp_max_tw_buckets = 262144


net.ipv4.tcp_rmem = 8192 87380 16777216


net.ipv4.tcp_wmem = 8192 65536 16777216


net.nf_conntrack_max = 1200000


net.netfilter.nf_conntrack_max = 1200000


vm.dirty_background_bytes = 409600000


# 系统脏页到达这个值，系统后台刷脏页调度进程 pdflush（或其他）自动将(dirty_expire_centisecs/100）秒前的脏页刷到磁盘


vm.dirty_expire_centisecs = 3000


# 比这个值老的脏页，将被刷到磁盘。3000表示30秒。

vm.dirty_ratio = 95


# 如果系统进程刷脏页太慢，使得系统脏页超过内存 95 % 时，则用户进程如果有写磁盘的操作（如fsync, fdatasync等调用），则需要主动把系统脏页刷出。


# 有效防止用户进程刷脏页，在单机多实例，并且使用CGROUP限制单实例IOPS的情况下非常有效。 vm.dirty_writeback_centisecs = 100


# pdflush（或其他）后台刷脏页进程的唤醒间隔， 100表示1秒。


vm.extra_free_kbytes = 4096000


vm.min_free_kbytes = 2097152


vm.mmap_min_addr = 65536


vm.overcommit_memory = 0


# 在分配内存时，允许少量over malloc, 如果设置为 1, 则认为总是有足够的内存，内存较少的测试环境可以使用 1 . vm.overcommit_ratio = 90


# 当overcommit_memory = 2 时，用于参与计算允许指派的内存大小。

vm.swappiness = 0


# 关闭交换分区


vm.zone_reclaim_mode = 0


# 禁用 numa, 或者在vmlinux中禁止.

net.ipv4.ip_local_port_range = 40000 65535


# 本地自动分配的TCP, UDP端口号范围


# vm.nr_hugepages = 66536


# 建议shared buffer设置超过64GB时使用大页，页大小 /proc/meminfo Hugepagesize


配置OS资源限制

vi /etc/security/limits.conf

* soft nofile 1024000


* hard nofile 1024000

* soft nproc unlimited


* hard nproc unlimited


* soft core unlimited


* hard core unlimited


* soft memlock unlimited


* hard memlock unlimited

配置OS防火墙 （建议按业务场景设置，我这里先清掉）

iptables -F selinux

如果没有这方面的需求，建议禁用

vi /etc/sysconfig/selinux

SELINUX=disabled


SELINUXTYPE=targeted

部署文件系统 注意SSD对齐，延长寿命，避免写放大。

parted -s /dev/sda mklabel gpt
parted -s /dev/sda mkpart primary 1MiB 100% 

格式化

mkfs.ext4 /dev/sda1 -m 0 -O extent,uninit_bg -E lazy_itable_init=1 -T largefile -L u01 

建议使用的ext4 mount选项

vi /etc/fstab

LABEL=u01 /u01     ext4        defaults,noatime,nodiratime,nodelalloc,barrier=0,data=writeback 0 0 

# mount -a 编译器 建议使用较新的编译器，安装 gcc 6.2.0 略

cd ~

tar -jxvf gcc6.2.0.tar.bz2


tar -jxvf python2.7.12.tar.bz2

vi /etc/ld.so.conf

/home/digoal/gcc6.2.0/lib
/home/digoal/gcc6.2.0/lib64
/home/digoal/python2.7.12/lib 

ldconfig

环境变量

vi ~/env_pg.sh

export PS1="$USER@`/bin/hostname -s`-> "


export PGPORT=$1


export PGDATA=/$2/digoal/pg_root$PGPORT


export.utf8


export PGHOME=/home/digoal/pgsql9.6


export LD_LIBRARY_PATH=/home/digoal/gcc6.2.0/lib:/home/digoal/gcc6.2.0/lib64:/home/digoal/python2.7.12/lib:$PGHOME/lib:/lib64:/usr/lib64:/usr/local/lib64:/lib:/usr/lib:/usr/local/lib:$LD_LIBRARY_PATH export PATH=/home/digoal/gcc6.2.0/bin:/home/digoal/python2.7.12/bin:/home/digoal/cmake3.6.3/bin:$PGHOME/bin:$PATH:.


