简介

本文以工业界测试模型TPC-C为测试模型，介绍PostgreSQL数据库从系统层面的优化到数据库层面的优化方法。 TPmC从 256195.32 提升到 606466.31 是如何做到的。

测试环境介绍

• 16核开HT共32线程
• 256G 1600MHz 内存
• 万兆网卡
• 3 块 6.4TB AliFlash PCI-E SSD
• 逻辑卷条带
• XFS
• 数据块对齐

XFS文件系统优化

主要分3块：

1. 逻辑卷优化部分
2. XFS mkfs 优化部分
3. XFS mount 优化部分

以上几个部分都可以通过man手册查看，了解原理和应用场景后着手优化。

man lvcreate
man xfs
man mkfs.xfs
man mount

逻辑卷优化部分

对于不在lvm列表的设备，可能要先修改lvm.conf，添加设备号才行。否则不能创建PV。

# cat /proc/devices
252 shannon
[root@localhost ~]# vi /etc/lvm/lvm.conf
    # types = [ "fd", 16 ]
    types = [ "shannon", 252 ]

1. 创建PV前，将块设备对齐（对齐的目的是避免双写，因为SSD有最小写入单元，如果没有对齐，可能出现SSD写多个块），前面1MB最好不要分配，从2048 sector开始分配。（使用pvcreate的–dataalignment参数也可以达到同样的目的。）

    fdisk -c -u /dev/dfa
    start  2048
    end    + (2048*n) - 1

   或者使用parted创建分区。

   LVM的layout，创建PV时，也需要对齐DATA的数据。 从4MB处开始分配DATA EXTENSION： # pvcreate --dataalignment 4M /dev/sdc

   1st PE 即数据开始位置。

    [root@digoal ~]# pvs -o+pe_start
      PV         VG     Fmt  Attr PSize  PFree  1st PE
      /dev/sda2  centos lvm2 a--  19.51g 40.00m   1.00m
      /dev/sdc          lvm2 ---  20.00g 20.00g   4.00m

   列出所有可以查看的flag pvs -o+

2. 创建lv主要指定2个参数，条带数量，和pv数量一致即可，如果PV本身是一个RAID设备，根据RAID的块设备个数来定条带数。 例如RAID5 5块盘，去除1个校验数据，取4作为条带数。RAID10 10块盘，取5作为条带数。RAID0 10块盘，取10作为条带数。

        -i, --stripes Stripes
    Gives the number of stripes.  This is equal to the number of physical volumes to scatter the logical volume.

   条带大小，和数据库块大小一致，例如postgresql默认为 8KB。

         -I, --stripesize StripeSize
    Gives the number of kilobytes for the granularity of the stripes.
    StripeSize must be 2^n (n = 2 to 9) for metadata in LVM1 format.  For metadata in LVM2 format, the stripe size may be a larger power of 2 but must not exceed the physical extent size.

   创建快照时，指定的参数chunksize, 最好和数据库的块大小一致, 例如postgresql默认为 8KB。

         -c, --chunksize ChunkSize
    Power of 2 chunk size for the snapshot logical volume between 4k and 512k.

   例如： 预留2GB给xfs的LOG DEV

    #lvcreate -i 3 -I 8 -n lv02 -L 2G vgdata01
      Logical volume "lv02" created
    #lvcreate -i 3 -I 8 -n lv01 -l 100%FREE vgdata01
      Logical volume "lv01" created
    #lvs
      LV   VG       Attr   LSize   Origin Snap%  Move Log Copy%  Convert
      lv01 vgdata01 -wi-a-  17.29t
      lv02 vgdata01 -wi-a-  2g

XFS mkfs 优化部分

首先要搞清楚XFS的layout

xfs包含3个section，data、log、realtime files。默认情况下 log存在data里面，没有realtime。所有的section都是由最小单位block组成，初始化xfs是-b指定block size。

1. data 包含 metadata(inode, 目录, 间接块), user file data, non-realtime files data被拆分成多个allocation group，mkfs.xfs时可以指定group的个数，以及单个group的SIZE。 group越多，可以并行进行的文件和块的allocation就越多。你可以认为单个组的操作是串行的，多个组是并行的。但是组越多，消耗的CPU会越多，需要权衡。对于并发写很高的场景，可以多一些组（例如一台主机跑了很多小的数据库，每个数据库都很繁忙的场景下）

2. log 存储metadata的log，修改metadata前，必须先记录log，然后才能修改data section中的metadata。也用于crash后的恢复。

3. realtime 被划分为很多个小的extents, 要将文件写入到 realtime section中，必须使用xfsctl改一下文件描述符的bit位，并且一定要在数据写入前完成。在realtime中的文件大小是realtime extents的倍数关系。

mkfs.xfs优化

1. data section allocation group count数量和AGSIZE相乘等于块设备大小。 AG count数量多少和用户需求的并行度相关。 同时AG SIZE的取值范围是16M到1TB，PostgreSQL 建议1GB左右。 -b size=8192 与数据库块大小一致 （但不是所有的xfs版本都支持大于4K的block size，所以如果你发现mount失败并且告知只支持4K以下的BLOCK，那么请重新格式化） -d agcount=9000,sunit=16,swidth=48 假设有9000个并发写操作，使用9000个allocation groups (单位512 bytes) 与lvm或RAID块设备的条带大小对齐 与lvm或RAID块设备条带跨度大小对齐，以上对应3*8 例如 -i 3 -I 8。

2. log section 最好放在SSD上，速度越快越好。最好不要使用cgroup限制LOG块设备的iops操作。

3. realtime section 不需要的话，不需要创建。

agsize绝对不能是条带宽度的倍数。(假设条带数为3，条带大小为8K，则宽度为24K) 如果根据指定agcount算出的agsize是swidth的倍数，会弹出警告： 例如下面的例子， agsize=156234 blks 是 swidth=6 blks 的倍数 26039。 给出的建议是减掉一个stripe unit即8K，即156234 blks - sunit 2 blks = 156232 blks。 156232 blks换算成字节数= 156232*4096 = 639926272 bytes 或 156232*4 = 624928K

#mkfs.xfs -f -b size=4096 -l logdev=/dev/mapper/vgdata01-lv01,size=2136997888,sunit=16 -d agcount=30000,sunit=16,swidth=48 /dev/mapper/vgdata01-lv02
Warning: AG size is a multiple of stripe width.  This can cause performance
problems by aligning all AGs on the same disk.  To avoid this, run mkfs with
an AG size that is one stripe unit smaller, for example 156232.
meta-data=/dev/mapper/vgdata01-lv02 isize=256    agcount=30000, agsize=156234 blks
         =                       sectsz=4096  attr=2, projid32bit=1
         =                       crc=0        finobt=0
data     =                       bsize=4096   blocks=4686971904, imaxpct=5
         =                       sunit=2      swidth=6 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
log      =/dev/mapper/vgdata01-lv01 bsize=4096   blocks=521728, version=2
         =                       sectsz=512   sunit=2 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

对于上面这个mkfs.xfs操作，改成以下

#mkfs.xfs -f -b size=4096 -l logdev=/dev/mapper/vgdata01-lv01,size=2136997888,sunit=16 -d agsize=639926272,sunit=16,swidth=48 /dev/mapper/vgdata01-lv02

或

#mkfs.xfs -f -b size=4096 -l logdev=/dev/mapper/vgdata01-lv01,size=2136997888,sunit=16 -d agsize=624928k,sunit=16,swidth=48 /dev/mapper/vgdata01-lv02

输出如下

meta-data=/dev/mapper/vgdata01-lv02 isize=256    agcount=30001, agsize=156232 blks  (约600MB)
         =                       sectsz=4096  attr=2, projid32bit=1
         =                       crc=0        finobt=0
data     =                       bsize=4096   blocks=4686971904, imaxpct=5
         =                       sunit=2      swidth=6 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
log      =/dev/mapper/vgdata01-lv01 bsize=4096   blocks=521728, version=2
         =                       sectsz=512   sunit=2 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

XFS mount 优化部分

nobarrier largeio 针对数据仓库，流媒体这种大量连续读的应用 nolargeio 针对OLTP logbsize=262144 指定 log buffer logdev= 指定log section对应的块设备，用最快的SSD。 noatime,nodiratime swalloc 条带对齐 allocsize=16M delayed allocation writeout的buffer io大小 inode64 Indicates that XFS is allowed to create inodes at any location in the filesystem

mount.xfs 例子

#mount -t xfs -o allocsize=16M,inode64,nobarrier,nolargeio,logbsize=262144,noatime,nodiratime,swalloc,logdev=/dev/mapper/vgdata01-lv02 /dev/mapper/vgdata01-lv01 /data01

xfsctl 优化部分

略

排错

#mount -o noatime,swalloc /dev/mapper/vgdata01-lv01 /data01
mount: Function not implemented

原因是用了不支持的块大小

[ 5736.642924] XFS (dm-0): File system with blocksize 8192 bytes. Only pagesize (4096) or less will currently work.
[ 5736.695146] XFS (dm-0): SB validate failed with error -38.

问题排除

# mkfs.xfs -f -b size=4096 -l logdev=/dev/mapper/vgdata01-lv02,size=2136997888,sunit=16 -d agcount=9000,sunit=16,swidth=48 /dev/mapper/vgdata01-lv01
meta-data=/dev/mapper/vgdata01-lv01 isize=256    agcount=9000, agsize=515626 blks
         =           sectsz=512   attr=2
data     =           bsize=4096   blocks=4640621568, imaxpct=5
         =           sunit=2      swidth=6 blks
naming   =version 2  bsize=4096   ascii-ci=0
log      =/dev/mapper/vgdata01-lv02 bsize=4096   blocks=521728, version=2
         =           sectsz=512   sunit=2 blks, lazy-count=1
realtime =none       extsz=4096   blocks=0, rtextents=0

mount时指定logdev

#mount -t xfs -o allocsize=16M,inode64,nobarrier,nolargeio,logbsize=262144,noatime,nodiratime,swalloc,logdev=/dev/mapper/vgdata01-lv02 /dev/mapper/vgdata01-lv01 /data01

安装benchmarksql

http://sourceforge.net/projects/benchmarksql/

下载安装 JDK7

http://www.oracle.com/technetwork/cn/java/javase/downloads/jdk7-downloads-1880260.html
wget http://download.oracle.com/otn-pub/java/jdk/7u79-b15/jdk-7u79-linux-x64.rpm
rpm -ivh jdk-7u79-linux-x64.rpm

检查包安装位置(使用rpm安装时也可以直接指定位置)

rpm -ql jdk
...
/usr/java/jdk1.7.0_79/bin/java
...

配置JAVA环境变量

$  export JAVA_HOME=/usr/java/jdk1.7.0_79
$  export PATH=$JAVA_HOME/bin:$PATH
$  export CLASSPATH=.:$CLASSPATH

下载最新java版本对应的postgresql jdbc jar

wget https://jdbc.postgresql.org/download/postgresql-9.4.1207.jre7.jar
mv postgresql-9.4.1207.jre7.jar benchmarksql-4.1.0/lib/

配置benchmarksql，使用新的postgresql java驱动

$ vi runBenchmark.sh
java -cp .:../lib/postgresql-9.4.1207.jre7.jar:../lib/log4j-1.2.17.jar:../lib/apache-log4j-extras-1.1.jar:../dist/BenchmarkSQL-4.1.jar -Dprop=$1 jTPCC
$ vi runLoader.sh
java -cp .:../lib/postgresql-9.4.1207.jre7.jar:../dist/BenchmarkSQL-4.1.jar -Dprop=$1 LoadData $2 $3 $4 $5
$ vi runSQL.sh
myCP="../lib/postgresql-9.4.1207.jre7.jar"
myCP="$myCP:../dist/BenchmarkSQL-4.1.jar"
myOPTS="-Dprop=$1"
myOPTS="$myOPTS -DcommandFile=$2"
java -cp .:$myCP $myOPTS ExecJDBC