export DATE=`date +"%Y%m%d%H%M"`

export MANPATH=$PGHOME/share/man:$MANPATH


export PGHOST=$PGDATA


export PGUSER=postgres


export PGDATABASE=postgres alias rm='rm -i' alias ll='ls -lh' unalias vi

编译PostgreSQL 建议使用NAMED_POSIX_SEMAPHORES

. ~/env_pg.sh 1921 u01 cd postgresql-9.6.1

export USE_NAMED_POSIX_SEMAPHORES=1


LIBS=-lpthread CC="/home/digoal/gcc6.2.0/bin/gcc" CFLAGS="-O3 -flto" ./configure --prefix=/home/digoal/pgsql9.6

LIBS=-lpthread CC="/home/digoal/gcc6.2.0/bin/gcc" CFLAGS="-O3 -flto" make world -j 64 LIBS=-lpthread CC="/home/digoal/gcc6.2.0/bin/gcc" CFLAGS="-O3 -flto" make install-world 

初始化数据库集群 pg_xlog建议放在IOPS最好的分区。 . ~/env_pg.sh 1921 u01

initdb -D $PGDATA -E UTF8 --locale=C -U postgres -X /u02/digoal/pg_xlog$PGPORT 

配置postgresql.conf 以PostgreSQL 9.6, 512G内存主机为例 最佳到文件末尾即可，重复的会以末尾的作为有效值。

$ vi postgresql.conf

listen_addresses = '0.0.0.0'


port = 1921


max_connections = 5000


unix_socket_directories = '.'


tcp_keepalives_idle = 60


tcp_keepalives_interval = 10


tcp_keepalives_count = 10


shared_buffers = 128GB


maintenance_work_mem = 4GB


dynamic_shared_memory_type = posix


vacuum_cost_delay = 0


bgwriter_delay = 10ms


bgwriter_lru_maxpages = 1000


bgwriter_lru_multiplier = 10.0


bgwriter_flush_after = 0


max_parallel_workers_per_gather = 0


old_snapshot_threshold = -1


backend_flush_after = 0


wal_level = replica


synchronous_commit = off full_page_writes = on


wal_buffers = 1GB


wal_writer_delay = 10ms


wal_writer_flush_after = 0


checkpoint_timeout = 30min


max_wal_size = 256GB


min_wal_size = 64GB


checkpoint_completion_target = 0.05


checkpoint_flush_after = 0


max_wal_senders = 5


random_page_cost = 1.0


parallel_tuple_cost = 0 parallel_setup_cost = 0


min_parallel_relation_size = 0


effective_cache_size = 300GB


force_parallel_mode = off


log_destination = 'csvlog'


logging_collector = on


log_truncate_on_rotation = on


log_checkpoints = on

log_connections = on


log_disconnections = on


log_error_verbosity = verbose


log_timezone = 'PRC'

autovacuum = on


log_autovacuum_min_duration = 0


autovacuum_max_workers = 16


autovacuum_naptime = 15s autovacuum_vacuum_scale_factor = 0.02


autovacuum_analyze_scale_factor = 0.01


vacuum_freeze_table_age = 1500000000


vacuum_multixact_freeze_table_age = 1500000000


datestyle = 'iso, mdy'


timezone = 'PRC' lc_messages = 'C'


lc_monetary = 'C'


lc_numeric = 'C'


lc_time = 'C'


default_text_search_config = 'pg_catalog.english'


shared_preload_libraries='pg_stat_statements'

配置pg_hba.conf 避免不必要的访问，开放允许的访问，建议务必使用密码访问。 $ vi pg_hba.conf

host all all 0.0.0.0/0 md5 启动数据库 pg_ctl start 好了，你的PostgreSQL数据库基本上部署好了，可以愉快的玩耍了。 ```