修改log4j，减少日志打印量。priority改成info，只输出最终结果，不输出产生订单的日志。

$ vi log4j.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j='http://jakarta.apache.org/log4j/'>
<appender name="console" class="org.apache.log4j.ConsoleAppender">
<param name="Threshold" value="info"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d %5p - %m%n"/>
</layout>
</appender>
<appender name="R" class="org.apache.log4j.rolling.RollingFileAppender">
<param name="Append" value="True" />
<rollingPolicy class="org.apache.log4j.rolling.TimeBasedRollingPolicy">
<param name="FileNamePattern" value="log/archive/benchmarksql.%d{yyyyMMddHHmm}.log"/>
<param name="ActiveFileName" value="log/benchmarksql.log"/>
</rollingPolicy>
<triggeringPolicy class="org.apache.log4j.rolling.SizeBasedTriggeringPolicy">
<param name="MaxFileSize" value="1"/>
</triggeringPolicy>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%5p\t[%d{yyyy-MM-dd HH:mm:ss.SSS}]\t%t \t%m%n"/>
</layout>
<filter class="org.apache.log4j.filter.StringMatchFilter">
<param name="StringToMatch" value ="\n" />
<param name="AcceptOnMatch" value="false" />
</filter>
</appender>
<appender name="E" class="org.apache.log4j.rolling.RollingFileAppender">
<param name="Append" value="True" />
<param name="Threshold" value="warn"/>
<rollingPolicy class="org.apache.log4j.rolling.TimeBasedRollingPolicy">
<param name="FileNamePattern" value="log/BenchmarkSQLError.%d.log"/>
<param name="ActiveFileName" value="log/BenchmarkSQLError.log"/>
</rollingPolicy>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%5p\t[%d{yyyy-MM-dd HH:mm:ss.SSS}]\t%t \t%m%n"/>
</layout>
</appender>
<root>
<priority value="info"/>
<appender-ref ref="R"/>
<appender-ref ref="E"/>
</root>
</log4j:configuration>

系统配置优化

内核配置
/etc/grub.conf
numa=off
elevator=deadline
编译器版本
gcc version 4.4.6 20110731 (Red Hat 4.4.6-3) (GCC)
/etc/sysctl.conf
vm.swappiness = 0
kernel.shmmax=135497418752
net.core.rmem_max = 4194304
net.core.wmem_max = 4194304
net.core.rmem_default = 262144
net.core.wmem_default = 262144
net.ipv4.ip_local_port_range = 9000 65535
kernel.sem = 50100 64128000 50100 1280
vm.dirty_background_bytes = 102400000
vm.dirty_ratio = 80
vm.nr_hugepages = 102352
/etc/security/limits.conf
* soft nofile 655360
* hard nofile 655360
* soft nproc 655360
* hard nproc 655360
* soft stack unlimited
* hard stack unlimited
* soft   memlock    250000000
* hard   memlock    250000000
块设备预读
blockdev --setra 16384 /dev/dfa
blockdev --setra 16384 /dev/dfb
blockdev --setra 16384 /dev/dfc
blockdev --setra 16384 /dev/dm-0

安装PostgreSQL

PostgreSQL编译项

./configure --prefix=/u02/digoal/soft_bak/pgsql9.5 --with-blocksize=8 --with-pgport=1921 --with-perl --with-python --with-tcl --with-openssl --with-pam --with-ldap --with-libxml --with-libxslt --enable-thread-safety
gmake world -j32
gmake install-world -j32

配置postgres环境变量

$ vi env_pg.sh
export PS1="$USER@`/bin/hostname -s`-> "
export PGPORT=1921
export PGDATA=/data01/pgdata/pg_root
export LANG=en_US.utf8
export PGHOME=/u02/digoal/soft_bak/pgsql9.5
export LD_LIBRARY_PATH=$PGHOME/lib:/lib64:/usr/lib64:/usr/local/lib64:/lib:/usr/lib:/usr/local/lib:$LD_LIBRARY_PATH
export DATE=`date +"%Y%m%d%H%M"`
export PATH=$PGHOME/bin:$PATH:.
export MANPATH=$PGHOME/share/man:$MANPATH
export PGHOST=$PGDATA
export PGDATABASE=postgres
export PGUSER=postgres
alias rm='rm -i'
alias ll='ls -lh'
unalias vi

配置postgresql.conf

$ vi $PGDATA/postgresql.conf
port = 1921     # (change requires restart)
max_connections = 300       # (change requires restart)
unix_socket_directories = '.'   # comma-separated list of directories
shared_buffers = 32GB       # min 128kB
huge_pages = try           # on, off, or try
maintenance_work_mem = 2GB  # min 1MB
dynamic_shared_memory_type = posix      # the default is the first option
bgwriter_delay = 10ms       # 10-10000ms between rounds
wal_level = minimal  # minimal, archive, hot_standby, or logical
synchronous_commit = off    # synchronization level;
full_page_writes = off      # recover from partial page writes, 有备份和归档就可以关闭它, crash后从备份恢复, 放partial write
wal_buffers = 16MB           # min 32kB, -1 sets based on shared_buffers
wal_writer_delay = 10ms         # 1-10000 milliseconds
max_wal_size = 32GB
effective_cache_size = 240GB
log_destination = 'csvlog'  # Valid values are combinations of
logging_collector = on          # Enable capturing of stderr and csvlog
log_truncate_on_rotation = on           # If on, an existing log file with the

编辑benchmarksql连接配置和压测配置

1000 个仓库，约5亿数据量。

$ vi props.pg
driver=org.postgresql.Driver
conn=jdbc:postgresql://localhost:1921/postgres
user=postgres
password=123
warehouses=1000
terminals=96
//To run specified transactions per terminal- runMins must equal zero
runTxnsPerTerminal=0
//To run for specified minutes- runTxnsPerTerminal must equal zero
runMins=1
//Number of total transactions per minute
limitTxnsPerMin=0
//The following five values must add up to 100
//The default percentages of 45, 43, 4, 4 & 4 match the TPC-C spec
newOrderWeight=40
paymentWeight=36
orderStatusWeight=8
deliveryWeight=8
stockLevelWeight=8

生成测试数据

配置postgres用户默认搜索路径

$ psql
psql (9.5.0)
Type "help" for help.
postgres=# alter role postgres set search_path='benchmarksql','public';

创建用于存放生成CSV的目录

$ mkdir /u02/digoal/soft_bak/benchcsv

修改benchmarksql sqlTableCopies，指定目录

$ vi sqlTableCopies
copy benchmarksql.warehouse
  (w_id, w_ytd, w_tax, w_name, w_street_1, w_street_2, w_city, w_state, w_zip)
  from '/u02/digoal/soft_bak/benchcsv/warehouse.csv' WITH CSV;
copy benchmarksql.item
  (i_id, i_name, i_price, i_data, i_im_id)
  from '/u02/digoal/soft_bak/benchcsv/item.csv' WITH CSV;
copy benchmarksql.stock
  (s_i_id, s_w_id, s_quantity, s_ytd, s_order_cnt, s_remote_cnt, s_data,
   s_dist_01, s_dist_02, s_dist_03, s_dist_04, s_dist_05,
   s_dist_06, s_dist_07, s_dist_08, s_dist_09, s_dist_10)
  from '/u02/digoal/soft_bak/benchcsv/stock.csv' WITH CSV;
copy benchmarksql.district
  (d_id, d_w_id, d_ytd, d_tax, d_next_o_id, d_name, d_street_1,
   d_street_2, d_city, d_state, d_zip)
  from '/u02/digoal/soft_bak/benchcsv/district.csv' WITH CSV;
copy benchmarksql.customer
  (c_id, c_d_id, c_w_id, c_discount, c_credit, c_last, c_first, c_credit_lim,
   c_balance, c_ytd_payment, c_payment_cnt, c_delivery_cnt, c_street_1,
   c_street_2, c_city, c_state, c_zip, c_phone, c_since, c_middle, c_data)
  from '/u02/digoal/soft_bak/benchcsv/customer.csv' WITH CSV;
copy benchmarksql.history
  (hist_id, h_c_id, h_c_d_id, h_c_w_id, h_d_id, h_w_id, h_date, h_amount, h_data)
  from '/u02/digoal/soft_bak/benchcsv/cust-hist.csv' WITH CSV;
copy benchmarksql.oorder
  (o_id, o_w_id, o_d_id, o_c_id, o_carrier_id, o_ol_cnt, o_all_local, o_entry_d)
  from '/u02/digoal/soft_bak/benchcsv/order.csv' WITH CSV;
copy benchmarksql.order_line
  (ol_w_id, ol_d_id, ol_o_id, ol_number, ol_i_id, ol_delivery_d,
   ol_amount, ol_supply_w_id, ol_quantity, ol_dist_info)
  from '/u02/digoal/soft_bak/benchcsv/order-line.csv' WITH CSV;
copy benchmarksql.new_order
  (no_w_id, no_d_id, no_o_id)
  from '/u02/digoal/soft_bak/benchcsv/new-order.csv' WITH CSV;

建立表结构

$ cd benchmarksql-4.1.0/run
$ ./runSQL.sh props.pg sqlTableCreates

生成CSV

$ ./runLoader.sh props.pg numWarehouses 1000 fileLocation /u02/digoal/soft_bak/benchcsv/

1000个仓库的数据量69 GB：

total 69G
-rw-r--r-- 1 digoal users 2.0G Jan  9 15:53 cust-hist.csv
-rw-r--r-- 1 digoal users  16G Jan  9 15:53 customer.csv
-rw-r--r-- 1 digoal users 898K Jan  9 15:12 district.csv
-rw-r--r-- 1 digoal users 7.0M Jan  9 14:22 item.csv
-rw-r--r-- 1 digoal users  95M Jan  9 16:14 new-order.csv
-rw-r--r-- 1 digoal users 1.3G Jan  9 16:14 order.csv
-rw-r--r-- 1 digoal users  22G Jan  9 16:14 order-line.csv
-rw-r--r-- 1 digoal users  28G Jan  9 15:12 stock.csv
-rw-r--r-- 1 digoal users  84K Jan  9 14:22 warehouse.csv

导入数据库

$ ./runSQL.sh props.pg sqlTableCopies

创建约束和索引

$ ./runSQL.sh props.pg sqlIndexCreates

备份

$ pg_dump -f /u02/digoal/soft_bak/benchmarksql.dmp -F c -n benchmarksql postgres

阶段1 TPC-C 压测

nohup ./runBenchmark.sh props.pg >/dev/null 2>./errrun.log &

测试结果

 INFO   [2016-01-09 22:03:39.963]       Thread-7        Term-00, Measured tpmC (NewOrders) = 102494.46
 INFO   [2016-01-09 22:03:39.963]       Thread-7        Term-00, Measured tpmTOTAL = 256195.32
 INFO   [2016-01-09 22:03:39.964]       Thread-7        Term-00, Session Start     = 2016-01-09 21:53:39
 INFO   [2016-01-09 22:03:39.964]       Thread-7        Term-00, Session End       = 2016-01-09 22:03:39
 INFO   [2016-01-09 22:03:39.964]       Thread-7        Term-00, Transaction Count = 2563088

主机信息，截取压测第9分钟的top, iostat数据。

TOP
top - 22:02:09 up 3 days, 12:55,  3 users,  load average: 19.23, 15.97, 8.37
Tasks: 619 total,  10 running, 609 sleeping,   0 stopped,   0 zombie
Cpu(s): 35.0%us,  9.4%sy,  0.0%ni, 52.6%id,  0.1%wa,  0.0%hi,  2.9%si,  0.0%st
Mem:  264643396k total, 241719372k used, 22924024k free,    36672k buffers
Swap: 18825200k total,        0k used, 18825200k free, 196557376k cached
iostat -x
avg-cpu:  %user   %nice %system %iowait  %steal   %idle
          35.07    0.00   12.30    0.12    0.00   52.51
Device:         rrqm/s   wrqm/s     r/s     w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
dfa   0.00     0.00   57.40  743.40   918.40 11849.00    15.94     0.02    0.03   0.03   2.08
dfb   0.00     0.00   57.20  740.40   915.20 11829.00    15.98     0.02    0.03   0.03   2.04
dfc   0.00     0.00   58.40  730.80   934.40 11675.80    15.98     0.03    0.03   0.03   2.52
dm-0  0.00     0.00  173.00 2213.20  2768.00 35331.40    15.97     0.08    0.03   0.03   7.02

PostgreSQL可以使用oprofile或perf top跟踪统计，可以参考这里，找到需要优化的代码就靠它了。

CPU: Intel Ivy Bridge microarchitecture, speed 2600 MHz (estimated)
Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit mask of 0x00 (No unit mask) count 100000
vma      samples  %        app name     symbol name
007a7780 751274    5.1565  /soft/digoal/soft_bak/pgsql9.5/bin/postgres hash_search_with_hash_value
004a92f0 574315    3.9419  /soft/digoal/soft_bak/pgsql9.5/bin/postgres _bt_compare
006a4bd0 514473    3.5312  /soft/digoal/soft_bak/pgsql9.5/bin/postgres LWLockAcquire
0078a090 510962    3.5071  /soft/digoal/soft_bak/pgsql9.5/bin/postgres SearchCatCache
007bc3a0 484601    3.3262  /soft/digoal/soft_bak/pgsql9.5/bin/postgres AllocSetAlloc
006969c0 442341    3.0361  /soft/digoal/soft_bak/pgsql9.5/bin/postgres GetSnapshotData
00498930 352134    2.4170  /soft/digoal/soft_bak/pgsql9.5/bin/postgres heap_hot_search_buffer
005b8f70 279718    1.9199  /soft/digoal/soft_bak/pgsql9.5/bin/postgres ExecInitExpr
006895d0 249377    1.7117  /soft/digoal/soft_bak/pgsql9.5/bin/postgres PinBuffer
006a4220 168770    1.1584  /soft/digoal/soft_bak/pgsql9.5/bin/postgres LWLockRelease
007ac620 161861    1.1110  /soft/digoal/soft_bak/pgsql9.5/bin/postgres pg_encoding_mbcliplen
007a2180 161090    1.1057  /soft/digoal/soft_bak/pgsql9.5/bin/postgres FunctionCall2Coll
004aaa80 153079    1.0507  /soft/digoal/soft_bak/pgsql9.5/bin/postgres _bt_checkkeys
007a3950 147078    1.0095  /soft/digoal/soft_bak/pgsql9.5/bin/postgres fmgr_info_cxt_security
0049bce0 136680    0.9381  /soft/digoal/soft_bak/pgsql9.5/bin/postgres heap_page_prune_opt
0048c8f0 130807    0.8978  /soft/digoal/soft_bak/pgsql9.5/bin/postgres hash_any
006b2e50 130564    0.8962  /soft/digoal/soft_bak/pgsql9.5/bin/postgres PostgresMain
0046c790 121776    0.8358  /soft/digoal/soft_bak/pgsql9.5/bin/postgres slot_deform_tuple
......

阶段1 PostgreSQL 9.5.0 TPmC : 256195.32

阶段1 性能瓶颈分析

从系统统计信息可以分析得到, 系统还有大量空闲CPU，IO资源，所以极限性能应该不止于此。

阶段2 TPC-C 优化

benchmarksql放到另一台主机，主机间万兆网同一交换机下互联。

为了突破测试程序的极限，开4个schema，每个schema负责1000个仓库，数据量总共20亿左右，入库后的数据总量约400GB。每个测试程序对付一个schema。终端数保持一致，每个测试程序开24个终端，一共96个终端。

让benchmarksql支持多个schema

benchmarksql 默认编译好的，还有配置都是用的benchmarksql 这个schema，如果我们想对一个数据库用多个schema来压性能，就需要开多个benchmarksql终端来压。这里就涉及到benchmarksql需要支持多个schema，每个benchmarksql连一个schema。 目录结构：

drwxr-xr-x 2 digoal users 4096 Jan 10 13:24 build
-rwxr-xr-x 1 digoal users 1112 Jan 10 13:24 build.xml
drwxr-xr-x 2 digoal users 4096 Jan 10 13:24 dist
-rw-r--r-- 1 digoal users  128 Jan 10 13:24 env_java.sh
-rwxr-xr-x 1 digoal users 1927 Jan 10 13:24 HOW-TO-RUN.txt
drwxr-xr-x 2 digoal users 4096 Jan 10 13:24 lib
-rwxr-xr-x 1 digoal users 2825 Jan 10 13:24 README.txt
drwxr-xr-x 3 digoal users 4096 Jan 10 13:24 run
drwxr-xr-x 6 digoal users 4096 Jan 10 13:24 src

需要修改的地方：

src/LoadData/LoadData.java
src/client/jTPCCTerminal.java
run/props.ora
run/props.pg
run/sqlIndexCreates
run/sqlIndexDrops
run/sqlTableCopies
run/sqlTableCreates
run/sqlTableDrops
run/sqlTableTruncates

把所有的benchmarksql替换成新的schema name，例如 test01

sed -i "s/benchmarksql/test01/g" src/LoadData/LoadData.java
sed -i "s/benchmarksql/test01/g" src/client/jTPCCTerminal.java
sed -i "s/benchmarksql/test01/g" run/props.ora
sed -i "s/benchmarksql/test01/g" run/props.pg
sed -i "s/benchmarksql/test01/g" run/sqlIndexCreates
sed -i "s/BENCHMARKSQL/TEST01/g" run/sqlIndexCreates
sed -i "s/benchmarksql/test01/g" run/sqlIndexDrops
sed -i "s/benchmarksql/test01/g" run/sqlTableCopies
sed -i "s/benchmarksql/test01/g" run/sqlTableCreates
sed -i "s/benchmarksql/test01/g" run/sqlTableDrops
sed -i "s/benchmarksql/test01/g" run/sqlTableTruncates

然后使用ant重新打包工程，如果没有安装ant，可以用yum install -y ant安装它。

使用ant重新打包benchmarksql.jar

$ant -buildfile ./build.xml
Buildfile: ./build.xml
Trying to override old definition of task javac
init:
compile:
    [javac] Compiling 16 source files to /soft/digoal/soft_bak/benchmarksql-4.1.0_oracle01/build
    [javac] Note: /soft/digoal/soft_bak/benchmarksql-4.1.0_oracle01/src/client/jTPCCTerminal.java uses unchecked or unsafe operations.
    [javac] Note: Recompile with -Xlint:unchecked for details.
dist:
      [jar] Building jar: /soft/digoal/soft_bak/benchmarksql-4.1.0_oracle01/dist/BenchmarkSQL-4.1.jar
BUILD SUCCESSFUL
Total time: 2 seconds

现在benchmarksql使用的是test01这个schema。使用同样的方法，生成支持test02,test03,test04 schema的benchmarksql版本。

创建4个数据库，分别为test01、test02、test03、test04，将阶段1 pg_dump导出的数据导入到这4个数据库, 并将schema重命名为对应的test01、test02、test03、test04。

测试数据量

postgres=# \l+
   List of databases
   Name    |  Owner   | Encoding | Collate | Ctype |   Access privileges   |  Size   | Tablespace |    Description
-----------+----------+----------+---------+-------+-----------------------+---------+------------+--------------------------------------------
 test01    | test01   | UTF8     | C       | C     |           | 100 GB  | pg_default |
 test02    | test02   | UTF8     | C       | C     |           | 100 GB  | pg_default |
 test03    | test03   | UTF8     | C       | C     |           | 100 GB  | pg_default |
 test04    | test04   | UTF8     | C       | C     |           | 100 GB  | pg_default |

benchmarksql软件目录

$ ll
drwxr-xr-x 7 digoal users 4.0K Jan 10 14:41 benchmarksql-4.1.0_pg01
drwxr-xr-x 7 digoal users 4.0K Jan 10 14:41 benchmarksql-4.1.0_pg02
drwxr-xr-x 7 digoal users 4.0K Jan 10 14:41 benchmarksql-4.1.0_pg03
drwxr-xr-x 7 digoal users 4.0K Jan 10 14:41 benchmarksql-4.1.0_pg04

配置每个benchmarksql的props.pg，修改对应的连接。 例如：

$cat run/props.pg
driver=org.postgresql.Driver
conn=jdbc:postgresql://xxx.xxx.xxx.xxx:1921/test01?preparedStatementCacheSizeMiB=10
user=test01
password=123
warehouses=1000
terminals=20
//To run specified transactions per terminal- runMins must equal zero
runTxnsPerTerminal=0
//To run for specified minutes- runTxnsPerTerminal must equal zero
runMins=10
//Number of total transactions per minute
limitTxnsPerMin=0
//The following five values must add up to 100
//The default percentages of 45, 43, 4, 4 & 4 match the TPC-C spec
newOrderWeight=40
paymentWeight=36
orderStatusWeight=8
deliveryWeight=8
stockLevelWeight=8

配置数据库pg_hba.conf，允许测试机连接。

vi $PGDATA/pg_hba.conf
host all all 0.0.0.0/0 md5
pg_ctl reload

阶段2 TPC-C 压测

cd benchmarksql-4.1.0_pg01/run
nohup ./runBenchmark.sh props.pg >/dev/null 2>./errrun.log &
cd ../../benchmarksql-4.1.0_pg02/run
nohup ./runBenchmark.sh props.pg >/dev/null 2>./errrun.log &
cd ../../benchmarksql-4.1.0_pg03/run
nohup ./runBenchmark.sh props.pg >/dev/null 2>./errrun.log &
cd ../../benchmarksql-4.1.0_pg04/run
nohup ./runBenchmark.sh props.pg >/dev/null 2>./errrun.log &
cd ../..

阶段2 PostgreSQL 9.5.0 TPmC : 453058.64

$ cat benchmarksql-4.1.0_pg01/run/log/benchmarksql.log
 INFO   [2016-01-10 17:54:04.925]       Thread-22       Term-00, Measured tpmC (NewOrders) = 45416.28
 INFO   [2016-01-10 17:54:04.925]       Thread-22       Term-00, Measured tpmTOTAL = 113487.61
 INFO   [2016-01-10 17:54:04.925]       Thread-22       Term-00, Session Start     = 2016-01-10 17:44:04
 INFO   [2016-01-10 17:54:04.925]       Thread-22       Term-00, Session End       = 2016-01-10 17:54:04
 INFO   [2016-01-10 17:54:04.925]       Thread-22       Term-00, Transaction Count = 1134913
$ cat benchmarksql-4.1.0_pg02/run/log/benchmarksql.log
 INFO   [2016-01-10 17:54:04.943]       Thread-12       Term-00, Measured tpmC (NewOrders) = 45292.48
 INFO   [2016-01-10 17:54:04.943]       Thread-12       Term-00, Measured tpmTOTAL = 113269.54
 INFO   [2016-01-10 17:54:04.943]       Thread-12       Term-00, Session Start     = 2016-01-10 17:44:04
 INFO   [2016-01-10 17:54:04.944]       Thread-12       Term-00, Session End       = 2016-01-10 17:54:04
 INFO   [2016-01-10 17:54:04.944]       Thread-12       Term-00, Transaction Count = 1132770
$ cat benchmarksql-4.1.0_pg03/run/log/benchmarksql.log
 INFO   [2016-01-10 17:54:04.955]       Thread-12       Term-00, Measured tpmC (NewOrders) = 45336.15
 INFO   [2016-01-10 17:54:04.955]       Thread-12       Term-00, Measured tpmTOTAL = 113247.19
 INFO   [2016-01-10 17:54:04.956]       Thread-12       Term-00, Session Start     = 2016-01-10 17:44:04
 INFO   [2016-01-10 17:54:04.956]       Thread-12       Term-00, Session End       = 2016-01-10 17:54:04
 INFO   [2016-01-10 17:54:04.956]       Thread-12       Term-00, Transaction Count = 1132537
$ cat benchmarksql-4.1.0_pg04/run/log/benchmarksql.log
 INFO   [2016-01-10 17:54:04.986]       Thread-23       Term-00, Measured tpmC (NewOrders) = 45231.67
 INFO   [2016-01-10 17:54:04.987]       Thread-23       Term-00, Measured tpmTOTAL = 113054.3
 INFO   [2016-01-10 17:54:04.987]       Thread-23       Term-00, Session Start     = 2016-01-10 17:44:04
 INFO   [2016-01-10 17:54:04.987]       Thread-23       Term-00, Session End       = 2016-01-10 17:54:04
 INFO   [2016-01-10 17:54:04.987]       Thread-23       Term-00, Transaction Count = 1130640
TPM ：
113487.61 + 113269.54 + 113247.19 + 113054.3 =  453058.64

第9分钟操作系统统计信息

TOP
top - 17:38:27 up 4 days,  8:32,  4 users,  load average: 78.54, 68.64, 37.22
Tasks: 658 total,  34 running, 624 sleeping,   0 stopped,   0 zombie
Cpu(s): 70.2%us, 15.7%sy,  0.0%ni,  5.5%id,  1.5%wa,  0.0%hi,  7.1%si,  0.0%st
Mem:  264643396k total, 229866068k used, 34777328k free,    59652k buffers
Swap: 18825200k total,        0k used, 18825200k free, 183529592k cached
iostat -x
avg-cpu:  %user   %nice %system %iowait  %steal   %idle
          71.39    0.00   22.47    1.26    0.00    4.88
Device:         rrqm/s   wrqm/s     r/s     w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
dfa   0.00     0.00 3659.33 7008.67 58538.67 112050.67    15.99     5.85    0.55   0.06  68.17
dfb   0.00     0.00 3714.67 6888.67 59418.67 110173.33    15.99     5.98    0.56   0.06  67.87
dfc   0.00     0.00 3709.00 6974.33 59328.00 111504.00    15.99     5.63    0.52   0.07  71.60
dm-0  0.00     0.00 11083.00 20870.33 177285.33 333706.67    15.99    17.60    0.55   0.03  92.10

测试过程oprofile报告

#/home/digoal/oprof/bin/opreport -l -f -w -x -t 0.5
Using /soft/digoal/soft_bak/oprof_test/oprofile_data/samples/ for samples directory.
WARNING! Some of the events were throttled. Throttling occurs when
the initial sample rate is too high, causing an excessive number of
interrupts.  Decrease the sampling frequency. Check the directory
/soft/digoal/soft_bak/oprof_test/oprofile_data/samples/current/stats/throttled
for the throttled event names.
CPU: Intel Ivy Bridge microarchitecture, speed 2600 MHz (estimated)
Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit mask of 0x00 (No unit mask) count 100000
vma      samples  %        app name     symbol name
007a7780 2632700   5.2511  /soft/digoal/soft_bak/pgsql9.5/bin/postgres hash_search_with_hash_value
004a92f0 1895924   3.7816  /soft/digoal/soft_bak/pgsql9.5/bin/postgres _bt_compare
006969c0 1844371   3.6787  /soft/digoal/soft_bak/pgsql9.5/bin/postgres GetSnapshotData
0078a090 1775031   3.5404  /soft/digoal/soft_bak/pgsql9.5/bin/postgres SearchCatCache
006a4bd0 1725350   3.4413  /soft/digoal/soft_bak/pgsql9.5/bin/postgres LWLockAcquire
007bc3a0 1565190   3.1219  /soft/digoal/soft_bak/pgsql9.5/bin/postgres AllocSetAlloc
00498930 1406694   2.8058  /soft/digoal/soft_bak/pgsql9.5/bin/postgres heap_hot_search_buffer
005b8f70 965646    1.9261  /soft/digoal/soft_bak/pgsql9.5/bin/postgres ExecInitExpr
006895d0 767078    1.5300  /soft/digoal/soft_bak/pgsql9.5/bin/postgres PinBuffer
004aaa80 617741    1.2321  /soft/digoal/soft_bak/pgsql9.5/bin/postgres _bt_checkkeys
007a2180 588043    1.1729  /soft/digoal/soft_bak/pgsql9.5/bin/postgres FunctionCall2Coll
006a4220 575864    1.1486  /soft/digoal/soft_bak/pgsql9.5/bin/postgres LWLockRelease
007ac620 485162    0.9677  /soft/digoal/soft_bak/pgsql9.5/bin/postgres pg_encoding_mbcliplen
007a3950 471102    0.9396  /soft/digoal/soft_bak/pgsql9.5/bin/postgres fmgr_info_cxt_security
0046c790 441548    0.8807  /soft/digoal/soft_bak/pgsql9.5/bin/postgres slot_deform_tuple
0048c8f0 425867    0.8494  /soft/digoal/soft_bak/pgsql9.5/bin/postgres hash_any
006b2e50 404548    0.8069  /soft/digoal/soft_bak/pgsql9.5/bin/postgres PostgresMain
007bd0f0 396510    0.7909  /soft/digoal/soft_bak/pgsql9.5/bin/postgres palloc
0049bce0 394201    0.7863  /soft/digoal/soft_bak/pgsql9.5/bin/postgres heap_page_prune_opt
007bce00 353243    0.7046  /soft/digoal/soft_bak/pgsql9.5/bin/postgres pfree
0049b300 335896    0.6700  /soft/digoal/soft_bak/pgsql9.5/bin/postgres heap_page_prune
0046c580 313145    0.6246  /soft/digoal/soft_bak/pgsql9.5/bin/postgres heap_getsysattr
006b14a0 311776    0.6219  /soft/digoal/soft_bak/pgsql9.5/bin/postgres exec_bind_message
007cb070 292106    0.5826  /soft/digoal/soft_bak/pgsql9.5/bin/postgres HeapTupleSatisfiesMVCC
007bd210 275282    0.5491  /soft/digoal/soft_bak/pgsql9.5/bin/postgres MemoryContextAllocZeroAligned
005b8530 273199    0.5449  /soft/digoal/soft_bak/pgsql9.5/bin/postgres ExecProject
00494ba0 266495    0.5315  /soft/digoal/soft_bak/pgsql9.5/bin/postgres heap_update
007bca10 265556    0.5297  /soft/digoal/soft_bak/pgsql9.5/bin/postgres AllocSetFree

阶段2 性能瓶颈分析

1. 单次IO请求响应较高，在0.06毫秒；
2. 系统调用占用的CPU百分比较高；
3. 数据库获取快照占用CPU较高，需要PostgreSQL代码层优化，本文暂时不涉及。

阶段3 TPC-C 优化

1. 开启PostgreSQL 预读, 预读数(n-1), 仅仅对hash 聚合有效, 有兴趣的同学可以看看PostgreSQL代码。n是条带数, 所以本例case effective_io_concurrency = 2 这个使用xfs的largeio参数效果是类似的，还有块设备的预读功能。 开启预读可能存在IO浪费的情况，例如全BUFFER命中的情况下。预读对于OLAP非常有效。

2. 开启大页支持, 开到168G;

    /etc/sysctl.conf
      vm.nr_hugepages = 102352
    sysctl -p
    /etc/security/limits.conf
      * soft   memlock    250000000
      * hard   memlock    250000000
      # 配置 memlock    大于  nr_hugepages   大于  shared_buffers

3. 使用数据块分组提交, commit_delay = 10, commit_siblings = 16 平滑检查点到0.8个周期，减少fsync dirty page IO影响。

    http://blog.163.com/digoal@126/blog/static/1638770402016011115141697/
    shared_buffers = 164GB       # min 128kB
    huge_pages = on           # on, off, or try
    maintenance_work_mem = 2GB  # min 1MB
    wal_buffers = 16MB           # min 32kB, -1 sets based on shared_buffers
    wal_writer_delay = 10ms         # 1-10000 milliseconds
    commit_delay = 10           # range 0-100000, in microseconds
    commit_siblings = 16        # range 1-1000
    checkpoint_timeout = 35min  # range 30s-1h
    max_wal_size = 320GB
    checkpoint_completion_target = 0.8     # checkpoint target duration, 0.0 - 1.0
    effective_cache_size = 240GB
    log_destination = 'csvlog'  # Valid values are combinations of
    logging_collector = on          # Enable capturing of stderr and csvlog
    log_truncate_on_rotation = on           # If on, an existing log file with the

阶段3 TPC-C 压测

$tail -n 5 benchmarksql-4.1.0_pg01/run/log/benchmarksql.log
 INFO   [2016-01-11 13:33:55.917]       Thread-14       Term-00, Measured tpmC (NewOrders) = 48151.07
 INFO   [2016-01-11 13:33:55.917]       Thread-14       Term-00, Measured tpmTOTAL = 120215.48
 INFO   [2016-01-11 13:33:55.917]       Thread-14       Term-00, Session Start     = 2016-01-11 13:23:55
 INFO   [2016-01-11 13:33:55.917]       Thread-14       Term-00, Session End       = 2016-01-11 13:33:55
 INFO   [2016-01-11 13:33:55.917]       Thread-14       Term-00, Transaction Count = 1202222
$tail -n 5 benchmarksql-4.1.0_pg02/run/log/benchmarksql.log
 INFO   [2016-01-11 13:33:55.971]       Thread-16       Term-00, Measured tpmC (NewOrders) = 48505.54
 INFO   [2016-01-11 13:33:55.971]       Thread-16       Term-00, Measured tpmTOTAL = 121182.26
 INFO   [2016-01-11 13:33:55.971]       Thread-16       Term-00, Session Start     = 2016-01-11 13:23:55
 INFO   [2016-01-11 13:33:55.972]       Thread-16       Term-00, Session End       = 2016-01-11 13:33:55
 INFO   [2016-01-11 13:33:55.972]       Thread-16       Term-00, Transaction Count = 1211858
$tail -n 5 benchmarksql-4.1.0_pg03/run/log/benchmarksql.log
 INFO   [2016-01-11 13:33:55.985]       Thread-4        Term-00, Measured tpmC (NewOrders) = 48119.61
 INFO   [2016-01-11 13:33:55.985]       Thread-4        Term-00, Measured tpmTOTAL = 120523.98
 INFO   [2016-01-11 13:33:55.985]       Thread-4        Term-00, Session Start     = 2016-01-11 13:23:55
 INFO   [2016-01-11 13:33:55.985]       Thread-4        Term-00, Session End       = 2016-01-11 13:33:55
 INFO   [2016-01-11 13:33:55.985]       Thread-4        Term-00, Transaction Count = 1205271
$tail -n 5 benchmarksql-4.1.0_pg04/run/log/benchmarksql.log
 INFO   [2016-01-11 13:33:55.958]       Thread-21       Term-00, Measured tpmC (NewOrders) = 48087.55
 INFO   [2016-01-11 13:33:55.958]       Thread-21       Term-00, Measured tpmTOTAL = 120461.29
 INFO   [2016-01-11 13:33:55.958]       Thread-21       Term-00, Session Start     = 2016-01-11 13:23:55
 INFO   [2016-01-11 13:33:55.958]       Thread-21       Term-00, Session End       = 2016-01-11 13:33:55
 INFO   [2016-01-11 13:33:55.958]       Thread-21       Term-00, Transaction Count = 1204638
TPM:
120215.48 + 121182.26 + 120523.98 + 120461.29 = 482383.01